[fix](trx-frontend-http): show one rig at a time on the digital modes page

A client connected to several rigs decodes all of them at once, and the decode stream carries every rig's traffic to every browser. The decoder panels listed all of it: a station a background rig copied on another band appeared in the APRS list next to the selected rig's, the vessel counts and the "latest seen" lines counted both, the status lines said "Receiving" because some other rig was, and the CW pane interleaved two rigs into one stream of text that read as neither. The page is about the rig the operator selected — the one whose spectrum is on screen and whose audio is playing — so each panel now shows what that rig heard: rows, counts, latest-seen, status, the live picture a WEFAX or SSTV frame is painting, and the CW pane. Nothing is dropped on the way in. The map is the whole station's view, has its own rig filter, and would empty out if the plugins stopped feeding it, so the histories still hold every rig and the map still plots them. That also means a switch loses nothing: the runtime gained a rerender hook, which the rig switch calls, and switching back brings the other rig's traffic up again. The CW pane is the exception — a running stream of text cannot be unpicked after the fact — so it starts empty on the rig switched to. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01SyX26FCpMQxiBoC7r5K1A7 Signed-off-by: Stan Grams <sjg@haxx.space>
[test](trx-frontend-http): type the frequency instead of filling it
2026-08-07 08:11:13 +02:00 · 2026-08-07 02:47:04 +02:00 · 2026-08-07 00:46:39 +02:00 · 2026-08-07 00:15:50 +02:00 · 2026-08-07 00:06:00 +02:00 · 2026-08-06 22:08:06 +02:00
76 changed files with 7882 additions and 3609 deletions
@@ -24,6 +24,12 @@ cargo test -p trx-core
 ./target/release/trx-server --print-config > trx-server.toml
 ./target/release/trx-client --print-config > trx-client.toml

+# Validate a config without starting anything (reports every problem)
+./target/release/trx-server --check-config --config trx-rs.toml
+
+# Regenerate trx-rs.toml.example after changing a config struct
+cargo run -p trx-config --example generate_example
+
 # Run server
 ./target/release/trx-server --config trx-server.toml
 # or via CLI args:
@@ -41,7 +47,8 @@ This is a Cargo workspace. All crates live under `src/`:
 src/
  trx-core/           # Core types, traits, state machine, controller (~3,500 LOC)
  trx-protocol/       # Client↔server protocol DTOs, auth, codec, mapping (~1,100 LOC)
-  trx-app/            # Shared application helpers (config paths, logging init)
+  trx-app/            # Shared application helpers (logging init, name normalization)
+  trx-config/         # Client + server config structs, loader, validators (~2,500 LOC)
  trx-reporting/      # PSKReporter UDP uplink + APRS-IS TCP uplink (~1,150 LOC)
  trx-server/         # Server binary: rig_task, audio pipeline, listener (~3,700 LOC)
    trx-backend/      # Backend abstraction trait + factory + dummy
@@ -2412,6 +2412,16 @@ dependencies = [
 "syn",
 ]

+[[package]]
+name = "serde_ignored"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "115dffd5f3853e06e746965a20dcbae6ee747ae30b543d91b0e089668bb07798"
+dependencies = [
+ "serde",
+ "serde_core",
+]
+
 [[package]]
 name = "serde_json"
 version = "1.0.149"
@@ -3031,10 +3041,6 @@ dependencies = [
 name = "trx-app"
 version = "0.1.0"
 dependencies = [
- "dirs",
- "serde",
- "thiserror 2.0.18",
- "toml",
 "tracing",
 "tracing-subscriber",
 ]
@@ -3115,6 +3121,7 @@ dependencies = [
 "toml",
 "tracing",
 "trx-app",
+ "trx-config",
 "trx-core",
 "trx-frontend",
 "trx-frontend-http",
@@ -3124,6 +3131,23 @@ dependencies = [
 "uuid",
 ]

+[[package]]
+name = "trx-config"
+version = "0.1.0"
+dependencies = [
+ "dirs",
+ "serde",
+ "serde_ignored",
+ "tempfile",
+ "thiserror 2.0.18",
+ "toml",
+ "toml_edit 0.22.27",
+ "tracing",
+ "trx-core",
+ "trx-decode-log",
+ "trx-reporting",
+]
+
 [[package]]
 name = "trx-configurator"
 version = "0.1.0"
@@ -3132,13 +3156,16 @@ dependencies = [
 "dialoguer",
 "tempfile",
 "tokio-serial",
+ "toml",
 "toml_edit 0.22.27",
+ "trx-config",
 ]

 [[package]]
 name = "trx-core"
 version = "0.1.0"
 dependencies = [
+ "base64",
 "flate2",
 "reqwest",
 "serde",
@@ -3294,6 +3321,7 @@ dependencies = [
 "trx-app",
 "trx-aprs",
 "trx-backend",
+ "trx-config",
 "trx-core",
 "trx-cw",
 "trx-decode-log",
@@ -18,6 +18,7 @@ members = [
    "src/trx-core",
    "src/trx-protocol",
    "src/trx-app",
+    "src/trx-config",
    "src/trx-reporting",
    "src/trx-server",
    "src/trx-server/trx-backend",
@@ -93,13 +93,17 @@ The wizard walks you through rig selection, serial port detection, audio
 settings, and frontend options, then writes `trx-server.toml` and
 `trx-client.toml`.

-Alternatively, generate example configs and edit them by hand:
+Alternatively, copy `trx-rs.toml.example` — a commented example covering every
+setting — and edit it by hand:

 ```bash
-./target/release/trx-server --print-config > trx-server.toml
-./target/release/trx-client --print-config > trx-client.toml
+cp trx-rs.toml.example trx-rs.toml
+./target/release/trx-server --check-config --config trx-rs.toml
 ```

+`--check-config` reports everything wrong with a config without starting
+anything. `--print-config` prints the same settings without comments.
+
 ### 4. Run

 ```bash
@@ -107,6 +111,9 @@ Alternatively, generate example configs and edit them by hand:
 ./target/release/trx-client --config trx-client.toml
 ```

+A single `trx-rs.toml` can configure both: the server reads its `[trx-server]`
+section and the client reads `[trx-client]`.
+
 Open the configured HTTP frontend address in a browser (default `http://localhost:8080`).

 ## How It Works
@@ -17,30 +17,61 @@ frontends.

 ## Configuration

-Both `trx-server` and `trx-client` use TOML configuration files. Use
-`--print-config` to generate a fully commented example.
+Both `trx-server` and `trx-client` read TOML. The server takes its settings
+from the `[trx-server]` section and the client from `[trx-client]`, so one
+`trx-rs.toml` can configure both — or each may live in its own file with the
+section header left off.
+
+`trx-rs.toml.example` in the repository root is a complete, commented example
+generated from the config definitions themselves. `--print-config` prints the
+same settings without the comments.

 ### File Locations

-**trx-server** lookup order:
-1. `--config <FILE>`
-2. `./trx-server.toml`
-3. `~/.trx-server.toml`
-4. `~/.config/trx-rs/server.toml`
-5. `/etc/trx-rs/server.toml`
+Both binaries use the same lookup order:

-**trx-client** lookup order:
 1. `--config <FILE>`
-2. `./trx-client.toml`
-3. `~/.config/trx-rs/client.toml`
-4. `/etc/trx-rs/client.toml`
+2. `./trx-rs.toml`
+3. `~/.config/trx-rs/trx-rs.toml`
+4. `/etc/trx-rs/trx-rs.toml`

 CLI arguments override config file values.

-### Environment Variables
+### Checking a Config

- `TRX_PLUGIN_DIRS`: additional plugin directories (path-separated), used by
-  both server and client.
+`--check-config` loads the file, reports every problem it finds — unknown keys,
+invalid values, listeners fighting over a port — and exits without starting
+anything:
+
+```bash
+trx-server --check-config --config trx-rs.toml
+trx-client --check-config --config trx-rs.toml
+```
+
+Unknown keys are warnings by default, so a config written for a newer version
+still runs on an older binary. `--strict-config` makes them fatal.
+
+`trx-configurator --check <FILE>` runs the same checks.
+
+### Environment Variables and Secrets
+
+Any string in the config may reference an environment variable as `${VAR}`;
+an unset variable is an error rather than an empty value.
+
+Credentials can be kept out of the config entirely by pointing at a file
+instead. Every secret has a `*_file` sibling — set one or the other, never
+both:
+
+| Inline key | File key | Contents |
+|------------|----------|----------|
+| `[listen.auth].tokens` | `tokens_file` | one token per line |
+| `[[remotes]].auth.token` | `token_file` | the token |
+| `[frontends.http.auth].rx_passphrase` | `rx_passphrase_file` | the passphrase |
+| `[frontends.http.auth].control_passphrase` | `control_passphrase_file` | the passphrase |
+| `[frontends.http_json.auth].tokens` | `tokens_file` | one token per line |
+
+Blank lines and `#` comments are ignored in the list files. A config that holds
+credentials inline and is readable by group or others is flagged at startup.

 ### Server Options

@@ -96,6 +127,7 @@ CLI arguments override config file values.
 | Field | Type | Default | Description |
 |-------|------|---------|-------------|
 | `tokens` | string[] | `[]` | Allowed auth tokens (empty = no auth) |
+| `tokens_file` | string | — | Read tokens from this file, one per line |

 #### `[audio]`

@@ -121,6 +153,13 @@ When audio is enabled, at least one of `rx_enabled` or `tx_enabled` must be true
 | `sample_rate` | u32 | `1920000` | IQ capture rate in Hz |
 | `bandwidth` | u32 | `1500000` | Hardware IF filter bandwidth in Hz |
 | `center_offset_hz` | i64 | `100000` | Offset from dial to avoid DC spur |
+| `spectrum_fft_size` | usize | `1024` | Spectrum FFT bins; power of two, 128–8192 |
+| `spectrum_interval_ms` | u64 | `50` | How often a spectrum frame is pushed to subscribed clients |
+
+Spectrum is the largest thing on the client connection. On a slow or
+high-latency link, halving `spectrum_fft_size` halves the bytes per frame (at
+half the frequency resolution) and raising `spectrum_interval_ms` sends fewer of
+them; see [Spectrum over a slow link](#spectrum-over-a-slow-link).

 #### `[sdr.gain]`

@@ -197,6 +236,29 @@ Notes:
 Files are appended in JSON Lines format. Supported date tokens: `%YYYY%`,
 `%MM%`, `%DD%` (UTC).

+#### `[decoders]`
+
+| Field | Type | Default | Description |
+|-------|------|---------|-------------|
+| `enabled` | string[] | all decoders | Decoders to run for this rig |
+| `output_dir` | string | `"$XDG_CACHE_HOME/trx-rs"` | Base directory for decoders that write images |
+
+Valid decoder names: `aprs`, `aprs_hf`, `ais`, `cw`, `ft2`, `ft4`, `ft8`,
+`lrpt`, `sstv`, `vdes`, `wefax`, `wspr` — the same names `[[sdr.channels]]`
+uses. An unrecognised name is a config error.
+
+Every decoder runs by default, which costs real CPU on a small machine. On a
+station that only works digital modes, listing just what you use is worth it:
+
+```toml
+[decoders]
+enabled = ["ft8", "ft4", "wspr"]
+```
+
+`sstv`, `wefax` and `lrpt` write images into a subdirectory of `output_dir`
+named after the decoder. `ais` and `vdes` additionally require an SDR channel
+configured to feed them.
+
 #### Multi-Rig Configuration

 Use `[[rigs]]` arrays instead of the flat `[rig]` section for multi-rig setups:
@@ -240,12 +302,32 @@ Rigs without an explicit `id` get auto-generated IDs like `ft817_0`, `soapysdr_1
 |-------|------|---------|-------------|
 | `url` | string | — | Server address (e.g. `localhost:4530`) |
 | `poll_interval_ms` | u64 | `750` | State poll interval |
+| `spectrum_interval_ms` | u64 | `50` | Spectrum frame interval; also settable per `[[remotes]]` entry |

 #### `[remote.auth]`

 | Field | Type | Default | Description |
 |-------|------|---------|-------------|
 | `token` | string | — | Auth token (must not be empty if set) |
+| `token_file` | string | — | Read the token from this file instead |
+
+#### `[[remotes]]`
+
+Preferred over the single `[remote]` section: one entry per rig, each mapping a
+short name to a server and an optional server-side rig id.
+
+| Field | Type | Default | Description |
+|-------|------|---------|-------------|
+| `name` | string | — | Short name used everywhere in the client |
+| `url` | string | — | Server address (`host:port`) |
+| `rig_id` | string | — | Rig id on a multi-rig server |
+| `auth.token` | string | — | Auth token |
+| `auth.token_file` | string | — | Read the token from this file instead |
+| `poll_interval_ms` | u64 | `750` | State poll interval |
+
+The `name` is the key used by `default_rig_name`, `rigctl.rig_ports`,
+`audio.rig_urls`, `audio.rig_ports` and `decode_history_retention_min_by_rig`.
+A name in any of those maps that no remote answers to is a config error.

 #### `[frontends.http]`

@@ -254,6 +336,31 @@ Rigs without an explicit `id` get auto-generated IDs like `ft817_0`, `soapysdr_1
 | `enabled` | bool | `true` | Enable web UI |
 | `listen` | ip | `127.0.0.1` | Bind address |
 | `port` | u16 | `8080` | Bind port |
+| `default_rig_name` | string | — | Remote selected on startup |
+| `initial_map_zoom` | u8 | `10` | Starting zoom for the APRS map |
+| `show_sdr_gain_control` | bool | `true` | Expose the RF gain control |
+| `bandplan_enabled` | bool | `true` | Show the bandplan strip |
+| `bandplan_region` | string | `"iaru_r1"` | `iaru_r1`, `iaru_r2`, or `iaru_r3` |
+| `decode_history_retention_min` | u64 | `1440` | Decode history retention |
+| `decode_history_retention_min_by_rig` | table | `{}` | Per-remote retention override |
+| `spectrum_coverage_margin_hz` | u32 | `50000` | Centre-retune guard margin |
+| `spectrum_usable_span_ratio` | f32 | `0.92` | Usable fraction of the sampled span |
+
+#### `[frontends.http.auth]`
+
+| Field | Type | Default | Description |
+|-------|------|---------|-------------|
+| `enabled` | bool | `false` | Require a passphrase |
+| `rx_passphrase` | string | — | Passphrase granting receive-only access |
+| `rx_passphrase_file` | string | — | Read it from this file instead |
+| `control_passphrase` | string | — | Passphrase granting full control |
+| `control_passphrase_file` | string | — | Read it from this file instead |
+| `tx_access_control_enabled` | bool | `true` | Hide TX from unauthenticated users |
+| `session_ttl_min` | u64 | `480` | Session lifetime |
+| `cookie_secure` | bool | `false` | Set Secure on the session cookie (needs HTTPS) |
+| `cookie_same_site` | string | `"Lax"` | `Strict`, `Lax`, or `None` |
+
+With `enabled = true`, at least one passphrase must be set.

 #### `[frontends.rigctl]`

@@ -261,7 +368,11 @@ Rigs without an explicit `id` get auto-generated IDs like `ft817_0`, `soapysdr_1
 |-------|------|---------|-------------|
 | `enabled` | bool | `false` | Enable Hamlib rigctl |
 | `listen` | ip | `127.0.0.1` | Bind address |
-| `port` | u16 | `4532` | Bind port |
+| `rig_ports` | table | `{}` | Remote name → local port; one listener each |
+
+One listener is started per `rig_ports` entry, each routing to its rig, so
+`rig_ports` must name at least one remote when the frontend is enabled. The
+older single `port` key and `--rigctl-port` are ignored.

 #### `[frontends.http_json]`

@@ -271,13 +382,17 @@ Rigs without an explicit `id` get auto-generated IDs like `ft817_0`, `soapysdr_1
 | `listen` | ip | `127.0.0.1` | Bind address |
 | `port` | u16 | `0` | Bind port (0 = ephemeral) |
 | `auth.tokens` | string[] | `[]` | Allowed auth tokens |
+| `auth.tokens_file` | string | — | Read tokens from this file, one per line |

 #### `[frontends.audio]`

 | Field | Type | Default | Description |
 |-------|------|---------|-------------|
 | `enabled` | bool | `true` | Enable audio client |
-| `server_port` | u16 | `4531` | Server audio port |
+| `server_url` | string | — | Audio endpoint for every remote |
+| `rig_urls` | table | `{}` | Remote name → audio URL (wins over `server_url`) |
+| `server_port` | u16 | `4531` | Fallback port when no URL is configured |
+| `rig_ports` | table | `{}` | Remote name → port; superseded by `rig_urls` |
 | `bridge.enabled` | bool | `false` | Enable local CPAL audio bridge |
 | `bridge.rx_output_device` | string | — | Local playback device |
 | `bridge.tx_input_device` | string | — | Local capture device |
@@ -287,16 +402,78 @@ Rigs without an explicit `id` get auto-generated IDs like `ft817_0`, `soapysdr_1
 The bridge is intended for WSJT-X integration via virtual audio devices (ALSA
 loopback on Linux, BlackHole on macOS).

+### Spectrum over a slow link
+
+Spectrum dominates the server↔client connection: everything else is a few
+hundred bytes, a frame is a few kilobytes. Three things govern what it costs.
+
+**Frames are pushed, not polled.** The client subscribes and the server sends
+frames at `[sdr].spectrum_interval_ms`. Polling cost a round trip per frame, so
+the rate was capped at 1/RTT — on a 200 ms link you could not exceed 5 frames a
+second however often the client asked. Clients fall back to polling
+automatically against a server too old to stream.
+
+**Bins travel as whole dBFS.** They are base64-encoded `i8` on the wire, about
+an eighth of the JSON array of floats they used to be, at the resolution the
+display draws anyway.
+
+**Both ends have a rate, and the slower one wins.** The server pushes no faster
+than `[sdr].spectrum_interval_ms`; the client asks for no more than
+`[[remotes]].spectrum_interval_ms`.
+
+For a link that struggles, start here:
+
+```toml
+[trx-server.sdr]
+spectrum_fft_size = 512      # half the bins, half the bytes
+spectrum_interval_ms = 200   # 5 frames/s instead of 20
+
+[[trx-client.remotes]]
+name = "remote-site"
+url = "radio.example.com:4530"
+spectrum_interval_ms = 200
+```
+
+That is roughly 0.7 KB per frame at 5 frames/s — about 3.5 KB/s, against
+roughly 200 KB/s for 1024 float bins at 20 frames/s.
+
 ### CLI Override Summary

 **trx-server:**
-`--config`, `--print-config`, `--rig`, `--access`, `--callsign`, `--listen`,
-`--port`. SDR options are file-only.
+`--config`, `--print-config`, `--check-config`, `--strict-config`, `--rig`,
+`--access`, `--callsign`, `--listen`, `--port`. SDR options are file-only.

 **trx-client:**
-`--config`, `--print-config`, `--url`, `--token`, `--poll-interval`,
-`--frontend`, `--http-listen`, `--http-port`, `--rigctl-listen`,
-`--rigctl-port`, `--http-json-listen`, `--http-json-port`, `--callsign`.
+`--config`, `--print-config`, `--check-config`, `--strict-config`, `--url`,
+`--token`, `--poll-interval`, `--rig-id`, `--frontend`, `--http-listen`,
+`--http-port`, `--rigctl-listen`, `--http-json-listen`, `--http-json-port`,
+`--callsign`.
+
+`--listen` on the server overrides the bind address of both the control
+listener and every rig's audio listener.
+
+---
+
+## Multiple Rigs in the Web UI
+
+A client connected to several rigs decodes all of them at once, whichever one
+is on screen. The rig picker in the header decides which rig the UI is about,
+and each page answers that differently:
+
+| Page | Shows |
+|------|-------|
+| Radio | The selected rig: its spectrum, its audio, and the mini decode views over the waterfall. |
+| Digital Modes | The selected rig: every decoder panel, its counts and its status line. |
+| Map | The whole station — every rig's positions, with the map's own rig filter to narrow it. |
+| Statistics | The whole station, including the per-rig comparison. |
+
+Switching rigs repaints the radio and digital modes pages for the rig now
+selected. Nothing is lost by switching: the traffic other rigs heard is still
+held, and switching back brings it up again. The one exception is the CW pane,
+which is a single running stream of copied text rather than a list of frames,
+so it starts empty on the rig you switch to.
+
+Each browser tab keeps its own selection, so two tabs can watch two rigs.

 ---

@@ -9,9 +9,5 @@ edition = "2021"
 license = "GPL-2.0-or-later"

 [dependencies]
-serde = { workspace = true }
-toml = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true }
-dirs = "6"
-thiserror = "2"
@@ -1,88 +0,0 @@
-// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
-//
-// SPDX-License-Identifier: GPL-2.0-or-later
-
-use serde::de::DeserializeOwned;
-use std::path::{Path, PathBuf};
-use thiserror::Error;
-
-#[derive(Debug, Error)]
-pub enum ConfigError {
-    #[error("Failed to read config file {0}: {1}")]
-    ReadError(PathBuf, String),
-
-    #[error("Failed to parse config file {0}: {1}")]
-    ParseError(PathBuf, String),
-}
-
-/// Returns the default search paths for `trx-rs.toml`
-/// (current directory → XDG config → /etc).
-fn config_search_paths() -> Vec<PathBuf> {
-    let mut paths = vec![PathBuf::from("trx-rs.toml")];
-    if let Some(config_dir) = dirs::config_dir() {
-        paths.push(config_dir.join("trx-rs").join("trx-rs.toml"));
-    }
-    paths.push(PathBuf::from("/etc/trx-rs/trx-rs.toml"));
-    paths
-}
-
-/// Extract and deserialize a named section from a TOML file.
-///
-/// Returns `Ok(Some(cfg))` when the section is present and parses cleanly,
-/// `Ok(None)` when the section is absent, or `Err` on I/O / parse failure.
-fn load_section_from_file<T: DeserializeOwned>(
-    path: &Path,
-    key: &str,
-) -> Result<Option<T>, ConfigError> {
-    let content = std::fs::read_to_string(path)
-        .map_err(|e| ConfigError::ReadError(path.to_path_buf(), e.to_string()))?;
-
-    let table: toml::Table = toml::from_str(&content)
-        .map_err(|e| ConfigError::ParseError(path.to_path_buf(), e.to_string()))?;
-
-    let Some(section) = table.get(key) else {
-        return Ok(None);
-    };
-
-    // Re-serialize the section then parse as T so all serde defaults apply.
-    let section_toml = toml::to_string(section)
-        .map_err(|e| ConfigError::ParseError(path.to_path_buf(), e.to_string()))?;
-    let cfg = toml::from_str::<T>(&section_toml)
-        .map_err(|e| ConfigError::ParseError(path.to_path_buf(), e.to_string()))?;
-    Ok(Some(cfg))
-}
-
-/// Trait for loading configuration from a `trx-rs.toml` section.
-pub trait ConfigFile: Sized + Default + DeserializeOwned {
-    /// Section key in `trx-rs.toml` (e.g. `"trx-server"` or `"trx-client"`).
-    fn section_key() -> &'static str;
-
-    /// Load the section from a specific file path.
-    ///
-    /// Returns an error if the file cannot be read, is not valid TOML, or
-    /// does not contain the expected `[<section_key>]` header.
-    fn load_from_file(path: &Path) -> Result<Self, ConfigError> {
-        load_section_from_file::<Self>(path, Self::section_key())?.ok_or_else(|| {
-            ConfigError::ParseError(
-                path.to_path_buf(),
-                format!("missing [{}] section", Self::section_key()),
-            )
-        })
-    }
-
-    /// Search default paths (`trx-rs.toml` in CWD → XDG → /etc) and load
-    /// the first file that contains the expected section.
-    ///
-    /// Returns `(config, path_where_found)` or `(Default::default(), None)`
-    /// when no config file is found.
-    fn load_from_default_paths() -> Result<(Self, Option<PathBuf>), ConfigError> {
-        for path in config_search_paths() {
-            if path.exists() {
-                if let Some(cfg) = load_section_from_file::<Self>(&path, Self::section_key())? {
-                    return Ok((cfg, Some(path)));
-                }
-            }
-        }
-        Ok((Self::default(), None))
-    }
-}
@@ -2,12 +2,12 @@
 //
 // SPDX-License-Identifier: GPL-2.0-or-later

-pub mod config;
+//! Shared application helpers.
+//!
+//! Configuration types and their loader live in the `trx-config` crate.
+
 pub mod logging;
-pub mod shared_config;
 pub mod util;

-pub use config::{ConfigError, ConfigFile};
 pub use logging::init_logging;
-pub use shared_config::{validate_log_level, validate_tokens};
 pub use util::normalize_name;
@@ -21,6 +21,7 @@ uuid = { workspace = true }
 cpal = "0.15"
 opus = "0.3"
 trx-app = { path = "../trx-app" }
+trx-config = { path = "../trx-config" }
 trx-core = { path = "../trx-core" }
 trx-protocol = { path = "../trx-protocol" }
 trx-frontend = { path = "trx-frontend" }
@@ -20,6 +20,7 @@ use tokio::task::JoinHandle;
 use tracing::{error, info};

 use trx_app::{init_logging, normalize_name};
+use trx_config::ConfigFile;
 use trx_core::audio::AudioStreamInfo;

 use trx_core::decode::DecodedMessage;
@@ -50,6 +51,12 @@ struct Cli {
    /// Print example configuration and exit
    #[arg(long = "print-config")]
    print_config: bool,
+    /// Treat unknown configuration keys as a fatal error
+    #[arg(long = "strict-config")]
+    strict_config: bool,
+    /// Validate the configuration and exit without starting anything
+    #[arg(long = "check-config")]
+    check_config: bool,
    /// Remote server URL (host:port)
    #[arg(short = 'u', long = "url")]
    url: Option<String>,
@@ -74,7 +81,7 @@ struct Cli {
    /// rigctl frontend listen address
    #[arg(long = "rigctl-listen")]
    rigctl_listen: Option<IpAddr>,
-    /// rigctl frontend listen port
+    /// Deprecated: ignored, use [frontends.rigctl].rig_ports
    #[arg(long = "rigctl-port")]
    rigctl_port: Option<u16>,
    /// JSON TCP frontend listen address
@@ -109,6 +116,65 @@ async fn main() -> DynResult<()> {
    Ok(())
 }

+/// `--check-config`: report everything wrong with the configuration and exit.
+///
+/// Unlike startup, this reports every problem it finds rather than stopping at
+/// the first, so a config can be fixed in one pass.  The file is checked as
+/// written, without CLI overrides.
+fn check_config(loaded: &trx_config::ConfigLoad<ClientConfig>) -> DynResult<()> {
+    match &loaded.path {
+        Some(path) => println!("{}", path.display()),
+        None => println!("(no config file found; checking built-in defaults)"),
+    }
+
+    let mut warnings: Vec<String> = loaded.unknown_keys.iter().map(|k| k.to_string()).collect();
+    warnings.extend(ClientConfig::deprecations(&loaded.present_keys));
+
+    let mut cfg = loaded.config.clone();
+    let mut errors = Vec::new();
+    if let Err(e) = cfg.resolve_secrets(loaded.path.as_deref()) {
+        errors.push(e);
+    }
+    let cfg = &cfg;
+    let remotes = cfg.resolved_remotes();
+    if remotes.is_empty() {
+        warnings.push(
+            "no remotes configured; --url will be required at startup (add [[remotes]] entries)"
+                .to_string(),
+        );
+    }
+
+    errors.extend(cfg.validate_all());
+    if !remotes.is_empty() {
+        errors.extend(cfg.validate_resolved_all(&remotes));
+    }
+
+    for w in &warnings {
+        println!("  warning: {}", w);
+    }
+    for e in &errors {
+        println!("  error: {}", e);
+    }
+
+    if errors.is_empty() {
+        println!(
+            "  OK: {} remote(s) configured: {}",
+            remotes.len(),
+            remotes
+                .iter()
+                .map(|r| r.name.as_str())
+                .collect::<Vec<_>>()
+                .join(", ")
+        );
+        if !warnings.is_empty() {
+            println!("  {} warning(s)", warnings.len());
+        }
+        Ok(())
+    } else {
+        Err(format!("{} error(s), {} warning(s)", errors.len(), warnings.len()).into())
+    }
+}
+
 /// Holds the state needed after async initialization completes.
 struct AppState {
    shutdown_tx: watch::Sender<bool>,
@@ -135,20 +201,44 @@ async fn async_init() -> DynResult<AppState> {
        std::process::exit(0);
    }

-    let (cfg, config_path) = if let Some(ref path) = cli.config {
-        let cfg = ClientConfig::load_from_file(path)?;
-        (cfg, Some(path.clone()))
+    let loaded = if let Some(ref path) = cli.config {
+        ClientConfig::load_from_file(path)?
    } else {
        ClientConfig::load_from_default_paths()?
    };
-    cfg.validate()
-        .map_err(|e| format!("Invalid client configuration: {}", e))?;
+    let config_path = loaded.path.clone();

-    init_logging(cfg.general.log_level.as_deref());
+    if cli.check_config {
+        match check_config(&loaded) {
+            Ok(()) => std::process::exit(0),
+            Err(e) => {
+                eprintln!("{}", e);
+                std::process::exit(1);
+            }
+        }
+    }
+
+    // Logging comes up before any config complaint so the warnings are visible.
+    init_logging(loaded.config.general.log_level.as_deref());

    if let Some(ref path) = config_path {
        info!("Loaded configuration from {}", path.display());
    }
+    loaded.report_unknown_keys(cli.strict_config)?;
+    loaded.report_deprecations();
+    if cli.rigctl_port.is_some() {
+        tracing::warn!(
+            "--rigctl-port is ignored; give each rig its own listener via \
+             [frontends.rigctl].rig_ports"
+        );
+    }
+
+    let mut cfg = loaded.config;
+    // Secrets configured as *_file are read before validation, so everything
+    // downstream sees resolved values.
+    cfg.resolve_secrets(config_path.as_deref())?;
+    cfg.validate()
+        .map_err(|e| format!("Invalid client configuration: {}", e))?;

    frontend_runtime.http_auth.tokens = cfg
        .frontends
@@ -198,10 +288,14 @@ async fn async_init() -> DynResult<AppState> {
        let token = cli.token.clone().or_else(|| cfg.remote.auth.token.clone());
        let poll_interval_ms = cli.poll_interval_ms.unwrap_or(cfg.remote.poll_interval_ms);
        vec![RemoteEntry {
+            spectrum_interval_ms: cfg.remote.spectrum_interval_ms,
            name,
            url: url.clone(),
            rig_id,
-            auth: config::RemoteAuthConfig { token },
+            auth: config::RemoteAuthConfig {
+                token,
+                token_file: None,
+            },
            poll_interval_ms,
        }]
    } else {
@@ -262,6 +356,30 @@ async fn async_init() -> DynResult<AppState> {
        .http_json_listen
        .unwrap_or(cfg.frontends.http_json.listen);
    let http_json_port = cli.http_json_port.unwrap_or(cfg.frontends.http_json.port);
+
+    // Fold the CLI overrides back into the config so validation and the
+    // frontends agree on what is about to be bound.
+    cfg.frontends.http.enabled = frontends.iter().any(|f| f == "http");
+    cfg.frontends.rigctl.enabled = frontends.iter().any(|f| f == "rigctl");
+    cfg.frontends.http_json.enabled = frontends.iter().any(|f| f == "httpjson");
+    cfg.frontends.http.listen = http_listen;
+    cfg.frontends.http.port = http_port;
+    cfg.frontends.rigctl.listen = rigctl_listen;
+    cfg.frontends.http_json.listen = http_json_listen;
+    cfg.frontends.http_json.port = http_json_port;
+
+    // Second validation phase: the per-rig maps are keyed by remote short name,
+    // so they can only be checked once the remote list is final.
+    if cli.url.is_none() {
+        cfg.validate_resolved(&resolved_remotes)
+            .map_err(|e| format!("Invalid client configuration: {}", e))?;
+    } else {
+        // --url replaces the configured remotes outright, so only the socket
+        // checks still apply.
+        trx_config::shared::check_socket_conflicts(&cfg.bound_sockets())
+            .map_err(|e| format!("Invalid client configuration: {}", e))?;
+    }
+
    let callsign = cli
        .callsign
        .clone()
@@ -366,6 +484,13 @@ async fn async_init() -> DynResult<AppState> {
            .map(|e| e.poll_interval_ms)
            .min()
            .unwrap_or(750);
+        // Entries sharing a server share its connections, so the most frequent
+        // request wins: whoever wants spectrum fastest sets the rate.
+        let spectrum_interval = entries
+            .iter()
+            .map(|e| e.spectrum_interval_ms)
+            .min()
+            .unwrap_or_else(|| remote_client::DEFAULT_SPECTRUM_INTERVAL.as_millis() as u64);

        let (server_tx, server_rx) = mpsc::channel::<RigRequest>(RIG_TASK_CHANNEL_BUFFER);
        for entry in entries {
@@ -379,6 +504,8 @@ async fn async_init() -> DynResult<AppState> {
            known_rigs: frontend_runtime.routing.remote_rigs.clone(),
            rig_states: frontend_runtime.routing.rig_states.clone(),
            poll_interval: Duration::from_millis(poll_interval),
+            spectrum_interval: Duration::from_millis(spectrum_interval),
+            spectrum_stream_unsupported: Arc::new(std::sync::atomic::AtomicBool::new(false)),
            spectrum: frontend_runtime.spectrum.sender.clone(),
            rig_spectrums: frontend_runtime.spectrum.per_rig.clone(),
            server_connected: frontend_runtime.routing.server_connected.clone(),
@@ -20,35 +20,22 @@ use trx_core::{RigError, RigResult};
 use trx_frontend::{RemoteRigEntry, SharedSpectrum};
 use trx_protocol::rig_command_to_client;
 use trx_protocol::types::RigEntry;
-use trx_protocol::{ClientCommand, ClientEnvelope, ClientResponse, MeterUpdate};
+use trx_protocol::{ClientCommand, ClientEnvelope, ClientResponse, MeterUpdate, SpectrumFrame};
+
+// Endpoint parsing lives in `trx-config` so config validation and the
+// connection code agree on what a URL means.
+pub use trx_config::url::{parse_audio_url, parse_remote_url, RemoteEndpoint};

-const DEFAULT_REMOTE_PORT: u16 = 4530;
-const DEFAULT_AUDIO_PORT: u16 = 4531;
 const CONNECT_TIMEOUT: Duration = Duration::from_secs(5);
 const IO_TIMEOUT: Duration = Duration::from_secs(15);
 const SPECTRUM_IO_TIMEOUT: Duration = Duration::from_secs(3);
 const MAX_JSON_LINE_BYTES: usize = 256 * 1024;
 const MAX_CONSECUTIVE_POLL_FAILURES: u32 = 3;

-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct RemoteEndpoint {
-    pub host: String,
-    pub port: u16,
-}
-
-impl RemoteEndpoint {
-    pub fn connect_addr(&self) -> String {
-        if self.host.contains(':') && !self.host.starts_with('[') {
-            format!("[{}]:{}", self.host, self.port)
-        } else {
-            format!("{}:{}", self.host, self.port)
-        }
-    }
-}
-
-// Keep remote spectrum reasonably responsive without returning to the old
-// timeout churn caused by a much tighter request cadence.
-const SPECTRUM_POLL_INTERVAL: Duration = Duration::from_millis(50);
+// Default spectrum cadence when a config does not specify one.  Both the push
+// stream and the poll fallback run at the configured rate; see
+// `[[remotes]].spectrum_interval_ms`.
+pub const DEFAULT_SPECTRUM_INTERVAL: Duration = Duration::from_millis(50);

 #[derive(Clone)]
 pub struct RemoteClientConfig {
@@ -57,6 +44,12 @@ pub struct RemoteClientConfig {
    pub selected_rig_id: Arc<Mutex<Option<String>>>,
    pub known_rigs: Arc<Mutex<Vec<RemoteRigEntry>>>,
    pub poll_interval: Duration,
+    /// How often spectrum frames are wanted.  Drives the poll fallback and is
+    /// the rate the client asks the server to push at.
+    pub spectrum_interval: Duration,
+    /// Set once a server has rejected `SubscribeSpectrum`, so later
+    /// connections to it go straight to polling instead of asking again.
+    pub spectrum_stream_unsupported: Arc<AtomicBool>,
    /// Spectrum watch sender; spectrum task publishes here, SSE clients subscribe.
    pub spectrum: Arc<watch::Sender<SharedSpectrum>>,
    /// Shared flag: `true` while a TCP connection to trx-server is active.
@@ -505,6 +498,100 @@ async fn send_get_sat_passes_on(
    ))
 }

+/// What ended a spectrum stream attempt.
+enum SpectrumStreamOutcome {
+    /// The stream ran and is over; the connection is spent.
+    Finished,
+    /// The server rejected the subscription.  The connection is still usable,
+    /// so the caller can poll on it.
+    Unsupported,
+}
+
+/// Subscribe to the server's spectrum push for one rig and publish frames as
+/// they arrive.
+///
+/// The server answers either with frames or, when it is too old to know the
+/// command, with an error response — which leaves the connection usable for
+/// polling, so falling back costs no reconnect.
+async fn run_spectrum_stream(
+    config: &RemoteClientConfig,
+    writer: &mut (impl AsyncWriteExt + Unpin),
+    reader: &mut (impl AsyncBufRead + Unpin),
+    short_name: &str,
+    shutdown_rx: &mut watch::Receiver<bool>,
+) -> RigResult<SpectrumStreamOutcome> {
+    let envelope = build_envelope(
+        config,
+        ClientCommand::SubscribeSpectrum,
+        Some(short_name.to_string()),
+    );
+    let mut payload = serde_json::to_string(&envelope)
+        .map_err(|e| RigError::communication(format!("JSON serialize failed: {e}")))?;
+    payload.push('\n');
+    time::timeout(SPECTRUM_IO_TIMEOUT, writer.write_all(payload.as_bytes()))
+        .await
+        .map_err(|_| RigError::communication("spectrum subscribe write timed out".to_string()))?
+        .map_err(|e| RigError::communication(format!("spectrum subscribe write failed: {e}")))?;
+    time::timeout(SPECTRUM_IO_TIMEOUT, writer.flush())
+        .await
+        .map_err(|_| RigError::communication("spectrum subscribe flush timed out".to_string()))?
+        .map_err(|e| RigError::communication(format!("spectrum subscribe flush failed: {e}")))?;
+
+    // Re-check what the UI wants: switching rigs has to end this stream so the
+    // connection can be rebuilt for the new one.
+    let mut supervisor = time::interval(Duration::from_millis(500));
+    supervisor.tick().await;
+
+    loop {
+        tokio::select! {
+            changed = shutdown_rx.changed() => {
+                match changed {
+                    Ok(()) if *shutdown_rx.borrow() => return Ok(SpectrumStreamOutcome::Finished),
+                    Ok(()) => {}
+                    Err(_) => return Ok(SpectrumStreamOutcome::Finished),
+                }
+            }
+            _ = supervisor.tick() => {
+                let wanted = active_spectrum_rig_ids(config);
+                if wanted.len() != 1 || wanted[0] != short_name {
+                    return Ok(SpectrumStreamOutcome::Finished);
+                }
+            }
+            line = read_limited_line(reader, MAX_JSON_LINE_BYTES) => {
+                let line = line
+                    .map_err(|e| RigError::communication(format!("spectrum read failed: {e}")))?
+                    .ok_or_else(|| {
+                        RigError::communication("spectrum connection closed".to_string())
+                    })?;
+                let trimmed = line.trim_end();
+                if trimmed.is_empty() {
+                    continue;
+                }
+                match serde_json::from_str::<SpectrumFrame>(trimmed) {
+                    Ok(frame) => publish_spectrum_frame(config, short_name, frame),
+                    // Anything that is not a frame means the server would rather
+                    // answer than stream: an older build rejecting the command.
+                    Err(_) => return Ok(SpectrumStreamOutcome::Unsupported),
+                }
+            }
+        }
+    }
+}
+
+/// Publish one pushed frame to the per-rig and selected-rig watch channels.
+fn publish_spectrum_frame(config: &RemoteClientConfig, short_name: &str, frame: SpectrumFrame) {
+    if let Ok(map) = config.rig_spectrums.read() {
+        if let Some(tx) = map.get(short_name) {
+            tx.send_modify(|s| s.set(Some(frame.spectrum.clone()), frame.vchan_rds.clone()));
+        }
+    }
+    if selected_rig_id(config).as_deref() == Some(short_name) {
+        config
+            .spectrum
+            .send_modify(|s| s.set(Some(frame.spectrum), frame.vchan_rds));
+    }
+}
+
 async fn handle_spectrum_connection(
    config: &RemoteClientConfig,
    stream: TcpStream,
@@ -512,7 +599,33 @@ async fn handle_spectrum_connection(
 ) -> RigResult<()> {
    let (reader, mut writer) = stream.into_split();
    let mut reader = BufReader::new(reader);
-    let mut interval = time::interval(SPECTRUM_POLL_INTERVAL);
+
+    // Prefer the push stream: polling costs a round trip per frame, so on a
+    // high-latency link the frame rate is 1/RTT no matter what interval is
+    // configured.  It only works for one rig per connection, and only against
+    // a server new enough to understand the command.
+    let streamable = active_spectrum_rig_ids(config);
+    if streamable.len() == 1 && !config.spectrum_stream_unsupported.load(Ordering::Relaxed) {
+        match run_spectrum_stream(
+            config,
+            &mut writer,
+            &mut reader,
+            &streamable[0],
+            shutdown_rx,
+        )
+        .await?
+        {
+            SpectrumStreamOutcome::Finished => return Ok(()),
+            SpectrumStreamOutcome::Unsupported => {
+                info!("Server does not support spectrum streaming; falling back to polling");
+                config
+                    .spectrum_stream_unsupported
+                    .store(true, Ordering::Relaxed);
+            }
+        }
+    }
+
+    let mut interval = time::interval(config.spectrum_interval);
    // Cache the token outside the poll loop to avoid cloning it every 50ms.
    let cached_token = config.token.clone();

@@ -1195,92 +1308,13 @@ async fn read_limited_line<R: AsyncBufRead + Unpin>(
    }
 }

-pub fn parse_remote_url(url: &str) -> Result<RemoteEndpoint, String> {
-    parse_endpoint_url(url, DEFAULT_REMOTE_PORT, "remote")
-}
-
-pub fn parse_audio_url(url: &str) -> Result<RemoteEndpoint, String> {
-    parse_endpoint_url(url, DEFAULT_AUDIO_PORT, "audio")
-}
-
-fn parse_endpoint_url(url: &str, default_port: u16, kind: &str) -> Result<RemoteEndpoint, String> {
-    let trimmed = url.trim();
-    if trimmed.is_empty() {
-        return Err(format!("{kind} url is empty"));
-    }
-
-    let addr = trimmed
-        .strip_prefix("tcp://")
-        .or_else(|| trimmed.strip_prefix("http-json://"))
-        .or_else(|| trimmed.strip_prefix("audio://"))
-        .unwrap_or(trimmed);
-
-    parse_host_port(addr, default_port, kind)
-}
-
-fn parse_host_port(input: &str, default_port: u16, kind: &str) -> Result<RemoteEndpoint, String> {
-    if let Some(rest) = input.strip_prefix('[') {
-        let closing = rest
-            .find(']')
-            .ok_or_else(|| format!("invalid {kind} url: missing closing ']' for IPv6 host"))?;
-        let host = &rest[..closing];
-        let remainder = &rest[closing + 1..];
-        if host.is_empty() {
-            return Err(format!("invalid {kind} url: host is empty"));
-        }
-        let port = if remainder.is_empty() {
-            default_port
-        } else if let Some(port_str) = remainder.strip_prefix(':') {
-            parse_port(port_str, kind)?
-        } else {
-            return Err(format!("invalid {kind} url: expected ':<port>' after ']'"));
-        };
-        return Ok(RemoteEndpoint {
-            host: host.to_string(),
-            port,
-        });
-    }
-
-    if input.contains(':') {
-        if input.matches(':').count() > 1 {
-            return Err(format!(
-                "invalid {kind} url: IPv6 host must be bracketed like [::1]:4532"
-            ));
-        }
-        let (host, port_str) = input
-            .rsplit_once(':')
-            .ok_or_else(|| format!("invalid {kind} url: expected host:port"))?;
-        if host.is_empty() {
-            return Err(format!("invalid {kind} url: host is empty"));
-        }
-        return Ok(RemoteEndpoint {
-            host: host.to_string(),
-            port: parse_port(port_str, kind)?,
-        });
-    }
-
-    Ok(RemoteEndpoint {
-        host: input.to_string(),
-        port: default_port,
-    })
-}
-
-fn parse_port(port_str: &str, kind: &str) -> Result<u16, String> {
-    let port: u16 = port_str
-        .parse()
-        .map_err(|_| format!("invalid {kind} port: '{port_str}'"))?;
-    if port == 0 {
-        return Err(format!("invalid {kind} port: 0"));
-    }
-    Ok(port)
-}
-
 #[cfg(test)]
 mod tests {
    #[allow(unused_imports)]
    use super::{has_short_names, resolve_server_rig_id, resolve_short_name};
    use super::{
        parse_audio_url, parse_remote_url, RemoteClientConfig, RemoteEndpoint, SharedSpectrum,
+        DEFAULT_SPECTRUM_INTERVAL,
    };
    use std::collections::HashMap;
    use std::sync::atomic::AtomicBool;
@@ -1475,6 +1509,8 @@ mod tests {
                selected_rig_id: Arc::new(Mutex::new(None)),
                known_rigs: Arc::new(Mutex::new(Vec::new())),
                poll_interval: Duration::from_millis(100),
+                spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+                spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
                spectrum: Arc::new(spectrum_tx),
                server_connected: Arc::new(AtomicBool::new(false)),
                rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
@@ -1520,6 +1556,8 @@ mod tests {
            selected_rig_id: Arc::new(Mutex::new(Some("sdr".to_string()))),
            known_rigs: Arc::new(Mutex::new(Vec::new())),
            poll_interval: Duration::from_millis(500),
+            spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+            spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
            spectrum: Arc::new(spectrum_tx),
            server_connected: Arc::new(AtomicBool::new(false)),
            rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
@@ -1535,6 +1573,130 @@ mod tests {
        assert_eq!(envelope.rig_id.as_deref(), Some("sdr"));
    }

+    fn stream_test_config(spectrum_tx: watch::Sender<SharedSpectrum>) -> super::RemoteClientConfig {
+        super::RemoteClientConfig {
+            addr: "127.0.0.1:4530".to_string(),
+            token: None,
+            selected_rig_id: Arc::new(Mutex::new(Some("sdr".to_string()))),
+            known_rigs: Arc::new(Mutex::new(Vec::new())),
+            poll_interval: Duration::from_millis(500),
+            spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+            spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
+            spectrum: Arc::new(spectrum_tx),
+            server_connected: Arc::new(AtomicBool::new(false)),
+            rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
+            rig_states: Arc::new(RwLock::new(HashMap::new())),
+            rig_spectrums: Arc::new(RwLock::new(HashMap::new())),
+            rig_id_to_short_name: HashMap::new(),
+            short_name_to_rig_id: Arc::new(RwLock::new(HashMap::new())),
+            sat_passes: Arc::new(RwLock::new(None)),
+            rig_meters: Arc::new(RwLock::new(HashMap::new())),
+        }
+    }
+
+    /// A pushed frame reaches the watch channel the UI reads, with no request
+    /// from the client beyond the initial subscribe.
+    #[tokio::test]
+    async fn spectrum_stream_publishes_pushed_frames() {
+        use tokio::io::{AsyncBufReadExt, BufReader};
+
+        let (spectrum_tx, mut spectrum_rx) = watch::channel(SharedSpectrum::default());
+        let config = stream_test_config(spectrum_tx);
+        let (shutdown_tx, mut shutdown_rx) = watch::channel(false);
+
+        let (client_io, mut server_io) = tokio::io::duplex(64 * 1024);
+        let (client_read, mut client_write) = tokio::io::split(client_io);
+        let mut client_read = BufReader::new(client_read);
+
+        let task = tokio::spawn(async move {
+            super::run_spectrum_stream(
+                &config,
+                &mut client_write,
+                &mut client_read,
+                "sdr",
+                &mut shutdown_rx,
+            )
+            .await
+        });
+
+        // The server sees the subscribe, then pushes without being asked.
+        let mut server = BufReader::new(&mut server_io);
+        let mut subscribe = String::new();
+        server.read_line(&mut subscribe).await.expect("subscribe");
+        assert!(
+            subscribe.contains("subscribe_spectrum"),
+            "unexpected command: {subscribe}"
+        );
+
+        let frame = trx_protocol::SpectrumFrame {
+            rig_id: "sdr".to_string(),
+            spectrum: trx_core::rig::state::SpectrumData {
+                bins: vec![-70.0, -30.0],
+                center_hz: 14_200_000,
+                sample_rate: 1_920_000,
+                rds: None,
+            },
+            vchan_rds: None,
+        };
+        let mut line = serde_json::to_string(&frame).unwrap();
+        line.push('\n');
+        server_io.write_all(line.as_bytes()).await.expect("push");
+        server_io.flush().await.expect("flush");
+
+        spectrum_rx.changed().await.expect("spectrum published");
+        let published = spectrum_rx.borrow().clone();
+        let spectrum = published.frame.expect("spectrum present");
+        assert_eq!(spectrum.center_hz, 14_200_000);
+        assert_eq!(spectrum.bins, vec![-70.0, -30.0]);
+
+        let _ = shutdown_tx.send(true);
+        let _ = task.await;
+    }
+
+    /// An older server answers the unknown command with an error instead of
+    /// frames.  That has to read as "poll instead", not as a dead connection.
+    #[tokio::test]
+    async fn spectrum_stream_falls_back_when_unsupported() {
+        use tokio::io::{AsyncBufReadExt, BufReader};
+
+        let (spectrum_tx, _spectrum_rx) = watch::channel(SharedSpectrum::default());
+        let config = stream_test_config(spectrum_tx);
+        let (_shutdown_tx, mut shutdown_rx) = watch::channel(false);
+
+        let (client_io, mut server_io) = tokio::io::duplex(64 * 1024);
+        let (client_read, mut client_write) = tokio::io::split(client_io);
+        let mut client_read = BufReader::new(client_read);
+
+        let task = tokio::spawn(async move {
+            super::run_spectrum_stream(
+                &config,
+                &mut client_write,
+                &mut client_read,
+                "sdr",
+                &mut shutdown_rx,
+            )
+            .await
+        });
+
+        let mut server = BufReader::new(&mut server_io);
+        let mut subscribe = String::new();
+        server.read_line(&mut subscribe).await.expect("subscribe");
+
+        server_io
+            .write_all(
+                b"{\"success\":false,\"state\":null,\"error\":\"Invalid JSON: unknown variant\"}\n",
+            )
+            .await
+            .expect("error response");
+        server_io.flush().await.expect("flush");
+
+        let outcome = task.await.expect("join").expect("stream result");
+        assert!(
+            matches!(outcome, super::SpectrumStreamOutcome::Unsupported),
+            "an error response should fall back to polling"
+        );
+    }
+
    #[test]
    fn build_envelope_translates_short_name_to_server_rig_id() {
        let (spectrum_tx, _spectrum_rx) = watch::channel(SharedSpectrum::default());
@@ -1548,6 +1710,8 @@ mod tests {
            selected_rig_id: Arc::new(Mutex::new(Some("home-hf".to_string()))),
            known_rigs: Arc::new(Mutex::new(Vec::new())),
            poll_interval: Duration::from_millis(500),
+            spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+            spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
            spectrum: Arc::new(spectrum_tx),
            server_connected: Arc::new(AtomicBool::new(false)),
            rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
@@ -1580,6 +1744,8 @@ mod tests {
            selected_rig_id: Arc::new(Mutex::new(None)),
            known_rigs: Arc::new(Mutex::new(Vec::new())),
            poll_interval: Duration::from_millis(500),
+            spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+            spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
            spectrum: Arc::new(spectrum_tx),
            server_connected: Arc::new(AtomicBool::new(false)),
            rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
@@ -1604,6 +1770,8 @@ mod tests {
            selected_rig_id: Arc::new(Mutex::new(None)),
            known_rigs: Arc::new(Mutex::new(Vec::new())),
            poll_interval: Duration::from_millis(500),
+            spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+            spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
            spectrum: Arc::new(spectrum_tx),
            server_connected: Arc::new(AtomicBool::new(false)),
            rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
@@ -1644,6 +1812,8 @@ mod tests {
            selected_rig_id: Arc::new(Mutex::new(None)),
            known_rigs: known_rigs.clone(),
            poll_interval: Duration::from_millis(500),
+            spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+            spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
            spectrum: Arc::new(spectrum_tx),
            server_connected: Arc::new(AtomicBool::new(false)),
            rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
@@ -1717,6 +1887,8 @@ mod tests {
            selected_rig_id,
            known_rigs,
            poll_interval: Duration::from_millis(500),
+            spectrum_interval: DEFAULT_SPECTRUM_INTERVAL,
+            spectrum_stream_unsupported: Arc::new(AtomicBool::new(false)),
            spectrum: Arc::new(spectrum_tx),
            server_connected: Arc::new(AtomicBool::new(false)),
            rig_server_connected: Arc::new(RwLock::new(HashMap::new())),
@@ -1,3 +1,7 @@
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore,
  hostState
@@ -140,18 +144,22 @@ function aisLatestByVessel(messages) {
  }
  return Array.from(byMmsi.values());
 }
+function aisRigMessages() {
+  return forActiveRig(aisMessageHistory);
+}
 function updateAisSummary() {
  const plan = currentAisChannelPlan();
  if (aisChannelSummaryEl) {
    aisChannelSummaryEl.textContent = `A ${formatAisMhz(plan.aHz)} · B ${formatAisMhz(plan.bHz)}`;
  }
-  const vessels = aisLatestByVessel(aisMessageHistory);
+  const rigMessages = aisRigMessages();
+  const vessels = aisLatestByVessel(rigMessages);
  if (aisVesselCountEl) {
    const count = vessels.length;
    aisVesselCountEl.textContent = `${count} vessel${count === 1 ? "" : "s"}`;
  }
  if (aisLatestSeenEl) {
-    const latest = aisMessageHistory[0];
+    const latest = rigMessages[0];
    if (!latest) {
      aisLatestSeenEl.textContent = "No traffic yet";
    } else {
@@ -222,7 +230,9 @@ function updateAisBar() {
  updateAisSummary();
  const isAis = (document.getElementById("mode")?.value || "").toUpperCase() === "AIS";
  const cutoffMs = Date.now() - AIS_BAR_WINDOW_MS;
-  const recent = aisMessageHistory.filter((msg) => (msg._tsMs ?? 0) >= cutoffMs);
+  const recent = aisMessageHistory.filter(
+    (msg) => (msg._tsMs ?? 0) >= cutoffMs && isActiveRigDecode(msg.rig_id)
+  );
  const messages = aisLatestByVessel(recent).slice(0, 8);
  if (!isAis || messages.length === 0) {
    aisBarOverlay.style.display = "none";
@@ -267,7 +277,7 @@ function renderAisHistory() {
    return;
  }
  const fragment = document.createDocumentFragment();
-  for (const message of aisMessageHistory) {
+  for (const message of aisRigMessages()) {
    fragment.appendChild(renderAisRow(message));
  }
  aisMessagesEl.replaceChildren(fragment);
@@ -299,10 +309,10 @@ function normalizeServerAisMessage(msg) {
 }
 function onServerAisBatch(messages) {
  if (!Array.isArray(messages) || messages.length === 0) return;
-  if (aisStatus) aisStatus.textContent = "Receiving";
  const normalized = [];
  for (const msg of messages) {
    const next = normalizeServerAisMessage(msg);
+    if (aisStatus && isActiveRigDecode(next.rig_id)) aisStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], {
@@ -342,8 +352,9 @@ if (aisFilterInput) {
  });
 }
 function onServerAis(msg) {
-  if (aisStatus) aisStatus.textContent = "Receiving";
-  addAisMessage(normalizeServerAisMessage(msg));
+  const message = normalizeServerAisMessage(msg);
+  if (aisStatus && isActiveRigDecode(message.rig_id)) aisStatus.textContent = "Receiving";
+  addAisMessage(message);
 }
 updateAisSummary();
 window.trxPluginRuntime.registerDecoder({
@@ -353,6 +364,10 @@ window.trxPluginRuntime.registerDecoder({
  restore: onServerAisBatch,
  reset: resetAisHistoryView,
  prune: pruneAisHistoryView,
+  rerender: () => {
+    updateAisBar();
+    renderAisHistory();
+  },
  // Oldest first, so vessel tracks are rebuilt in the order they happened.
  syncMap: () => {
    for (const entry of [...aisMessageHistory].reverse()) plotAisMessage(entry);
@@ -1065,6 +1065,9 @@ var runtime = {
    plugin.prune();
    return true;
  },
+  rerenderAll() {
+    for (const plugin of decoders.values()) plugin.rerender?.();
+  },
  syncMapAll() {
    for (const plugin of decoders.values()) plugin.syncMap?.();
  },
@@ -3555,6 +3558,13 @@ function positionRdsPsOverlay() {
 function resetRdsDisplay() {
  updateRdsPsOverlay(primaryRds);
 }
+function refreshDecodeBars() {
+  window.updateAisBar?.();
+  window.updateVdesBar?.();
+  window.updateAprsBar?.();
+  window.updateFt8Bar?.();
+  window.updateCwBar?.();
+}
 function resetDecoderStateOnRigSwitch() {
  primaryRds = null;
  vchanRdsById = /* @__PURE__ */ new Map();
@@ -3569,6 +3579,8 @@ function resetDecoderStateOnRigSwitch() {
    const el = document.getElementById(id);
    if (el) el.textContent = "--";
  });
+  refreshDecodeBars();
+  window.trxPluginRuntime.rerenderAll();
 }
 function resetWfmStereoIndicator() {
  if (!wfmStFlagEl) return;
@@ -4788,10 +4800,7 @@ function render(update) {
    const connText = _decodeConnectedText[d.id] || "Connected, listening for packets";
    setModeBoundDecodeStatus(el, d.active_modes, "Select " + d.active_modes[0] + " mode to decode", connText);
  }
-  if (window.updateAisBar) window.updateAisBar();
-  if (window.updateVdesBar) window.updateVdesBar();
-  if (window.updateAprsBar) window.updateAprsBar();
-  if (window.updateFt8Bar) window.updateFt8Bar();
+  refreshDecodeBars();
  for (const d of decoderRegistry) {
    if (d.activation !== "toggle") continue;
    const key = d.id.replace(/-/g, "_") + "_decode_enabled";
@@ -5,6 +5,10 @@ import {
  normalizeAprsPacket,
  renderAprsPacketRow
 } from "./chunk-OPEIVJGD.js";
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore,
  hostState
@@ -82,20 +86,25 @@ function aprsFilterMatch(pkt) {
  ].filter(Boolean).join(" ").toUpperCase();
  return haystack.includes(aprsFilterText);
 }
+function aprsRigPackets() {
+  return forActiveRig(aprsPacketHistory);
+}
 function aprsVisiblePackets() {
-  const packets = aprsCollapseDup ? collapseAprsDuplicates(aprsPacketHistory) : aprsPacketHistory;
+  const rigPackets = aprsRigPackets();
+  const packets = aprsCollapseDup ? collapseAprsDuplicates(rigPackets) : rigPackets;
  return packets.filter(aprsFilterMatch);
 }
 function updateAprsSummary() {
+  const rigPackets = aprsRigPackets();
  const visible = aprsVisiblePackets();
  if (aprsTotalCountEl) {
-    aprsTotalCountEl.textContent = `${aprsPacketHistory.length} total`;
+    aprsTotalCountEl.textContent = `${rigPackets.length} total`;
  }
  if (aprsVisibleCountEl) {
    aprsVisibleCountEl.textContent = `${visible.length} shown`;
  }
  if (aprsLatestSeenEl) {
-    const latest = aprsPacketHistory[0];
+    const latest = rigPackets[0];
    if (!latest) {
      aprsLatestSeenEl.textContent = "No packets yet";
    } else {
@@ -153,7 +162,9 @@ function updateAprsBar() {
  if (!aprsBarOverlay) return;
  const isPkt = (document.getElementById("mode")?.value || "").toUpperCase() === "PKT";
  const cutoffMs = Date.now() - APRS_BAR_WINDOW_MS;
-  const okFrames = aprsPacketHistory.filter((p) => p.crcOk && (p._tsMs ?? 0) >= cutoffMs);
+  const okFrames = aprsPacketHistory.filter(
+    (p) => p.crcOk && (p._tsMs ?? 0) >= cutoffMs && isActiveRigDecode(p.rig_id)
+  );
  const frames = collapseAprsDuplicates(okFrames).slice(0, 8);
  const newestTsMs = frames.reduce((latest, pkt) => Math.max(latest, Number(pkt._tsMs) || 0), 0);
  if (!isPkt || frames.length === 0 || newestTsMs <= aprsBarDismissedAtMs) {
@@ -215,11 +226,11 @@ function normalizeServerAprsPacket(pkt) {
 }
 function onServerAprsBatch(packets) {
  if (!Array.isArray(packets) || packets.length === 0) return;
-  if (aprsStatus) aprsStatus.textContent = "Receiving";
  const normalized = [];
  let hasCrcOk = false;
  for (const pkt of packets) {
    const next = normalizeServerAprsPacket(pkt);
+    if (aprsStatus && isActiveRigDecode(next.rig_id)) aprsStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], { hour: "2-digit", minute: "2-digit", second: "2-digit" });
@@ -277,8 +288,9 @@ if (aprsFilterInput) {
  });
 }
 function onServerAprs(pkt) {
-  if (aprsStatus) aprsStatus.textContent = "Receiving";
-  addAprsPacket(normalizeServerAprsPacket(pkt));
+  const packet = normalizeServerAprsPacket(pkt);
+  if (aprsStatus && isActiveRigDecode(packet.rig_id)) aprsStatus.textContent = "Receiving";
+  addAprsPacket(packet);
 }
 renderAprsHistory();
 window.trxPluginRuntime.registerDecoder({
@@ -288,6 +300,10 @@ window.trxPluginRuntime.registerDecoder({
  restore: onServerAprsBatch,
  reset: resetAprsHistoryView,
  prune: pruneAprsHistoryView,
+  rerender: () => {
+    updateAprsBar();
+    renderAprsHistory();
+  },
  // Oldest first, so station tracks are rebuilt in the order they happened.
  syncMap: () => {
    for (const entry of [...aprsPacketHistory].reverse()) plotAprsPacket(entry);
@@ -1,3 +1,7 @@
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore
 } from "./chunk-KL66PICH.js";
@@ -153,9 +157,10 @@ function initializeFtxDecoder(config) {
  const render = () => {
    prune();
    if (!messagesElement) return;
+    const rigMessages = forActiveRig(history);
    const fragment = document.createDocumentFragment();
    let count = 0;
-    for (const message of history) {
+    for (const message of rigMessages) {
      if (count >= 200) break;
      if (filterText && !(message.message ?? "").toUpperCase().includes(filterText)) continue;
      fragment.appendChild(renderRow(message));
@@ -177,6 +182,9 @@ function initializeFtxDecoder(config) {
      });
    }
    return {
+      // The rig that heard it, kept so the mini view can tell a decode of the
+      // rig on screen from one a background rig made on another band.
+      rig_id: message.rig_id ?? null,
      receiver: bridge.getDecodeRigMeta?.() ?? null,
      ts_ms: message.ts_ms,
      snr_db: message.snr_db,
@@ -188,7 +196,9 @@ function initializeFtxDecoder(config) {
  };
  const receiveBatch = (messages) => {
    if (messages.length === 0) return;
-    if (status) status.textContent = "Receiving";
+    if (status && messages.some((message) => isActiveRigDecode(message.rig_id))) {
+      status.textContent = "Receiving";
+    }
    history = messages.map(normalize).reverse().concat(history);
    prune();
    bridge.setFt8FamilyBarDecoder?.(id);
@@ -202,7 +212,7 @@ function initializeFtxDecoder(config) {
    bridge.clearMapMarkersByType?.(id);
  };
  const barFrames = () => {
-    const recent = history.filter((message) => (finiteNumber(message._tsMs ?? message.ts_ms) ?? 0) >= Date.now() - 9e5).slice(0, 8);
+    const recent = history.filter((message) => (finiteNumber(message._tsMs ?? message.ts_ms) ?? 0) >= Date.now() - 9e5 && isActiveRigDecode(message.rig_id)).slice(0, 8);
    let html = "";
    for (const message of recent) {
      const timestamp = finiteNumber(message._tsMs ?? message.ts_ms);
@@ -226,7 +236,11 @@ function initializeFtxDecoder(config) {
      prune();
      render();
    },
-    reset
+    reset,
+    rerender: () => {
+      bridge.updateFt8Bar?.();
+      render();
+    }
  });
  bridge.registerFt8FamilyBarRenderer?.(id, barFrames);
  const updatePeriod = () => {
@@ -0,0 +1,18 @@
+import {
+  hostState
+} from "./chunk-KL66PICH.js";
+
+// src/plugins/active-rig.ts
+function isActiveRigDecode(rigId) {
+  const activeRigId = hostState.lastActiveRigId;
+  if (!activeRigId || !rigId) return true;
+  return rigId === activeRigId;
+}
+function forActiveRig(items) {
+  return items.filter((item) => isActiveRigDecode(item.rig_id));
+}
+
+export {
+  isActiveRigDecode,
+  forActiveRig
+};
@@ -1,3 +1,6 @@
+import {
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore
 } from "./chunk-KL66PICH.js";
@@ -25,7 +28,7 @@ var CW_BAR_LINE_GAP_MS = 5e3;
 var cwLastAppendTime = 0;
 var cwTonePickerRaf = null;
 var cwBarHistory = [];
-var cwBarCurrentLine = null;
+var cwBarCurrentLines = /* @__PURE__ */ new Map();
 var cwBarDismissedAtMs = 0;
 var cwAutoLocalOverride = null;
 function escapeCwHtml(input) {
@@ -50,20 +53,22 @@ cwWindow.applyCwAutoUiFromServer = function(enabled) {
  if (cwAutoLocalOverride !== null) return;
  applyCwAutoUi(enabled);
 };
-function cwBarFlushCurrentLine() {
-  if (cwBarCurrentLine && cwBarCurrentLine.text.trim()) {
-    cwBarHistory.unshift(cwBarCurrentLine);
+function cwBarFlushCurrentLine(key) {
+  const line = cwBarCurrentLines.get(key);
+  cwBarCurrentLines.delete(key);
+  if (line?.text.trim()) {
+    cwBarHistory.unshift(line);
    if (cwBarHistory.length > 50) cwBarHistory.length = 50;
  }
-  cwBarCurrentLine = null;
 }
 function updateCwBar() {
  if (!cwBarOverlay) return;
  const mode = (document.getElementById("mode")?.value || "").toUpperCase();
  const isCw = mode === "CW" || mode === "CWR";
  const cutoffMs = Date.now() - CW_BAR_WINDOW_MS;
-  const recent = cwBarHistory.filter((l) => l.tsMs >= cutoffMs);
-  const liveLines = cwBarCurrentLine && cwBarCurrentLine.text ? [cwBarCurrentLine, ...recent] : recent;
+  const recent = cwBarHistory.filter((l) => l.tsMs >= cutoffMs && isActiveRigDecode(l.rigId));
+  const inProgress = [...cwBarCurrentLines.values()].filter((l) => l.text && isActiveRigDecode(l.rigId)).sort((a, b) => b.tsMs - a.tsMs);
+  const liveLines = [...inProgress, ...recent];
  const newestTsMs = liveLines.reduce((latest, line) => Math.max(latest, line.tsMs || 0), 0);
  if (!isCw || liveLines.length === 0 || newestTsMs <= cwBarDismissedAtMs) {
    cwBarOverlay.style.display = "none";
@@ -308,7 +313,7 @@ function resetCwHistoryView() {
  if (cwOutputEl) cwOutputEl.innerHTML = "";
  cwLastAppendTime = 0;
  cwBarHistory = [];
-  cwBarCurrentLine = null;
+  cwBarCurrentLines.clear();
  updateCwBar();
  drawCwTonePicker();
 }
@@ -324,8 +329,9 @@ document.getElementById("settings-clear-cw-history")?.addEventListener("click",
  })();
 });
 function onServerCw(evt) {
-  if (cwStatusEl) cwStatusEl.textContent = "Receiving";
-  if (evt.text && cwOutputEl) {
+  const forSelectedRig = isActiveRigDecode(evt.rig_id ?? null);
+  if (cwStatusEl && forSelectedRig) cwStatusEl.textContent = "Receiving";
+  if (evt.text && cwOutputEl && forSelectedRig) {
    const now = Date.now();
    if (!cwOutputEl.lastElementChild || now - cwLastAppendTime > 1e4 || evt.text === "\n") {
      const line = document.createElement("div");
@@ -346,25 +352,29 @@ function onServerCw(evt) {
  }
  if (evt.text) {
    const now = Date.now();
+    const rigId = evt.rig_id ?? null;
+    const key = rigId ?? "";
    if (evt.text === "\n") {
-      cwBarFlushCurrentLine();
+      cwBarFlushCurrentLine(key);
    } else {
-      if (!cwBarCurrentLine || now - cwBarCurrentLine.lastMs > CW_BAR_LINE_GAP_MS) {
-        cwBarFlushCurrentLine();
+      let line = cwBarCurrentLines.get(key);
+      if (!line || now - line.lastMs > CW_BAR_LINE_GAP_MS) {
+        cwBarFlushCurrentLine(key);
        const ts = new Date(now).toLocaleTimeString([], { hour: "2-digit", minute: "2-digit", second: "2-digit" });
-        cwBarCurrentLine = { tsMs: now, ts, text: "", wpm: null, tone_hz: null, lastMs: now };
+        line = { rigId, tsMs: now, ts, text: "", wpm: null, tone_hz: null, lastMs: now };
+        cwBarCurrentLines.set(key, line);
      }
-      cwBarCurrentLine.text += evt.text;
-      cwBarCurrentLine.lastMs = now;
-      if (Number.isFinite(Number(evt.wpm))) cwBarCurrentLine.wpm = clampCwWpm(evt.wpm);
-      if (Number.isFinite(Number(evt.tone_hz))) cwBarCurrentLine.tone_hz = Math.round(Number(evt.tone_hz));
+      line.text += evt.text;
+      line.lastMs = now;
+      if (Number.isFinite(Number(evt.wpm))) line.wpm = clampCwWpm(evt.wpm);
+      if (Number.isFinite(Number(evt.tone_hz))) line.tone_hz = Math.round(Number(evt.tone_hz));
    }
    updateCwBar();
  }
-  if (cwSignalIndicator) {
+  if (cwSignalIndicator && forSelectedRig) {
    cwSignalIndicator.className = evt.signal_on ? "cw-signal-on" : "cw-signal-off";
  }
-  if (!cwAutoInput || cwAutoInput.checked) {
+  if (forSelectedRig && (!cwAutoInput || cwAutoInput.checked)) {
    if (cwWpmInput && Number.isFinite(Number(evt.wpm))) {
      cwWpmInput.value = String(clampCwWpm(evt.wpm));
    }
@@ -389,7 +399,14 @@ cwWindow.trxPluginRuntime.registerDecoder({
  id: "cw",
  onMessage: onServerCw,
  restore: restoreCwHistory,
-  reset: resetCwHistoryView
+  reset: resetCwHistoryView,
+  // The copied text of a rig that is no longer on screen cannot be unpicked
+  // from the pane, so the switch starts the new rig's stream from empty.
+  rerender: () => {
+    if (cwOutputEl) cwOutputEl.innerHTML = "";
+    cwLastAppendTime = 0;
+    updateCwBar();
+  }
 });
 cwWindow.refreshCwTonePicker = function refreshCwTonePicker() {
  ensureCwToneCanvasResolution();
@@ -1,6 +1,7 @@
 import {
  initializeFtxDecoder
-} from "./chunk-O2Y7YEVQ.js";
+} from "./chunk-PAKFJPA2.js";
+import "./chunk-S57W63QN.js";
 import "./chunk-KL66PICH.js";

 // src/plugins/ft2.ts
@@ -1,6 +1,7 @@
 import {
  initializeFtxDecoder
-} from "./chunk-O2Y7YEVQ.js";
+} from "./chunk-PAKFJPA2.js";
+import "./chunk-S57W63QN.js";
 import "./chunk-KL66PICH.js";

 // src/plugins/ft4.ts
@@ -2,7 +2,8 @@ import {
  initializeFt8FamilyBar,
  initializeFtxDecoder,
  installFtxCompatibilityHelpers
-} from "./chunk-O2Y7YEVQ.js";
+} from "./chunk-PAKFJPA2.js";
+import "./chunk-S57W63QN.js";
 import "./chunk-KL66PICH.js";

 // src/plugins/ft8.ts
@@ -5,6 +5,10 @@ import {
  normalizeAprsPacket,
  renderAprsPacketRow
 } from "./chunk-OPEIVJGD.js";
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore,
  hostState
@@ -67,21 +71,26 @@ function hfAprsFilterMatch(pkt) {
  ].filter(Boolean).join(" ").toUpperCase();
  return haystack.includes(hfAprsFilterText);
 }
+function hfAprsRigPackets() {
+  return forActiveRig(hfAprsPacketHistory);
+}
 function hfAprsVisiblePackets() {
-  const packets = hfAprsCollapseDup ? collapseHfAprsDuplicates(hfAprsPacketHistory) : hfAprsPacketHistory;
+  const rigPackets = hfAprsRigPackets();
+  const packets = hfAprsCollapseDup ? collapseHfAprsDuplicates(rigPackets) : rigPackets;
  return packets.filter(hfAprsFilterMatch);
 }
 var collapseHfAprsDuplicates = collapseAprsDuplicates;
 function updateHfAprsSummary() {
+  const rigPackets = hfAprsRigPackets();
  const visible = hfAprsVisiblePackets();
  if (hfAprsTotalCountEl) {
-    hfAprsTotalCountEl.textContent = `${hfAprsPacketHistory.length} total`;
+    hfAprsTotalCountEl.textContent = `${rigPackets.length} total`;
  }
  if (hfAprsVisibleCountEl) {
    hfAprsVisibleCountEl.textContent = `${visible.length} shown`;
  }
  if (hfAprsLatestSeenEl) {
-    const latest = hfAprsPacketHistory[0];
+    const latest = rigPackets[0];
    if (!latest) {
      hfAprsLatestSeenEl.textContent = "No packets yet";
    } else {
@@ -158,10 +167,10 @@ function normalizeServerHfAprsPacket(pkt) {
 }
 function onServerHfAprsBatch(packets) {
  if (!Array.isArray(packets) || packets.length === 0) return;
-  if (hfAprsStatus) hfAprsStatus.textContent = "Receiving";
  const normalized = [];
  for (const pkt of packets) {
    const next = normalizeServerHfAprsPacket(pkt);
+    if (hfAprsStatus && isActiveRigDecode(next.rig_id)) hfAprsStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], { hour: "2-digit", minute: "2-digit", second: "2-digit" });
@@ -227,8 +236,9 @@ if (hfAprsFilterInput) {
  });
 }
 function onServerHfAprs(pkt) {
-  if (hfAprsStatus) hfAprsStatus.textContent = "Receiving";
-  addHfAprsPacket(normalizeServerHfAprsPacket(pkt));
+  const packet = normalizeServerHfAprsPacket(pkt);
+  if (hfAprsStatus && isActiveRigDecode(packet.rig_id)) hfAprsStatus.textContent = "Receiving";
+  addHfAprsPacket(packet);
 }
 renderHfAprsHistory();
 window.trxPluginRuntime.registerDecoder({
@@ -237,5 +247,6 @@ window.trxPluginRuntime.registerDecoder({
  onBatch: onServerHfAprsBatch,
  restore: onServerHfAprsBatch,
  reset: resetHfAprsHistoryView,
-  prune: pruneHfAprsHistoryView
+  prune: pruneHfAprsHistoryView,
+  rerender: renderHfAprsHistory
 });
@@ -1,3 +1,7 @@
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore
 } from "./chunk-KL66PICH.js";
@@ -111,6 +115,7 @@ function paintRow(line, rgb) {
  liveRows = Math.max(liveRows, line + 1);
 }
 function onProgress(msg) {
+  if (!isActiveRigDecode(msg.rig_id)) return;
  if (msg.state) {
    if (sstvDom.status) sstvDom.status.textContent = msg.state;
    beginPicture(msg.mode || "", msg.width || 0, msg.height || 0);
@@ -131,15 +136,20 @@ function onImage(msg) {
  sstvHistory.push(image);
  if (sstvHistory.length > SSTV_MAX_IMAGES) sstvHistory.shift();
  pruneHistory();
+  if (!isActiveRigDecode(image.rig_id)) return;
  if (sstvDom.status) {
    sstvDom.status.textContent = image.complete ? `Received ${image.mode ?? "picture"}` : `Partial ${image.mode ?? "picture"} — ${image.lines ?? 0} lines`;
  }
  scheduleUi("sstv-latest", renderLatestCard);
  if (activeView === "history") scheduleUi("sstv-history", renderHistoryTable);
 }
+function sstvRigImages() {
+  return forActiveRig(sstvHistory);
+}
 function renderLatestCard() {
  if (!sstvDom.liveLatest) return;
-  const latest = sstvHistory[sstvHistory.length - 1];
+  const rigImages = sstvRigImages();
+  const latest = rigImages[rigImages.length - 1];
  if (!latest) {
    sstvDom.liveLatest.innerHTML = "";
    return;
@@ -160,8 +170,9 @@ function renderLatestCard() {
    </div>`;
 }
 function filteredHistory() {
+  const rigImages = sstvRigImages();
  const text = filterText.trim().toLowerCase();
-  const matching = text ? sstvHistory.filter((image) => (image.mode ?? "").toLowerCase().includes(text)) : sstvHistory.slice();
+  const matching = text ? rigImages.filter((image) => (image.mode ?? "").toLowerCase().includes(text)) : rigImages;
  const newestFirst = (sstvDom.sortSelect?.value ?? "newest") === "newest";
  matching.sort((a, b) => (newestFirst ? 1 : -1) * ((b._tsMs ?? 0) - (a._tsMs ?? 0)));
  return matching;
@@ -241,7 +252,11 @@ sstvWindow.trxPluginRuntime.registerDecoder({
  onMessage: onImage,
  restore: restoreHistory,
  prune: renderHistoryTable,
-  reset: resetHistoryView
+  reset: resetHistoryView,
+  rerender: () => {
+    renderLatestCard();
+    renderHistoryTable();
+  }
 });
 sstvWindow.trxPluginRuntime.registerDecoder({
  id: "sstv_progress",
@@ -1,3 +1,7 @@
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore
 } from "./chunk-KL66PICH.js";
@@ -60,17 +64,21 @@ function vdesHexPreview(rawBytes) {
  if (!Array.isArray(rawBytes) || rawBytes.length === 0) return "--";
  return rawBytes.slice(0, 20).map((value) => value.toString(16).padStart(2, "0")).join(" ").toUpperCase();
 }
+function vdesRigMessages() {
+  return forActiveRig(vdesMessageHistory);
+}
 function updateVdesSummary() {
  pruneVdesMessageHistory();
  if (vdesChannelSummaryEl) {
    vdesChannelSummaryEl.textContent = currentVdesCenterText();
  }
+  const rigMessages = vdesRigMessages();
  if (vdesFrameCountEl) {
-    const count = vdesMessageHistory.length;
+    const count = rigMessages.length;
    vdesFrameCountEl.textContent = `${count} burst${count === 1 ? "" : "s"}`;
  }
  if (vdesLatestSeenEl) {
-    const latest = vdesMessageHistory[0];
+    const latest = rigMessages[0];
    vdesLatestSeenEl.textContent = latest ? vdesAgeText(latest._tsMs) : "No traffic yet";
  }
 }
@@ -137,7 +145,7 @@ function updateVdesBar() {
  updateVdesSummary();
  const isVdes = (document.getElementById("mode")?.value || "").toUpperCase() === "VDES";
  const cutoffMs = Date.now() - VDES_BAR_WINDOW_MS;
-  const messages = vdesMessageHistory.filter((msg) => (msg._tsMs ?? 0) >= cutoffMs).slice(0, 6);
+  const messages = vdesMessageHistory.filter((msg) => (msg._tsMs ?? 0) >= cutoffMs && isActiveRigDecode(msg.rig_id)).slice(0, 6);
  if (!isVdes || messages.length === 0) {
    vdesBarOverlay.style.display = "none";
    vdesBarOverlay.innerHTML = "";
@@ -182,7 +190,7 @@ function renderVdesHistory() {
    return;
  }
  const fragment = document.createDocumentFragment();
-  for (const message of vdesMessageHistory) {
+  for (const message of vdesRigMessages()) {
    fragment.appendChild(renderVdesRow(message));
  }
  vdesMessagesEl.replaceChildren(fragment);
@@ -209,10 +217,10 @@ function normalizeServerVdesMessage(msg) {
 }
 function onServerVdesBatch(messages) {
  if (!Array.isArray(messages) || messages.length === 0) return;
-  if (vdesStatus) vdesStatus.textContent = "Receiving";
  const normalized = [];
  for (const msg of messages) {
    const next = normalizeServerVdesMessage(msg);
+    if (vdesStatus && isActiveRigDecode(next.rig_id)) vdesStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], {
@@ -251,8 +259,8 @@ function plotVdesMessage(msg) {
  vdesWindow.vdesMapAddPoint(msg);
 }
 function onServerVdes(msg) {
-  if (vdesStatus) vdesStatus.textContent = "Receiving";
  const next = normalizeServerVdesMessage(msg);
+  if (vdesStatus && isActiveRigDecode(next.rig_id)) vdesStatus.textContent = "Receiving";
  addVdesMessage(next);
  plotVdesMessage(next);
 }
@@ -269,6 +277,10 @@ window.trxPluginRuntime.registerDecoder({
  restore: onServerVdesBatch,
  reset: resetVdesHistoryView,
  prune: pruneVdesHistoryView,
+  rerender: () => {
+    updateVdesBar();
+    renderVdesHistory();
+  },
  // Oldest first, so tracks are rebuilt in the order they happened.
  syncMap: () => {
    for (const entry of [...vdesMessageHistory].reverse()) plotVdesMessage(entry);
@@ -1,3 +1,7 @@
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore
 } from "./chunk-KL66PICH.js";
@@ -102,13 +106,17 @@ function paintLine(lineBytes) {
  wefaxLiveCtx.putImageData(imgData, 0, y);
  wefaxLiveLineCount++;
 }
+function wefaxRigImages() {
+  return forActiveRig(wefaxImageHistory);
+}
 function renderWefaxLatestCard() {
  if (!wefaxDom.liveLatest) return;
-  if (wefaxImageHistory.length === 0) {
+  const rigImages = wefaxRigImages();
+  if (rigImages.length === 0) {
    wefaxDom.liveLatest.innerHTML = '<div style="color:var(--text-muted);font-size:0.82rem;">No images decoded yet. Enable the decoder and tune to a WEFAX station.</div>';
    return;
  }
-  const img = wefaxImageHistory[0];
+  const img = rigImages[0];
  if (!img) return;
  const ts = img._ts || "--";
  const date = img._tsMs ? new Date(img._tsMs).toLocaleDateString() : "";
@@ -129,7 +137,7 @@ function renderWefaxLatestCard() {
  wefaxDom.liveLatest.innerHTML = html;
 }
 function getWefaxFilteredHistory() {
-  let items = wefaxImageHistory;
+  let items = wefaxRigImages();
  if (wefaxFilterText) {
    items = items.filter(function(i) {
      const haystack = [
@@ -173,7 +181,7 @@ function renderWefaxHistoryTable() {
  }
  wefaxDom.historyList.replaceChildren(fragment);
  if (wefaxDom.historyCount) {
-    const total = wefaxImageHistory.length;
+    const total = wefaxRigImages().length;
    const shown = items.length;
    wefaxDom.historyCount.textContent = total === 0 ? "No images yet" : shown === total ? `${String(total)} image${total === 1 ? "" : "s"}` : `${String(shown)} of ${String(total)} images`;
  }
@@ -208,6 +216,7 @@ function addWefaxImage(msg) {
  }
 }
 function onServerWefaxProgress(msg) {
+  if (!isActiveRigDecode(msg.rig_id)) return;
  if (msg.state && !msg.line_data) {
    if (wefaxDom.status) {
      wefaxDom.status.textContent = msg.state;
@@ -234,6 +243,7 @@ function onServerWefaxProgress(msg) {
 }
 function onServerWefax(msg) {
  addWefaxImage(msg);
+  if (!isActiveRigDecode(msg.rig_id)) return;
  if (wefaxDom.liveContainer) wefaxDom.liveContainer.style.display = "none";
  if (wefaxDom.status) {
    wefaxDom.status.textContent = `Complete — ${String(msg.line_count ?? 0)} lines`;
@@ -328,7 +338,11 @@ wefaxWindow.trxPluginRuntime.registerDecoder({
  onMessage: onServerWefax,
  restore: restoreWefaxHistory,
  prune: pruneWefaxHistoryView,
-  reset: resetWefaxHistoryView
+  reset: resetWefaxHistoryView,
+  rerender: () => {
+    renderWefaxLatestCard();
+    renderWefaxHistoryTable();
+  }
 });
 wefaxWindow.trxPluginRuntime.registerDecoder({
  id: "wefax_progress",
@@ -1,3 +1,7 @@
+import {
+  forActiveRig,
+  isActiveRigDecode
+} from "./chunk-S57W63QN.js";
 import {
  hostCore
 } from "./chunk-KL66PICH.js";
@@ -64,10 +68,10 @@ function renderWsprRow(msg) {
 function renderWsprHistory() {
  pruneWsprMessageHistory();
  if (!wsprMessagesEl) return;
+  const rigMessages = forActiveRig(wsprMessageHistory);
  const fragment = document.createDocumentFragment();
-  for (let i = 0; i < wsprMessageHistory.length; i += 1) {
-    const message = wsprMessageHistory[i];
-    if (message) fragment.appendChild(renderWsprRow(message));
+  for (const message of rigMessages) {
+    fragment.appendChild(renderWsprRow(message));
  }
  wsprMessagesEl.replaceChildren(fragment);
 }
@@ -90,6 +94,7 @@ function normalizeServerWsprMessage(msg) {
    station,
    rfHz,
    history: {
+      rig_id: msg.rig_id ?? null,
      receiver: wsprWindow.getDecodeRigMeta ? wsprWindow.getDecodeRigMeta() : null,
      ts_ms: msg.ts_ms,
      snr_db: msg.snr_db,
@@ -101,10 +106,10 @@ function normalizeServerWsprMessage(msg) {
 }
 function onServerWsprBatch(messages) {
  if (!Array.isArray(messages) || messages.length === 0) return;
-  if (wsprStatus) wsprStatus.textContent = "Receiving";
  const normalized = [];
  for (const msg of messages) {
    const next = normalizeServerWsprMessage(msg);
+    if (wsprStatus && isActiveRigDecode(msg.rig_id)) wsprStatus.textContent = "Receiving";
    if (next.grids.length > 0 && wsprWindow.mapAddLocator) {
      wsprWindow.mapAddLocator(next.raw, next.grids, "wspr", next.station, {
        ...msg,
@@ -251,7 +256,7 @@ document.getElementById("settings-clear-wspr-history")?.addEventListener("click"
  })();
 });
 function onServerWspr(msg) {
-  if (wsprStatus) wsprStatus.textContent = "Receiving";
+  if (wsprStatus && isActiveRigDecode(msg.rig_id)) wsprStatus.textContent = "Receiving";
  const next = normalizeServerWsprMessage(msg);
  if (next.grids.length > 0 && wsprWindow.mapAddLocator) {
    wsprWindow.mapAddLocator(next.raw, next.grids, "wspr", next.station, {
@@ -267,5 +272,6 @@ wsprWindow.trxPluginRuntime.registerDecoder({
  onBatch: onServerWsprBatch,
  restore: onServerWsprBatch,
  prune: pruneWsprHistoryView,
-  reset: resetWsprHistoryView
+  reset: resetWsprHistoryView,
+  rerender: renderWsprHistory
 });
@@ -78,6 +78,10 @@ export type RdsData = { pi?: number | null, program_service?: string | null, rad
 export type SpectrumData = { 
 /**
 * FFT magnitude bins in dBFS, FFT-shifted so DC (centre frequency) is at index N/2.
+ *
+ * On the wire these are base64-encoded `i8` whole dBFS (see
+ * `spectrum_wire`), which is what the display draws anyway; the TypeScript
+ * type describes the decoded array the browser receives over SSE.
 */
 bins: Array<number>, 
 /**
@@ -392,6 +392,7 @@ declare global {
    updateVdesBar?(value?: number): void;
    updateAprsBar?(value?: number): void;
    updateFt8Bar?(value?: number): void;
+    updateCwBar?(value?: number): void;
    updateSatLiveState?(value: unknown): void;
    applyCwAutoUi?(enabled: boolean): void;
    applyCwAutoUiFromServer?(enabled: boolean): void;
@@ -2207,6 +2208,17 @@ function resetRdsDisplay() {
  updateRdsPsOverlay(primaryRds);
 }

+// The mini views over the waterfall show only what the rig on screen heard, so
+// they have to be repainted whenever that rig — or its mode — changes, not just
+// when the next decode happens to arrive.
+function refreshDecodeBars() {
+  window.updateAisBar?.();
+  window.updateVdesBar?.();
+  window.updateAprsBar?.();
+  window.updateFt8Bar?.();
+  window.updateCwBar?.();
+}
+
 function resetDecoderStateOnRigSwitch() {
  // RDS
  primaryRds = null;
@@ -2226,6 +2238,12 @@ function resetDecoderStateOnRigSwitch() {
    const el = document.getElementById(id);
    if (el) el.textContent = "--";
  });
+
+  // The decode stream is not rig-scoped, so the histories behind the mini views
+  // and the decoder panels survive the switch: repaint both for the rig now
+  // selected instead of leaving the outgoing rig's traffic on screen.
+  refreshDecodeBars();
+  window.trxPluginRuntime.rerenderAll();
 }

 function resetWfmStereoIndicator() {
@@ -3676,10 +3694,7 @@ function render(update: AppUpdate) {
    const connText = _decodeConnectedText[d.id] || "Connected, listening for packets";
    setModeBoundDecodeStatus(el, d.active_modes, "Select " + d.active_modes[0] + " mode to decode", connText);
  }
-  if (window.updateAisBar) window.updateAisBar();
-  if (window.updateVdesBar) window.updateVdesBar();
-  if (window.updateAprsBar) window.updateAprsBar();
-  if (window.updateFt8Bar) window.updateFt8Bar();
+  refreshDecodeBars();
  // Toggle-gated decoder status: clear "Receiving" when decoder disabled or mode wrong.
  for (const d of decoderRegistry) {
    if (d.activation !== "toggle") continue;
@@ -81,6 +81,7 @@ const runtime: TrxPluginRuntime = {
    plugin.prune();
    return true;
  },
+  rerenderAll() { for (const plugin of decoders.values()) plugin.rerender?.(); },
  syncMapAll() { for (const plugin of decoders.values()) plugin.syncMap?.(); },
  clearQueued() { queued.clear(); },
  hasDecoder: (id) => decoders.has(id),
@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+import { hostState } from "./host.js";
+
+// The decode stream is not rig-scoped: every rig a client is connected to sends
+// its decodes to every browser, each frame naming the rig that heard it (the
+// client stamps `rig_id` as it leaves the audio connection).  The map wants all
+// of them — it has its own filter, and plotting only one rig would empty it —
+// but the radio page and the decoder panels describe one rig at a time: the one
+// the operator selected, whose spectrum is on screen and whose audio is
+// playing.  A frame a background rig copied on another band belongs to neither
+// picture, so both filter on this.
+export function isActiveRigDecode(rigId: string | null | undefined): boolean {
+  const activeRigId = hostState.lastActiveRigId;
+  // Before the rig list has arrived, and for a decode that reached the browser
+  // without a rig of its own, there is nothing to disagree with.
+  if (!activeRigId || !rigId) return true;
+  return rigId === activeRigId;
+}
+
+/** The decodes of `items` that the selected rig heard, in their original order. */
+export function forActiveRig<T extends { rig_id?: string | null | undefined }>(items: T[]): T[] {
+  return items.filter((item) => isActiveRigDecode(item.rig_id));
+}
@@ -6,6 +6,7 @@ import { hostCore, hostState } from "./host.js";

 export {};

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import type { PluginRuntimeWindow } from "./runtime-contract";

 interface AisMessage {
@@ -190,20 +191,27 @@ function aisLatestByVessel(messages: AisMessage[]): AisMessage[] {
  return Array.from(byMmsi.values());
 }

+/** What the selected rig heard.  The history holds every rig's traffic, for
+ *  the map; the panel is about the rig the operator is working. */
+function aisRigMessages(): AisMessage[] {
+  return forActiveRig(aisMessageHistory);
+}
+
 function updateAisSummary() {
  const plan = currentAisChannelPlan();
  if (aisChannelSummaryEl) {
    aisChannelSummaryEl.textContent = `A ${formatAisMhz(plan.aHz)} · B ${formatAisMhz(plan.bHz)}`;
  }

-  const vessels = aisLatestByVessel(aisMessageHistory);
+  const rigMessages = aisRigMessages();
+  const vessels = aisLatestByVessel(rigMessages);
  if (aisVesselCountEl) {
    const count = vessels.length;
    aisVesselCountEl.textContent = `${count} vessel${count === 1 ? "" : "s"}`;
  }

  if (aisLatestSeenEl) {
-    const latest = aisMessageHistory[0];
+    const latest = rigMessages[0];
    if (!latest) {
      aisLatestSeenEl.textContent = "No traffic yet";
    } else {
@@ -314,7 +322,9 @@ function updateAisBar() {

  const isAis = ((document.getElementById("mode") as HTMLSelectElement | null)?.value || "").toUpperCase() === "AIS";
  const cutoffMs = Date.now() - AIS_BAR_WINDOW_MS;
-  const recent = aisMessageHistory.filter((msg) => (msg._tsMs ?? 0) >= cutoffMs);
+  const recent = aisMessageHistory.filter(
+    (msg) => (msg._tsMs ?? 0) >= cutoffMs && isActiveRigDecode(msg.rig_id),
+  );
  const messages = aisLatestByVessel(recent).slice(0, 8);
  if (!isAis || messages.length === 0) {
    aisBarOverlay.style.display = "none";
@@ -368,7 +378,7 @@ function renderAisHistory() {
    return;
  }
  const fragment = document.createDocumentFragment();
-  for (const message of aisMessageHistory) {
+  for (const message of aisRigMessages()) {
    fragment.appendChild(renderAisRow(message));
  }
  aisMessagesEl.replaceChildren(fragment);
@@ -407,10 +417,11 @@ function normalizeServerAisMessage(msg: AisMessage): AisMessage {

 function onServerAisBatch(messages: AisMessage[]): void {
  if (!Array.isArray(messages) || messages.length === 0) return;
-  if (aisStatus) aisStatus.textContent = "Receiving";
  const normalized: AisMessage[] = [];
  for (const msg of messages) {
    const next = normalizeServerAisMessage(msg);
+    // "Receiving" is the panel's own status, and the panel is the rig's.
+    if (aisStatus && isActiveRigDecode(next.rig_id)) aisStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], {
@@ -452,8 +463,9 @@ if (aisFilterInput) {
 }

 function onServerAis(msg: AisMessage): void {
-  if (aisStatus) aisStatus.textContent = "Receiving";
-  addAisMessage(normalizeServerAisMessage(msg));
+  const message = normalizeServerAisMessage(msg);
+  if (aisStatus && isActiveRigDecode(message.rig_id)) aisStatus.textContent = "Receiving";
+  addAisMessage(message);
 }

 updateAisSummary();
@@ -464,6 +476,7 @@ updateAisSummary();
  restore: onServerAisBatch,
  reset: resetAisHistoryView,
  prune: pruneAisHistoryView,
+  rerender: () => { updateAisBar(); renderAisHistory(); },
  // Oldest first, so vessel tracks are rebuilt in the order they happened.
  syncMap: () => { for (const entry of [...aisMessageHistory].reverse()) plotAisMessage(entry); },
 });
@@ -4,6 +4,7 @@

 import { hostCore, hostState } from "./host.js";

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import {
  aprsAgeText,
  aprsPacketCategory,
@@ -106,21 +107,29 @@ function aprsFilterMatch(pkt: AprsPacket): boolean {
  return haystack.includes(aprsFilterText);
 }

+/** What the selected rig heard.  The history holds every rig's traffic, for
+ *  the map; the panel is about the rig the operator is working. */
+function aprsRigPackets(): AprsPacket[] {
+  return forActiveRig(aprsPacketHistory);
+}
+
 function aprsVisiblePackets(): AprsPacket[] {
-  const packets = aprsCollapseDup ? collapseAprsDuplicates(aprsPacketHistory) : aprsPacketHistory;
+  const rigPackets = aprsRigPackets();
+  const packets = aprsCollapseDup ? collapseAprsDuplicates(rigPackets) : rigPackets;
  return packets.filter(aprsFilterMatch);
 }

 function updateAprsSummary() {
+  const rigPackets = aprsRigPackets();
  const visible = aprsVisiblePackets();
  if (aprsTotalCountEl) {
-    aprsTotalCountEl.textContent = `${aprsPacketHistory.length} total`;
+    aprsTotalCountEl.textContent = `${rigPackets.length} total`;
  }
  if (aprsVisibleCountEl) {
    aprsVisibleCountEl.textContent = `${visible.length} shown`;
  }
  if (aprsLatestSeenEl) {
-    const latest = aprsPacketHistory[0];
+    const latest = rigPackets[0];
    if (!latest) {
      aprsLatestSeenEl.textContent = "No packets yet";
    } else {
@@ -179,7 +188,9 @@ function updateAprsBar() {
  if (!aprsBarOverlay) return;
  const isPkt = ((document.getElementById("mode") as HTMLSelectElement | null)?.value || "").toUpperCase() === "PKT";
  const cutoffMs = Date.now() - APRS_BAR_WINDOW_MS;
-  const okFrames = aprsPacketHistory.filter((p) => p.crcOk && (p._tsMs ?? 0) >= cutoffMs);
+  const okFrames = aprsPacketHistory.filter(
+    (p) => p.crcOk && (p._tsMs ?? 0) >= cutoffMs && isActiveRigDecode(p.rig_id),
+  );
  const frames = collapseAprsDuplicates(okFrames).slice(0, 8);
  const newestTsMs = frames.reduce((latest, pkt) => Math.max(latest, Number(pkt._tsMs) || 0), 0);
  if (!isPkt || frames.length === 0 || newestTsMs <= aprsBarDismissedAtMs) {
@@ -256,11 +267,12 @@ function normalizeServerAprsPacket(pkt: AprsPacket): AprsPacket {

 function onServerAprsBatch(packets: AprsPacket[]): void {
  if (!Array.isArray(packets) || packets.length === 0) return;
-  if (aprsStatus) aprsStatus.textContent = "Receiving";
  const normalized: AprsPacket[] = [];
  let hasCrcOk = false;
  for (const pkt of packets) {
    const next = normalizeServerAprsPacket(pkt);
+    // "Receiving" is the panel's own status, and the panel is the rig's.
+    if (aprsStatus && isActiveRigDecode(next.rig_id)) aprsStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], { hour: "2-digit", minute: "2-digit", second: "2-digit" });
@@ -324,8 +336,9 @@ if (aprsFilterInput) {

 // --- Server-side APRS decode handler ---
 function onServerAprs(pkt: AprsPacket): void {
-  if (aprsStatus) aprsStatus.textContent = "Receiving";
-  addAprsPacket(normalizeServerAprsPacket(pkt));
+  const packet = normalizeServerAprsPacket(pkt);
+  if (aprsStatus && isActiveRigDecode(packet.rig_id)) aprsStatus.textContent = "Receiving";
+  addAprsPacket(packet);
 }

 renderAprsHistory();
@@ -336,6 +349,7 @@ renderAprsHistory();
  restore: onServerAprsBatch,
  reset: resetAprsHistoryView,
  prune: pruneAprsHistoryView,
+  rerender: () => { updateAprsBar(); renderAprsHistory(); },
  // Oldest first, so station tracks are rebuilt in the order they happened.
  syncMap: () => { for (const entry of [...aprsPacketHistory].reverse()) plotAprsPacket(entry); },
 });
@@ -4,6 +4,7 @@

 import { hostCore } from "./host.js";

+import { isActiveRigDecode } from "./active-rig.js";
 import type { PluginRuntimeWindow } from "./runtime-contract.js";

 export {};
@@ -20,8 +21,11 @@ interface CwRenderer {
  drawPoints(points: number[], size: number, color: Rgba): void;
 }
 interface CwSpectrum { bins: number[]; sample_rate: number; center_hz: number }
-interface CwEvent { text?: string; wpm?: number; tone_hz?: number; signal_on?: boolean }
-interface CwLine { tsMs: number; ts: string; text: string; wpm: number | null; tone_hz: number | null; lastMs: number }
+interface CwEvent { rig_id?: string | null; text?: string; wpm?: number; tone_hz?: number; signal_on?: boolean }
+interface CwLine {
+  rigId: string | null; tsMs: number; ts: string; text: string;
+  wpm: number | null; tone_hz: number | null; lastMs: number;
+}
 interface CwToneRange {
  tunedHz: number; bandwidthHz: number; toneMinHz: number; toneMaxHz: number;
  toneSpanHz: number; lowerSideband: boolean; mode: string;
@@ -66,7 +70,10 @@ const CW_BAR_LINE_GAP_MS = 5000;
 let cwLastAppendTime = 0;
 let cwTonePickerRaf: number | null = null;
 let cwBarHistory: CwLine[] = [];
-let cwBarCurrentLine: CwLine | null = null;
+// One line in progress per rig, keyed by rig id ("" for a decode that names no
+// rig).  Two rigs copying at the same time each fill their own line instead of
+// braiding their characters into one.
+const cwBarCurrentLines = new Map<string, CwLine>();
 let cwBarDismissedAtMs = 0;
 // Tracks a user-initiated auto toggle that is in-flight (POST not yet
 // acknowledged).  While set, server-state updates must not override the
@@ -101,12 +108,13 @@ cwWindow.applyCwAutoUiFromServer = function(enabled: boolean) {
  applyCwAutoUi(enabled);
 };

-function cwBarFlushCurrentLine(): void {
-  if (cwBarCurrentLine && cwBarCurrentLine.text.trim()) {
-    cwBarHistory.unshift(cwBarCurrentLine);
+function cwBarFlushCurrentLine(key: string): void {
+  const line = cwBarCurrentLines.get(key);
+  cwBarCurrentLines.delete(key);
+  if (line?.text.trim()) {
+    cwBarHistory.unshift(line);
    if (cwBarHistory.length > 50) cwBarHistory.length = 50;
  }
-  cwBarCurrentLine = null;
 }

 function updateCwBar(): void {
@@ -114,9 +122,12 @@ function updateCwBar(): void {
  const mode = ((document.getElementById("mode") as HTMLSelectElement | null)?.value || "").toUpperCase();
  const isCw = mode === "CW" || mode === "CWR";
  const cutoffMs = Date.now() - CW_BAR_WINDOW_MS;
-  const recent = cwBarHistory.filter((l) => l.tsMs >= cutoffMs);
-  // Prepend the in-progress line so characters appear immediately
-  const liveLines = cwBarCurrentLine && cwBarCurrentLine.text ? [cwBarCurrentLine, ...recent] : recent;
+  const recent = cwBarHistory.filter((l) => l.tsMs >= cutoffMs && isActiveRigDecode(l.rigId));
+  // Prepend the in-progress lines so characters appear immediately
+  const inProgress = [...cwBarCurrentLines.values()]
+    .filter((l) => l.text && isActiveRigDecode(l.rigId))
+    .sort((a, b) => b.tsMs - a.tsMs);
+  const liveLines = [...inProgress, ...recent];
  const newestTsMs = liveLines.reduce((latest, line) => Math.max(latest, line.tsMs || 0), 0);
  if (!isCw || liveLines.length === 0 || newestTsMs <= cwBarDismissedAtMs) {
    cwBarOverlay.style.display = "none";
@@ -402,7 +413,7 @@ function resetCwHistoryView(): void {
  if (cwOutputEl) cwOutputEl.innerHTML = "";
  cwLastAppendTime = 0;
  cwBarHistory = [];
-  cwBarCurrentLine = null;
+  cwBarCurrentLines.clear();
  updateCwBar();
  drawCwTonePicker();
 }
@@ -421,8 +432,13 @@ document.getElementById("settings-clear-cw-history")?.addEventListener("click",

 // --- Server-side CW decode handler ---
 function onServerCw(evt: CwEvent): void {
-  if (cwStatusEl) cwStatusEl.textContent = "Receiving";
-  if (evt.text && cwOutputEl) {
+  // The panel is a single stream of copied text: characters from a background
+  // rig do not belong in it at all, and interleaving them would make both
+  // rigs unreadable.  The bar histories below keep every rig, each on its own
+  // line, and pick out the selected rig when they paint.
+  const forSelectedRig = isActiveRigDecode(evt.rig_id ?? null);
+  if (cwStatusEl && forSelectedRig) cwStatusEl.textContent = "Receiving";
+  if (evt.text && cwOutputEl && forSelectedRig) {
    // Append decoded text to output
    const now = Date.now();
    if (!cwOutputEl.lastElementChild || now - cwLastAppendTime > 10000 || evt.text === "\n") {
@@ -445,25 +461,29 @@ function onServerCw(evt: CwEvent): void {
  // Bar history accumulation (regardless of pause state)
  if (evt.text) {
    const now = Date.now();
+    const rigId = evt.rig_id ?? null;
+    const key = rigId ?? "";
    if (evt.text === "\n") {
-      cwBarFlushCurrentLine();
+      cwBarFlushCurrentLine(key);
    } else {
-      if (!cwBarCurrentLine || now - cwBarCurrentLine.lastMs > CW_BAR_LINE_GAP_MS) {
-        cwBarFlushCurrentLine();
+      let line = cwBarCurrentLines.get(key);
+      if (!line || now - line.lastMs > CW_BAR_LINE_GAP_MS) {
+        cwBarFlushCurrentLine(key);
        const ts = new Date(now).toLocaleTimeString([], { hour: "2-digit", minute: "2-digit", second: "2-digit" });
-        cwBarCurrentLine = { tsMs: now, ts, text: "", wpm: null, tone_hz: null, lastMs: now };
+        line = { rigId, tsMs: now, ts, text: "", wpm: null, tone_hz: null, lastMs: now };
+        cwBarCurrentLines.set(key, line);
      }
-      cwBarCurrentLine.text += evt.text;
-      cwBarCurrentLine.lastMs = now;
-      if (Number.isFinite(Number(evt.wpm))) cwBarCurrentLine.wpm = clampCwWpm(evt.wpm);
-      if (Number.isFinite(Number(evt.tone_hz))) cwBarCurrentLine.tone_hz = Math.round(Number(evt.tone_hz));
+      line.text += evt.text;
+      line.lastMs = now;
+      if (Number.isFinite(Number(evt.wpm))) line.wpm = clampCwWpm(evt.wpm);
+      if (Number.isFinite(Number(evt.tone_hz))) line.tone_hz = Math.round(Number(evt.tone_hz));
    }
    updateCwBar();
  }
-  if (cwSignalIndicator) {
+  if (cwSignalIndicator && forSelectedRig) {
    cwSignalIndicator.className = evt.signal_on ? "cw-signal-on" : "cw-signal-off";
  }
-  if (!cwAutoInput || cwAutoInput.checked) {
+  if (forSelectedRig && (!cwAutoInput || cwAutoInput.checked)) {
    if (cwWpmInput && Number.isFinite(Number(evt.wpm))) {
      cwWpmInput.value = String(clampCwWpm(evt.wpm));
    }
@@ -491,6 +511,13 @@ cwWindow.trxPluginRuntime.registerDecoder({
  onMessage: onServerCw,
  restore: restoreCwHistory,
  reset: resetCwHistoryView,
+  // The copied text of a rig that is no longer on screen cannot be unpicked
+  // from the pane, so the switch starts the new rig's stream from empty.
+  rerender: () => {
+    if (cwOutputEl) cwOutputEl.innerHTML = "";
+    cwLastAppendTime = 0;
+    updateCwBar();
+  },
 });

 cwWindow.refreshCwTonePicker = function refreshCwTonePicker() {
@@ -4,6 +4,7 @@

 import { hostCore } from "./host.js";

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import type { PluginRuntimeWindow } from "./runtime-contract.js";

 export type FtxDecoderId = "ft2" | "ft4" | "ft8";
@@ -15,6 +16,7 @@ export interface FtxMessage {
  snr_db?: number | undefined;
  dt_s?: number | undefined;
  freq_hz?: number | undefined;
+  rig_id?: string | null | undefined;
  receiver?: unknown;
  [key: string]: unknown;
 }
@@ -227,9 +229,12 @@ export function initializeFtxDecoder(config: FtxConfig): void {
  const render = (): void => {
    prune();
    if (!messagesElement) return;
+    // The history holds every rig's decodes, for the map; the panel is about
+    // the rig the operator is working.
+    const rigMessages = forActiveRig(history);
    const fragment = document.createDocumentFragment();
    let count = 0;
-    for (const message of history) {
+    for (const message of rigMessages) {
      if (count >= 200) break;
      if (filterText && !(message.message ?? "").toUpperCase().includes(filterText)) continue;
      fragment.appendChild(renderRow(message));
@@ -251,6 +256,9 @@ export function initializeFtxDecoder(config: FtxConfig): void {
      });
    }
    return {
+      // The rig that heard it, kept so the mini view can tell a decode of the
+      // rig on screen from one a background rig made on another band.
+      rig_id: message.rig_id ?? null,
      receiver: bridge.getDecodeRigMeta?.() ?? null,
      ts_ms: message.ts_ms,
      snr_db: message.snr_db,
@@ -262,7 +270,10 @@ export function initializeFtxDecoder(config: FtxConfig): void {
  };
  const receiveBatch = (messages: FtxMessage[]): void => {
    if (messages.length === 0) return;
-    if (status) status.textContent = "Receiving";
+    // "Receiving" is the panel's own status, and the panel is the rig's.
+    if (status && messages.some((message) => isActiveRigDecode(message.rig_id))) {
+      status.textContent = "Receiving";
+    }
    history = messages.map(normalize).reverse().concat(history);
    prune();
    bridge.setFt8FamilyBarDecoder?.(id);
@@ -277,7 +288,8 @@ export function initializeFtxDecoder(config: FtxConfig): void {
  };
  const barFrames = (): BarFrames => {
    const recent = history
-      .filter((message) => (finiteNumber(message._tsMs ?? message.ts_ms) ?? 0) >= Date.now() - 900_000)
+      .filter((message) => (finiteNumber(message._tsMs ?? message.ts_ms) ?? 0) >= Date.now() - 900_000
+        && isActiveRigDecode(message.rig_id))
      .slice(0, 8);
    let html = "";
    for (const message of recent) {
@@ -299,6 +311,7 @@ export function initializeFtxDecoder(config: FtxConfig): void {
    restore: receiveBatch,
    prune: () => { prune(); render(); },
    reset,
+    rerender: () => { bridge.updateFt8Bar?.(); render(); },
  });
  bridge.registerFt8FamilyBarRenderer?.(id, barFrames);

@@ -4,6 +4,7 @@

 import { hostCore, hostState } from "./host.js";

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import {
  aprsAgeText,
  aprsPacketCategory,
@@ -90,23 +91,31 @@ function hfAprsFilterMatch(pkt: AprsPacket): boolean {
  return haystack.includes(hfAprsFilterText);
 }

+/** What the selected rig heard.  The history holds every rig's traffic, for
+ *  the map; the panel is about the rig the operator is working. */
+function hfAprsRigPackets(): AprsPacket[] {
+  return forActiveRig(hfAprsPacketHistory);
+}
+
 function hfAprsVisiblePackets(): AprsPacket[] {
-  const packets = hfAprsCollapseDup ? collapseHfAprsDuplicates(hfAprsPacketHistory) : hfAprsPacketHistory;
+  const rigPackets = hfAprsRigPackets();
+  const packets = hfAprsCollapseDup ? collapseHfAprsDuplicates(rigPackets) : rigPackets;
  return packets.filter(hfAprsFilterMatch);
 }

 const collapseHfAprsDuplicates = collapseAprsDuplicates;

 function updateHfAprsSummary() {
+  const rigPackets = hfAprsRigPackets();
  const visible = hfAprsVisiblePackets();
  if (hfAprsTotalCountEl) {
-    hfAprsTotalCountEl.textContent = `${hfAprsPacketHistory.length} total`;
+    hfAprsTotalCountEl.textContent = `${rigPackets.length} total`;
  }
  if (hfAprsVisibleCountEl) {
    hfAprsVisibleCountEl.textContent = `${visible.length} shown`;
  }
  if (hfAprsLatestSeenEl) {
-    const latest = hfAprsPacketHistory[0];
+    const latest = rigPackets[0];
    if (!latest) {
      hfAprsLatestSeenEl.textContent = "No packets yet";
    } else {
@@ -192,10 +201,11 @@ function normalizeServerHfAprsPacket(pkt: AprsPacket): AprsPacket {

 function onServerHfAprsBatch(packets: AprsPacket[]): void {
  if (!Array.isArray(packets) || packets.length === 0) return;
-  if (hfAprsStatus) hfAprsStatus.textContent = "Receiving";
  const normalized: AprsPacket[] = [];
  for (const pkt of packets) {
    const next = normalizeServerHfAprsPacket(pkt);
+    // "Receiving" is the panel's own status, and the panel is the rig's.
+    if (hfAprsStatus && isActiveRigDecode(next.rig_id)) hfAprsStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], { hour: "2-digit", minute: "2-digit", second: "2-digit" });
@@ -266,8 +276,9 @@ if (hfAprsFilterInput) {

 // --- Server-side HF APRS decode handler ---
 function onServerHfAprs(pkt: AprsPacket): void {
-  if (hfAprsStatus) hfAprsStatus.textContent = "Receiving";
-  addHfAprsPacket(normalizeServerHfAprsPacket(pkt));
+  const packet = normalizeServerHfAprsPacket(pkt);
+  if (hfAprsStatus && isActiveRigDecode(packet.rig_id)) hfAprsStatus.textContent = "Receiving";
+  addHfAprsPacket(packet);
 }

 renderHfAprsHistory();
@@ -278,4 +289,5 @@ renderHfAprsHistory();
  restore: onServerHfAprsBatch,
  reset: resetHfAprsHistoryView,
  prune: pruneHfAprsHistoryView,
+  rerender: renderHfAprsHistory,
 });
@@ -9,6 +9,10 @@ export interface DecoderPlugin<TMessage = unknown> {
  restore?(messages: TMessage[]): void;
  reset?(): void;
  prune?(): void;
+  /** Repaint the plugin's panel from what it already holds. Called when the
+   *  selected rig changes: the panels show one rig's traffic, and the decodes
+   *  behind them arrived long before the switch. */
+  rerender?(): void;
  /** Replay everything the plugin is holding onto the map. Called when the map
   *  module attaches, which can happen long after the decodes arrived. */
  syncMap?(): void;
@@ -22,6 +26,7 @@ export interface TrxPluginRuntime {
  reset(id: string): boolean;
  resetAll(): void;
  prune(id: string): boolean;
+  rerenderAll(): void;
  syncMapAll(): void;
  clearQueued(): void;
  hasDecoder(id: string): boolean;
@@ -14,11 +14,13 @@

 import { hostCore } from "./host.js";

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import type { PluginRuntimeWindow } from "./runtime-contract.js";

 export {};

 interface SstvImage {
+  rig_id?: string | null;
  ts_ms?: number;
  vis?: number;
  mode?: string;
@@ -32,6 +34,7 @@ interface SstvImage {
 }

 interface SstvProgress {
+  rig_id?: string | null;
  state?: string;
  mode?: string;
  width?: number;
@@ -185,6 +188,9 @@ function paintRow(line: number, rgb: Uint8Array): void {
 // ── Server messages ─────────────────────────────────────────────────

 function onProgress(msg: SstvProgress): void {
+  // The live canvas draws one picture at a time: a background rig's rows would
+  // paint straight over the one being watched.
+  if (!isActiveRigDecode(msg.rig_id)) return;
  if (msg.state) {
    if (sstvDom.status) sstvDom.status.textContent = msg.state;
    // A state update carries the geometry; a row update carries only the row.
@@ -208,6 +214,9 @@ function onImage(msg: SstvImage): void {
  if (sstvHistory.length > SSTV_MAX_IMAGES) sstvHistory.shift();
  pruneHistory();

+  // Kept in the history either way, so switching to that rig finds it there.
+  if (!isActiveRigDecode(image.rig_id)) return;
+
  if (sstvDom.status) {
    sstvDom.status.textContent = image.complete
      ? `Received ${image.mode ?? "picture"}`
@@ -219,9 +228,15 @@ function onImage(msg: SstvImage): void {

 // ── Rendering ───────────────────────────────────────────────────────

+/** The pictures the selected rig decoded, oldest first, as the history is kept. */
+function sstvRigImages(): SstvImage[] {
+  return forActiveRig(sstvHistory);
+}
+
 function renderLatestCard(): void {
  if (!sstvDom.liveLatest) return;
-  const latest = sstvHistory[sstvHistory.length - 1];
+  const rigImages = sstvRigImages();
+  const latest = rigImages[rigImages.length - 1];
  if (!latest) {
    sstvDom.liveLatest.innerHTML = "";
    return;
@@ -245,10 +260,12 @@ function renderLatestCard(): void {
 }

 function filteredHistory(): SstvImage[] {
+  // Every rig's pictures are kept; the panel shows the selected rig's.
+  const rigImages = sstvRigImages();
  const text = filterText.trim().toLowerCase();
  const matching = text
-    ? sstvHistory.filter((image) => (image.mode ?? "").toLowerCase().includes(text))
-    : sstvHistory.slice();
+    ? rigImages.filter((image) => (image.mode ?? "").toLowerCase().includes(text))
+    : rigImages;
  const newestFirst = (sstvDom.sortSelect?.value ?? "newest") === "newest";
  matching.sort((a, b) => (newestFirst ? 1 : -1) * ((b._tsMs ?? 0) - (a._tsMs ?? 0)));
  return matching;
@@ -348,6 +365,7 @@ sstvWindow.trxPluginRuntime.registerDecoder({
  restore: restoreHistory,
  prune: renderHistoryTable,
  reset: resetHistoryView,
+  rerender: () => { renderLatestCard(); renderHistoryTable(); },
 });
 sstvWindow.trxPluginRuntime.registerDecoder({
  id: "sstv_progress",
@@ -6,6 +6,7 @@ import { hostCore } from "./host.js";

 export {};

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import type { PluginRuntimeWindow } from "./runtime-contract";

 interface VdesMessage {
@@ -116,17 +117,24 @@ function vdesHexPreview(rawBytes: number[] | undefined): string {
    .toUpperCase();
 }

+/** What the selected rig heard.  The history holds every rig's traffic, for
+ *  the map; the panel is about the rig the operator is working. */
+function vdesRigMessages(): VdesMessage[] {
+  return forActiveRig(vdesMessageHistory);
+}
+
 function updateVdesSummary() {
  pruneVdesMessageHistory();
  if (vdesChannelSummaryEl) {
    vdesChannelSummaryEl.textContent = currentVdesCenterText();
  }
+  const rigMessages = vdesRigMessages();
  if (vdesFrameCountEl) {
-    const count = vdesMessageHistory.length;
+    const count = rigMessages.length;
    vdesFrameCountEl.textContent = `${count} burst${count === 1 ? "" : "s"}`;
  }
  if (vdesLatestSeenEl) {
-    const latest = vdesMessageHistory[0];
+    const latest = rigMessages[0];
    vdesLatestSeenEl.textContent = latest ? vdesAgeText(latest._tsMs) : "No traffic yet";
  }
 }
@@ -228,7 +236,9 @@ function updateVdesBar() {
  updateVdesSummary();
  const isVdes = ((document.getElementById("mode") as HTMLSelectElement | null)?.value || "").toUpperCase() === "VDES";
  const cutoffMs = Date.now() - VDES_BAR_WINDOW_MS;
-  const messages = vdesMessageHistory.filter((msg) => (msg._tsMs ?? 0) >= cutoffMs).slice(0, 6);
+  const messages = vdesMessageHistory
+    .filter((msg) => (msg._tsMs ?? 0) >= cutoffMs && isActiveRigDecode(msg.rig_id))
+    .slice(0, 6);
  if (!isVdes || messages.length === 0) {
    vdesBarOverlay.style.display = "none";
    vdesBarOverlay.innerHTML = "";
@@ -278,7 +288,7 @@ function renderVdesHistory() {
    return;
  }
  const fragment = document.createDocumentFragment();
-  for (const message of vdesMessageHistory) {
+  for (const message of vdesRigMessages()) {
    fragment.appendChild(renderVdesRow(message));
  }
  vdesMessagesEl.replaceChildren(fragment);
@@ -309,10 +319,11 @@ function normalizeServerVdesMessage(msg: VdesMessage): VdesMessage {

 function onServerVdesBatch(messages: VdesMessage[]): void {
  if (!Array.isArray(messages) || messages.length === 0) return;
-  if (vdesStatus) vdesStatus.textContent = "Receiving";
  const normalized: VdesMessage[] = [];
  for (const msg of messages) {
    const next = normalizeServerVdesMessage(msg);
+    // "Receiving" is the panel's own status, and the panel is the rig's.
+    if (vdesStatus && isActiveRigDecode(next.rig_id)) vdesStatus.textContent = "Receiving";
    const tsMs = Number.isFinite(next.ts_ms) ? Number(next.ts_ms) : Date.now();
    next._tsMs = tsMs;
    next._ts = new Date(tsMs).toLocaleTimeString([], {
@@ -354,8 +365,8 @@ function plotVdesMessage(msg: VdesMessage): void {
 }

 function onServerVdes(msg: VdesMessage): void {
-  if (vdesStatus) vdesStatus.textContent = "Receiving";
  const next = normalizeServerVdesMessage(msg);
+  if (vdesStatus && isActiveRigDecode(next.rig_id)) vdesStatus.textContent = "Receiving";
  addVdesMessage(next);
  plotVdesMessage(next);
 }
@@ -374,6 +385,7 @@ updateVdesSummary();
  restore: onServerVdesBatch,
  reset: resetVdesHistoryView,
  prune: pruneVdesHistoryView,
+  rerender: () => { updateVdesBar(); renderVdesHistory(); },
  // Oldest first, so tracks are rebuilt in the order they happened.
  syncMap: () => { for (const entry of [...vdesMessageHistory].reverse()) plotVdesMessage(entry); },
 });
@@ -4,11 +4,13 @@

 import { hostCore } from "./host.js";

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import type { PluginRuntimeWindow } from "./runtime-contract.js";

 export {};

 interface WefaxImage {
+  rig_id?: string | null;
  ts_ms?: number;
  ioc?: number;
  lpm?: number;
@@ -20,6 +22,7 @@ interface WefaxImage {
 }

 interface WefaxProgress {
+  rig_id?: string | null;
  state?: string;
  line_data?: string;
  line_count?: number;
@@ -156,15 +159,21 @@ function paintLine(lineBytes: Uint8Array): void {
 }

 // ── Live view: latest image card ────────────────────────────────────
+/** The pictures the selected rig decoded, newest first. */
+function wefaxRigImages(): WefaxImage[] {
+  return forActiveRig(wefaxImageHistory);
+}
+
 function renderWefaxLatestCard() {
  if (!wefaxDom.liveLatest) return;
-  if (wefaxImageHistory.length === 0) {
+  const rigImages = wefaxRigImages();
+  if (rigImages.length === 0) {
    wefaxDom.liveLatest.innerHTML =
      '<div style="color:var(--text-muted);font-size:0.82rem;">No images decoded yet. Enable the decoder and tune to a WEFAX station.</div>';
    return;
  }

-  const img = wefaxImageHistory[0];
+  const img = rigImages[0];
  if (!img) return;
  const ts = img._ts || '--';
  const date = img._tsMs ? new Date(img._tsMs).toLocaleDateString() : '';
@@ -193,7 +202,8 @@ function renderWefaxLatestCard() {

 // ── History view: table ─────────────────────────────────────────────
 function getWefaxFilteredHistory() {
-  let items = wefaxImageHistory;
+  // Every rig's pictures are kept; the panel shows the selected rig's.
+  let items = wefaxRigImages();

  if (wefaxFilterText) {
    items = items.filter(function (i) {
@@ -253,7 +263,7 @@ function renderWefaxHistoryTable() {
  wefaxDom.historyList.replaceChildren(fragment);

  if (wefaxDom.historyCount) {
-    const total = wefaxImageHistory.length;
+    const total = wefaxRigImages().length;
    const shown = items.length;
    wefaxDom.historyCount.textContent =
      total === 0
@@ -298,6 +308,9 @@ function addWefaxImage(msg: WefaxImage): void {

 // ── SSE event handlers (public API) ─────────────────────────────────
 function onServerWefaxProgress(msg: WefaxProgress): void {
+  // The live canvas draws one picture at a time: a background rig's lines
+  // would paint straight over the one being watched.
+  if (!isActiveRigDecode(msg.rig_id)) return;
  // State-only update (no image data): show decoder state in status.
  if (msg.state && !msg.line_data) {
    if (wefaxDom.status) {
@@ -331,6 +344,8 @@ function onServerWefaxProgress(msg: WefaxProgress): void {

 function onServerWefax(msg: WefaxImage): void {
  addWefaxImage(msg);
+  // Kept in the history either way, so switching to that rig finds it there.
+  if (!isActiveRigDecode(msg.rig_id)) return;

  if (wefaxDom.liveContainer) wefaxDom.liveContainer.style.display = 'none';
  if (wefaxDom.status) {
@@ -438,6 +453,7 @@ wefaxWindow.trxPluginRuntime.registerDecoder({
  restore: restoreWefaxHistory,
  prune: pruneWefaxHistoryView,
  reset: resetWefaxHistoryView,
+  rerender: () => { renderWefaxLatestCard(); renderWefaxHistoryTable(); },
 });
 wefaxWindow.trxPluginRuntime.registerDecoder({
  id: "wefax_progress",
@@ -4,6 +4,7 @@

 import { hostCore } from "./host.js";

+import { forActiveRig, isActiveRigDecode } from "./active-rig.js";
 import type { PluginRuntimeWindow } from "./runtime-contract.js";

 export {};
@@ -15,6 +16,7 @@ interface WsprMessage {
  snr_db?: number | undefined;
  dt_s?: number | undefined;
  freq_hz?: number | undefined;
+  rig_id?: string | null | undefined;
  receiver?: unknown;
  [key: string]: unknown;
 }
@@ -102,10 +104,12 @@ function renderWsprRow(msg: WsprMessage): HTMLDivElement {
 function renderWsprHistory(): void {
  pruneWsprMessageHistory();
  if (!wsprMessagesEl) return;
+  // The history holds every rig's decodes, for the map; the panel is about the
+  // rig the operator is working.
+  const rigMessages = forActiveRig(wsprMessageHistory);
  const fragment = document.createDocumentFragment();
-  for (let i = 0; i < wsprMessageHistory.length; i += 1) {
-    const message = wsprMessageHistory[i];
-    if (message) fragment.appendChild(renderWsprRow(message));
+  for (const message of rigMessages) {
+    fragment.appendChild(renderWsprRow(message));
  }
  wsprMessagesEl.replaceChildren(fragment);
 }
@@ -130,6 +134,7 @@ function normalizeServerWsprMessage(msg: WsprMessage): { raw: string; grids: str
    station,
    rfHz,
    history: {
+      rig_id: msg.rig_id ?? null,
      receiver: wsprWindow.getDecodeRigMeta ? wsprWindow.getDecodeRigMeta() : null,
      ts_ms: msg.ts_ms,
      snr_db: msg.snr_db,
@@ -142,10 +147,11 @@ function normalizeServerWsprMessage(msg: WsprMessage): { raw: string; grids: str

 function onServerWsprBatch(messages: WsprMessage[]): void {
  if (!Array.isArray(messages) || messages.length === 0) return;
-  if (wsprStatus) wsprStatus.textContent = "Receiving";
  const normalized: WsprMessage[] = [];
  for (const msg of messages) {
    const next = normalizeServerWsprMessage(msg);
+    // "Receiving" is the panel's own status, and the panel is the rig's.
+    if (wsprStatus && isActiveRigDecode(msg.rig_id)) wsprStatus.textContent = "Receiving";
    if (next.grids.length > 0 && wsprWindow.mapAddLocator) {
      wsprWindow.mapAddLocator(next.raw, next.grids, "wspr", next.station, {
        ...msg,
@@ -312,7 +318,7 @@ document.getElementById("settings-clear-wspr-history")?.addEventListener("click"
 });

 function onServerWspr(msg: WsprMessage): void {
-  if (wsprStatus) wsprStatus.textContent = "Receiving";
+  if (wsprStatus && isActiveRigDecode(msg.rig_id)) wsprStatus.textContent = "Receiving";
  const next = normalizeServerWsprMessage(msg);
  if (next.grids.length > 0 && wsprWindow.mapAddLocator) {
    wsprWindow.mapAddLocator(next.raw, next.grids, "wspr", next.station, {
@@ -330,4 +336,5 @@ wsprWindow.trxPluginRuntime.registerDecoder({
  restore: onServerWsprBatch,
  prune: pruneWsprHistoryView,
  reset: resetWsprHistoryView,
+  rerender: renderWsprHistory,
 });
@@ -0,0 +1,348 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+// The radio page and the digital modes page both describe one rig: the one the
+// operator selected.  Every rig a client is connected to feeds the same decode
+// stream, so both the mini views over the waterfall and the panels behind them
+// filter on the rig that heard each decode.  The map is the exception and keeps
+// all of them — it has its own rig filter — which is why the histories these
+// views read from are never pruned by rig.
+
+import assert from "node:assert/strict";
+import test from "node:test";
+import vm from "node:vm";
+import { bundleEntry } from "./bundle-entry.mjs";
+import { createHost } from "./host-fixture.mjs";
+
+class ElementFixture {
+  constructor(value = "") {
+    this.children = [];
+    this.innerHTML = "";
+    this.textContent = "";
+    this.value = value;
+    this.style = {};
+    this.dataset = {};
+    this.classList = { add() {}, remove() {}, toggle() {} };
+  }
+  appendChild(child) { this.children.push(child); return child; }
+  removeChild(child) { this.children.splice(this.children.indexOf(child), 1); }
+  replaceChildren(...nodes) { this.children = nodes.flatMap((node) => node.children ?? [node]); }
+  addEventListener() {}
+  setAttribute() {}
+  querySelector() { return null; }
+  querySelectorAll() { return []; }
+  get firstChild() { return this.children[0] ?? null; }
+  get lastElementChild() { return this.children.at(-1) ?? null; }
+  get scrollHeight() { return this.children.length; }
+}
+
+/** A document whose named elements exist and whose unknown ones do not. */
+function createDocument(elements) {
+  return {
+    documentElement: {},
+    getElementById: (id) => elements.get(id) ?? null,
+    querySelector: () => null,
+    querySelectorAll: () => [],
+    createElement: () => new ElementFixture(),
+    createDocumentFragment: () => new ElementFixture(),
+  };
+}
+
+async function runPlugin(entry, { window, document: doc, extras = {} }) {
+  const context = vm.createContext({
+    window,
+    document: doc,
+    navigator: {},
+    requestAnimationFrame(callback) { callback(); return 1; },
+    getComputedStyle: () => ({ getPropertyValue: () => "" }),
+    Date, Number, String, Math, Array, Map, Set, Reflect, console,
+    ...extras,
+  });
+  const runtime = await bundleEntry(new URL("../src/plugin-runtime.ts", import.meta.url));
+  const source = await bundleEntry(new URL(`../src/plugins/${entry}.ts`, import.meta.url));
+  new vm.Script(runtime).runInContext(context);
+  new vm.Script(source).runInContext(context);
+  return context;
+}
+
+test("the APRS mini view and panel both keep to the active rig", async () => {
+  const overlay = new ElementFixture();
+  const packets = new ElementFixture();
+  const totals = new ElementFixture();
+  const elements = new Map([
+    ["aprs-bar-overlay", overlay],
+    ["aprs-packets", packets],
+    ["aprs-total-count", totals],
+    ["mode", new ElementFixture("PKT")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    trxUi: { confirm: async () => true },
+    aprsMapAddStation: () => {},
+  };
+  await runPlugin("aprs", { window, document: createDocument(elements) });
+
+  const frame = { dest_call: "APRS", packet_type: "position", crc_ok: true, info: "beacon" };
+  window.trxPluginRuntime.dispatch("aprs", { ...frame, src_call: "SP1AAA", rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("aprs", { ...frame, src_call: "SP2BBB", rig_id: "rig-b" });
+
+  assert.match(overlay.innerHTML, /SP1AAA/, "the active rig's frame is missing from the mini view");
+  assert.doesNotMatch(overlay.innerHTML, /SP2BBB/, "a background rig's frame reached the mini view");
+  assert.equal(packets.children.length, 1, "the APRS panel listed a background rig's frame");
+  assert.equal(totals.textContent, "1 total", `the APRS panel counted "${totals.textContent}"`);
+});
+
+test("the APRS mini view shows every frame until a rig is known", async () => {
+  const overlay = new ElementFixture();
+  const elements = new Map([
+    ["aprs-bar-overlay", overlay],
+    ["mode", new ElementFixture("PKT")],
+  ]);
+  const window = {
+    ...createHost(),
+    trxUi: { confirm: async () => true },
+    aprsMapAddStation: () => {},
+  };
+  await runPlugin("aprs", { window, document: createDocument(elements) });
+
+  const frame = { dest_call: "APRS", packet_type: "position", crc_ok: true, info: "beacon" };
+  window.trxPluginRuntime.dispatch("aprs", { ...frame, src_call: "SP1AAA", rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("aprs", { ...frame, src_call: "SP2BBB" });
+
+  assert.match(overlay.innerHTML, /SP1AAA/);
+  assert.match(overlay.innerHTML, /SP2BBB/);
+});
+
+test("the AIS mini view keeps to the active rig", async () => {
+  const overlay = new ElementFixture();
+  const elements = new Map([
+    ["ais-bar-overlay", overlay],
+    ["mode", new ElementFixture("AIS")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    trxUi: { confirm: async () => true },
+    aisMapAddVessel: () => {},
+  };
+  await runPlugin("ais", { window, document: createDocument(elements) });
+
+  const now = Date.now();
+  window.trxPluginRuntime.dispatch("ais", { mmsi: 261000001, vessel_name: "NEARBY", channel: "A", ts_ms: now, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("ais", { mmsi: 261000002, vessel_name: "ELSEWHERE", channel: "A", ts_ms: now, rig_id: "rig-b" });
+
+  assert.match(overlay.innerHTML, /NEARBY/);
+  assert.doesNotMatch(overlay.innerHTML, /ELSEWHERE/, "a background rig's vessel reached the mini view");
+});
+
+test("the VDES mini view keeps to the active rig", async () => {
+  const overlay = new ElementFixture();
+  const elements = new Map([
+    ["vdes-bar-overlay", overlay],
+    ["mode", new ElementFixture("VDES")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    trxUi: { confirm: async () => true },
+    vdesMapAddPoint: () => {},
+  };
+  await runPlugin("vdes", { window, document: createDocument(elements) });
+
+  const now = Date.now();
+  window.trxPluginRuntime.dispatch("vdes", { callsign: "SP1AAA", bit_len: 120, ts_ms: now, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("vdes", { callsign: "SP2BBB", bit_len: 120, ts_ms: now, rig_id: "rig-b" });
+
+  assert.match(overlay.innerHTML, /SP1AAA/);
+  assert.doesNotMatch(overlay.innerHTML, /SP2BBB/, "a background rig's burst reached the mini view");
+});
+
+test("the CW mini view keeps to the active rig and does not braid two rigs into a line", async () => {
+  const overlay = new ElementFixture();
+  const elements = new Map([
+    ["cw-bar-overlay", overlay],
+    ["cw-output", new ElementFixture()],
+    ["mode", new ElementFixture("CW")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    trxUi: { confirm: async () => true },
+    addEventListener() {},
+  };
+  await runPlugin("cw", { window, document: createDocument(elements) });
+
+  window.trxPluginRuntime.dispatch("cw", { text: "CQ ", wpm: 18, tone_hz: 700, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("cw", { text: "DX ", wpm: 22, tone_hz: 600, rig_id: "rig-b" });
+  window.trxPluginRuntime.dispatch("cw", { text: "SP1AAA", wpm: 18, tone_hz: 700, rig_id: "rig-a" });
+
+  assert.match(overlay.innerHTML, /CQ SP1AAA/, "the active rig's line was broken up or lost");
+  assert.doesNotMatch(overlay.innerHTML, /DX/, "a background rig's characters reached the mini view");
+});
+
+test("the FT8 mini view keeps to the active rig", async () => {
+  const overlay = new ElementFixture();
+  const elements = new Map([
+    ["ft8-bar-overlay", overlay],
+    ["mode", new ElementFixture("DIG")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    ft8BaseHz: 7_074_000,
+    trxUi: { confirm: async () => true },
+    mapAddLocator: () => {},
+    setInterval() { return 1; },
+  };
+  await runPlugin("ft8", { window, document: createDocument(elements) });
+
+  const now = Date.now();
+  window.trxPluginRuntime.dispatch("ft8", { message: "CQ SP1AAA JO91", freq_hz: 500, ts_ms: now, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("ft8", { message: "CQ SP2BBB JO94", freq_hz: 800, ts_ms: now, rig_id: "rig-b" });
+
+  assert.match(overlay.innerHTML, /SP1AAA/);
+  assert.doesNotMatch(overlay.innerHTML, /SP2BBB/, "a background rig's decode reached the mini view");
+});
+
+// ── The digital modes panels ───────────────────────────────────────────────
+// The same rule one page over: a panel lists the selected rig's decodes only.
+
+test("the AIS panel lists the active rig's vessels only", async () => {
+  const messages = new ElementFixture();
+  const count = new ElementFixture();
+  const elements = new Map([
+    ["ais-messages", messages],
+    ["ais-vessel-count", count],
+    ["mode", new ElementFixture("AIS")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    trxUi: { confirm: async () => true },
+    aisMapAddVessel: () => {},
+  };
+  await runPlugin("ais", { window, document: createDocument(elements) });
+
+  const now = Date.now();
+  window.trxPluginRuntime.dispatch("ais", { mmsi: 261000001, vessel_name: "NEARBY", channel: "A", ts_ms: now, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("ais", { mmsi: 261000002, vessel_name: "ELSEWHERE", channel: "A", ts_ms: now, rig_id: "rig-b" });
+
+  assert.equal(messages.children.length, 1, "the AIS panel listed a background rig's vessel");
+  assert.equal(count.textContent, "1 vessel", `the panel counted "${count.textContent}"`);
+});
+
+test("the VDES panel lists the active rig's bursts only", async () => {
+  const messages = new ElementFixture();
+  const count = new ElementFixture();
+  const elements = new Map([
+    ["vdes-messages", messages],
+    ["vdes-frame-count", count],
+    ["mode", new ElementFixture("VDES")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    trxUi: { confirm: async () => true },
+    vdesMapAddPoint: () => {},
+  };
+  await runPlugin("vdes", { window, document: createDocument(elements) });
+
+  const now = Date.now();
+  window.trxPluginRuntime.dispatch("vdes", { callsign: "SP1AAA", bit_len: 120, ts_ms: now, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("vdes", { callsign: "SP2BBB", bit_len: 120, ts_ms: now, rig_id: "rig-b" });
+
+  assert.equal(messages.children.length, 1, "the VDES panel listed a background rig's burst");
+  assert.equal(count.textContent, "1 burst", `the panel counted "${count.textContent}"`);
+});
+
+test("the FT8 panel lists the active rig's decodes only", async () => {
+  const messages = new ElementFixture();
+  const elements = new Map([
+    ["ft8-messages", messages],
+    ["mode", new ElementFixture("DIG")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    ft8BaseHz: 7_074_000,
+    trxUi: { confirm: async () => true },
+    mapAddLocator: () => {},
+    setInterval() { return 1; },
+  };
+  await runPlugin("ft8", { window, document: createDocument(elements) });
+
+  const now = Date.now();
+  window.trxPluginRuntime.dispatch("ft8", { message: "CQ SP1AAA JO91", freq_hz: 500, ts_ms: now, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("ft8", { message: "CQ SP2BBB JO94", freq_hz: 800, ts_ms: now, rig_id: "rig-b" });
+
+  assert.equal(messages.children.length, 1, "the FT8 panel listed a background rig's decode");
+});
+
+test("the WSPR panel lists the active rig's spots only", async () => {
+  const messages = new ElementFixture();
+  const elements = new Map([
+    ["wspr-messages", messages],
+    ["mode", new ElementFixture("DIG")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    ft8BaseHz: 14_095_600,
+    trxUi: { confirm: async () => true },
+    mapAddLocator: () => {},
+  };
+  await runPlugin("wspr", {
+    window,
+    document: createDocument(elements),
+    extras: { setInterval: () => 1 },
+  });
+
+  const now = Date.now();
+  window.trxPluginRuntime.dispatch("wspr", { message: "SP1AAA JO91 30", freq_hz: 1_500, ts_ms: now, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("wspr", { message: "SP2BBB JO94 27", freq_hz: 1_520, ts_ms: now, rig_id: "rig-b" });
+
+  assert.equal(messages.children.length, 1, "the WSPR panel listed a background rig's spot");
+});
+
+test("the CW pane copies the active rig only", async () => {
+  const output = new ElementFixture();
+  const elements = new Map([
+    ["cw-output", output],
+    ["cw-bar-overlay", new ElementFixture()],
+    ["mode", new ElementFixture("CW")],
+  ]);
+  const window = {
+    ...createHost({ state: { lastActiveRigId: "rig-a" } }),
+    trxUi: { confirm: async () => true },
+    addEventListener() {},
+  };
+  await runPlugin("cw", { window, document: createDocument(elements) });
+
+  window.trxPluginRuntime.dispatch("cw", { text: "CQ ", wpm: 18, tone_hz: 700, rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("cw", { text: "XX ", wpm: 22, tone_hz: 600, rig_id: "rig-b" });
+  window.trxPluginRuntime.dispatch("cw", { text: "SP1AAA", wpm: 18, tone_hz: 700, rig_id: "rig-a" });
+
+  const copied = output.children.map((line) => line.textContent).join("");
+  assert.equal(copied, "CQ SP1AAA", `the pane copied "${copied}"`);
+});
+
+test("switching rigs repaints the panels through the runtime", async () => {
+  const packets = new ElementFixture();
+  const elements = new Map([
+    ["aprs-packets", packets],
+    ["aprs-bar-overlay", new ElementFixture()],
+    ["mode", new ElementFixture("PKT")],
+  ]);
+  // A mutable host: the rig picker writes lastActiveRigId, and the panels read
+  // it as they paint.
+  const host = createHost({ state: { lastActiveRigId: "rig-a" } });
+  let activeRigId = "rig-a";
+  Object.defineProperty(host.trx.state, "lastActiveRigId", { get: () => activeRigId });
+  const window = { ...host, trxUi: { confirm: async () => true }, aprsMapAddStation: () => {} };
+  await runPlugin("aprs", { window, document: createDocument(elements) });
+
+  const frame = { dest_call: "APRS", packet_type: "position", crc_ok: true, info: "beacon" };
+  window.trxPluginRuntime.dispatch("aprs", { ...frame, src_call: "SP1AAA", rig_id: "rig-a" });
+  window.trxPluginRuntime.dispatch("aprs", { ...frame, src_call: "SP2BBB", rig_id: "rig-b" });
+  assert.equal(packets.children.length, 1);
+
+  activeRigId = "rig-b";
+  window.trxPluginRuntime.rerenderAll();
+  assert.equal(packets.children.length, 1, "the panel did not follow the switch");
+  const shown = packets.children.map((row) => row.innerHTML).join("");
+  assert.match(shown, /SP2BBB/, "the panel still shows the rig that was switched away from");
+  assert.doesNotMatch(shown, /SP1AAA/);
+});
@@ -22,9 +22,18 @@ const BEACON = {
  packet_type: "position", crc_ok: true, lat: 54.35, lon: 18.65,
  symbol_table: "/", symbol_code: ">", rig_id: "rig-a",
 };
+// A second rig listening in the background, on its own band. Both pages
+// describe the rig on screen, so its traffic belongs in neither the panel nor
+// the mini view — only on the map, which shows the whole station.
+const OTHER_RIG_VESSEL = {
+  ...VESSEL, mmsi: 244660001, vessel_name: "ELDERBERRY", callsign: "PBTY",
+  lat: 51.92, lon: 4.48, rig_id: "rig-b",
+};

 // AIS is what the mini view for vessels is gated on; the rig has to be on it.
-const fixture = await startWebFixture({ spectrum: true, decodes: [VESSEL, BEACON], mode: "AIS" });
+const fixture = await startWebFixture({
+  spectrum: true, decodes: [VESSEL, BEACON, OTHER_RIG_VESSEL], mode: "AIS",
+});
 const { browser, page, runtimeErrors } = await startBrowser(chromium);

 try {
@@ -41,11 +50,14 @@ try {
    aprs: document.getElementById("aprs-packets")?.children.length ?? 0,
    aisStatus: document.getElementById("ais-status")?.textContent ?? "",
    aprsStatus: document.getElementById("aprs-status")?.textContent ?? "",
+    otherRig: document.getElementById("ais-messages")?.textContent.includes("ELDERBERRY") ?? false,
+    aisRows: document.getElementById("ais-messages")?.children.length ?? 0,
    mapLoaded: !!window.trx.modules.map,
  }));
  assert.equal(panels.mapLoaded, false, "the map module was loaded, so this proves nothing");
  assert.ok(panels.ais > 0, `the AIS panel is empty (status: ${panels.aisStatus})`);
  assert.ok(panels.aprs > 0, `the APRS panel is empty (status: ${panels.aprsStatus})`);
+  assert.equal(panels.otherRig, false, "the AIS panel listed a background rig's vessel");

  // The mini view rides over the waterfall on the radio page.
  await page.locator('.tab[data-tab="main"]').click();
@@ -56,11 +68,13 @@ try {
      shown: getComputedStyle(bar).display !== "none",
      pins: bar.querySelectorAll(".aprs-bar-pin").length,
      names: bar.textContent.includes("NEDERLAND"),
+      otherRig: bar.textContent.includes("ELDERBERRY"),
    };
  });
  assert.equal(miniView.shown, true, "the AIS mini view did not appear");
  assert.ok(miniView.pins > 0, "the mini view has no pin to follow");
  assert.equal(miniView.names, true, "the mini view does not name the vessel");
+  assert.equal(miniView.otherRig, false, "the mini view shows a background rig's vessel");

  // Following the pin: the map opens, on the vessel. This is the path that was
  // broken for every decoder — the module that owned the navigation had not
@@ -89,8 +103,11 @@ try {
      : Object.keys(collection ?? {}).length);
    return { ais: size(map?.aisMarkers), stations: size(map?.stationMarkers) };
  });
-  assert.ok(markers.ais > 0, "the vessel never reached the map");
  assert.ok(markers.stations > 0, "the APRS station never reached the map");
+  // The map is the whole station's view — the one place a background rig's
+  // traffic belongs — so both vessels are on it even though the panel and the
+  // mini view show only the selected rig's.
+  assert.equal(markers.ais, 2, `${markers.ais} of 2 vessels reached the map`);

  assert.deepEqual(runtimeErrors, []);
 } finally {
@@ -27,6 +27,21 @@ const dial = () => page.evaluate(() => ({
  path: window.location.pathname,
 }));

+// Typed, not filled. The app holds back its own refreshes of the frequency
+// field from the first keystroke until Enter, so that a state update arriving
+// mid-edit does not rewrite what is being typed. `fill()` sets the value
+// without a keystroke, leaving the field unguarded: on a slow machine a state
+// update could land between the fill and the Enter and put the old frequency
+// back, and the Enter would then re-apply the frequency the radio was already
+// on. Selecting first arms the guard before a single character changes.
+async function tuneByHand(text) {
+  const field = page.locator("#freq");
+  await field.click();
+  await field.press("ControlOrMeta+a");
+  await field.pressSequentially(text);
+  await field.press("Enter");
+}
+
 try {
  await page.setViewportSize({ width: 1500, height: 950 });

@@ -49,8 +64,7 @@ try {

  // Tuning by hand rewrites the link. This is the part that makes the address
  // bar shareable at any moment rather than only at load.
-  await page.locator("#freq").fill("7.040M");
-  await page.locator("#freq").press("Enter");
+  await tuneByHand("7.040M");
  await page.waitForTimeout(1500);
  const tuned = await dial();
  assert.equal(tuned.freqHz, TUNED_HZ, `tuning landed on ${tuned.freqHz} Hz`);
@@ -59,8 +73,7 @@ try {

  // Tuning is not navigation: a swept dial must not bury the back button.
  const historyLength = await page.evaluate(() => window.history.length);
-  await page.locator("#freq").fill("7.100M");
-  await page.locator("#freq").press("Enter");
+  await tuneByHand("7.100M");
  await page.waitForTimeout(1200);
  assert.equal(await page.evaluate(() => window.history.length), historyLength,
    "tuning pushed a history entry instead of replacing one");
@@ -0,0 +1,24 @@
+# SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+[package]
+name = "trx-config"
+version.workspace = true
+edition = "2021"
+license = "GPL-2.0-or-later"
+
+[dependencies]
+serde = { workspace = true, features = ["derive"] }
+toml = { workspace = true }
+tracing = { workspace = true }
+dirs = "6"
+thiserror = "2"
+trx-core = { path = "../trx-core" }
+trx-decode-log = { path = "../decoders/trx-decode-log" }
+trx-reporting = { path = "../trx-reporting" }
+serde_ignored = "0.1"
+toml_edit = "0.22"
+
+[dev-dependencies]
+tempfile = "3"
@@ -0,0 +1,29 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Regenerate `trx-rs.toml.example` from the config structs.
+//!
+//! Run from anywhere in the workspace:
+//!
+//! ```text
+//! cargo run -p trx-config --example generate_example
+//! ```
+//!
+//! A test in `trx_config::example` fails when the checked-in file no longer
+//! matches, which is the reminder to run this.
+
+use std::path::PathBuf;
+
+fn main() -> std::io::Result<()> {
+    let target: PathBuf = std::env::args()
+        .nth(1)
+        .map(PathBuf::from)
+        .unwrap_or_else(|| {
+            PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("../../trx-rs.toml.example")
+        });
+
+    std::fs::write(&target, trx_config::example::combined_example())?;
+    println!("Wrote {}", target.display());
+    Ok(())
+}
@@ -0,0 +1,295 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Generating the example configuration from the config structs.
+//!
+//! `trx-rs.toml.example` used to be maintained by hand and had fallen years
+//! behind the code — no `[[rigs]]`, no `[[remotes]]`, no `[timeouts]`, no
+//! bandplan settings.  It is now produced from the structs themselves, so a new
+//! field appears in the example the moment it exists, and a test fails if the
+//! checked-in copy drifts.
+//!
+//! Section comments come from the table below.  A section without an entry is
+//! still emitted — only its explanatory text is missing — so forgetting to add
+//! one can never drop a setting from the example.
+
+use toml_edit::{DocumentMut, Item};
+
+use crate::{ClientConfig, ServerConfig};
+
+const HEADER: &str = "\
+# trx-rs example configuration
+#
+# Generated from the config structs; regenerate with:
+#     cargo run -p trx-config --example generate_example
+#
+# Both sections are optional: trx-server reads [trx-server], trx-client reads
+# [trx-client], and either may live in its own file with the section header
+# omitted.  Any string may use ${ENV_VAR}, and credentials may be moved out of
+# this file with the matching *_file keys.
+#
+# Check a config without starting anything:
+#     trx-server --check-config --config trx-rs.toml
+#     trx-client --check-config --config trx-rs.toml
+";
+
+/// Explanatory comments for config sections, keyed by dotted path.
+const SECTION_COMMENTS: &[(&str, &str)] = &[
+    ("trx-server", "Server: drives the radio hardware."),
+    (
+        "trx-server.general",
+        "Station identity.  Coordinates feed PSKReporter and the map.",
+    ),
+    (
+        "trx-server.rig",
+        "Single-rig layout.  For several radios, delete this and use [[rigs]].",
+    ),
+    (
+        "trx-server.rig.access",
+        "How to reach the radio: serial, tcp, or sdr.",
+    ),
+    ("trx-server.behavior", "CAT polling and retry behaviour."),
+    (
+        "trx-server.listen",
+        "JSON control listener that trx-client connects to.",
+    ),
+    (
+        "trx-server.listen.auth",
+        "Tokens clients must present.  Empty means no authentication.\n\
+         Use tokens_file = \"/etc/trx-rs/tokens\" to keep them out of this file.",
+    ),
+    ("trx-server.audio", "Opus audio stream for trx-client."),
+    (
+        "trx-server.decoders",
+        "Which decoders run.  Trimming this list saves real CPU on small boxes.\n\
+         Valid names: aprs, aprs_hf, ais, cw, ft2, ft4, ft8, lrpt, sstv, vdes, wefax, wspr.\n\
+         output_dir sets where sstv/wefax/lrpt write images (default: user cache dir).",
+    ),
+    (
+        "trx-server.pskreporter",
+        "Report FT8/FT4/WSPR spots to pskreporter.info.",
+    ),
+    (
+        "trx-server.aprsfi",
+        "Forward received APRS frames to APRS-IS.",
+    ),
+    (
+        "trx-server.decode_logs",
+        "Write decodes to JSON Lines files.",
+    ),
+    (
+        "trx-server.sdr",
+        "SoapySDR pipeline; used when [rig.access] type = \"sdr\".",
+    ),
+    (
+        "trx-server.sdr.gain",
+        "\"auto\" for hardware AGC, or \"manual\".",
+    ),
+    (
+        "trx-server.sdr.squelch",
+        "Software squelch on demodulated audio.",
+    ),
+    (
+        "trx-server.sdr.noise_blanker",
+        "Impulse-noise suppression on the IQ stream.",
+    ),
+    (
+        "trx-server.timeouts",
+        "Timeout and buffer tuning.  The defaults suit most setups.",
+    ),
+    ("trx-client", "Client: exposes the radio to users."),
+    ("trx-client.general", "Labels shown in the web UI."),
+    (
+        "trx-client.remote",
+        "Legacy single-remote form; prefer [[remotes]] below.",
+    ),
+    (
+        "trx-client.frontends.http",
+        "Web UI.  default_rig_name and the per-rig maps are keyed by the\n\
+         [[remotes]] name, not the server-side rig id.",
+    ),
+    (
+        "trx-client.frontends.http.auth",
+        "Passphrase login for the web UI.  rx_passphrase_file and\n\
+         control_passphrase_file keep the secrets out of this file.",
+    ),
+    (
+        "trx-client.frontends.rigctl",
+        "Hamlib-compatible TCP interface, one listener per rig.",
+    ),
+    (
+        "trx-client.frontends.http_json",
+        "JSON-over-TCP control interface.",
+    ),
+    (
+        "trx-client.frontends.audio",
+        "Where to fetch the audio stream from.",
+    ),
+    (
+        "trx-client.frontends.audio.bridge",
+        "Play RX audio on a local sound device and capture TX from one.",
+    ),
+];
+
+/// Render the combined `trx-rs.toml.example` contents.
+pub fn combined_example() -> String {
+    let mut doc = DocumentMut::new();
+    doc.decor_mut().set_prefix(HEADER);
+
+    doc.insert("trx-server", section_item(&ServerConfig::example_config()));
+    doc.insert("trx-client", section_item(&ClientConfig::example_config()));
+
+    // Each section was serialized on its own, so both carry table positions
+    // starting at zero and would otherwise render interleaved.
+    renumber_tables(&mut doc);
+
+    for (path, comment) in SECTION_COMMENTS {
+        annotate(&mut doc, path, comment);
+    }
+
+    doc.to_string()
+}
+
+/// Renumber every table so the document renders in tree order.
+fn renumber_tables(doc: &mut DocumentMut) {
+    fn walk(item: &mut Item, next: &mut usize) {
+        match item {
+            Item::Table(table) => {
+                table.set_position(*next);
+                *next += 1;
+                for (_, child) in table.iter_mut() {
+                    walk(child, next);
+                }
+            }
+            Item::ArrayOfTables(array) => {
+                for table in array.iter_mut() {
+                    table.set_position(*next);
+                    *next += 1;
+                    for (_, child) in table.iter_mut() {
+                        walk(child, next);
+                    }
+                }
+            }
+            _ => {}
+        }
+    }
+
+    let mut next = 0;
+    for (_, item) in doc.as_table_mut().iter_mut() {
+        walk(item, &mut next);
+    }
+}
+
+/// Serialize one config into a toml_edit table.
+fn section_item<T: serde::Serialize>(config: &T) -> Item {
+    let rendered = toml::to_string_pretty(config).unwrap_or_default();
+    let doc: DocumentMut = rendered.parse().expect("serialized config must re-parse");
+    Item::Table(doc.as_table().clone())
+}
+
+/// Attach a comment above the table at `path`, if it exists.
+fn annotate(doc: &mut DocumentMut, path: &str, comment: &str) {
+    let mut item: Option<&mut Item> = None;
+    for segment in path.split('.') {
+        let next = match item {
+            None => doc.get_mut(segment),
+            Some(current) => current.as_table_mut().and_then(|t| t.get_mut(segment)),
+        };
+        match next {
+            Some(found) => item = Some(found),
+            None => return,
+        }
+    }
+
+    let Some(table) = item.and_then(|i| i.as_table_mut()) else {
+        return;
+    };
+    let body: String = comment
+        .lines()
+        .map(|line| format!("# {}\n", line.trim_start()))
+        .collect();
+    table.decor_mut().set_prefix(format!("\n{body}"));
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// The checked-in example must match what the structs produce, so a new
+    /// config field cannot land without showing up in the example.
+    #[test]
+    fn test_checked_in_example_is_up_to_date() {
+        let path = std::path::Path::new(env!("CARGO_MANIFEST_DIR"))
+            .join("../../trx-rs.toml.example")
+            .canonicalize()
+            .expect("example file must exist");
+        let on_disk = std::fs::read_to_string(&path).expect("example file must be readable");
+        assert_eq!(
+            on_disk,
+            combined_example(),
+            "trx-rs.toml.example is out of date; regenerate with \
+             `cargo run -p trx-config --example generate_example`"
+        );
+    }
+
+    /// Nothing in the example may be derived from the machine that generated
+    /// it: [decode_logs].dir defaults to the running user's cache directory,
+    /// which made the generated file differ between a developer's laptop and
+    /// CI, and the up-to-date test fail for everyone but its author.
+    #[test]
+    fn test_example_has_no_machine_specific_paths() {
+        let example = combined_example();
+        for dir in [dirs::home_dir(), dirs::cache_dir(), dirs::config_dir()]
+            .into_iter()
+            .flatten()
+        {
+            let dir = dir.to_string_lossy().into_owned();
+            assert!(
+                !example.contains(&dir),
+                "the example contains this machine's {dir}; pin the value in example_config()"
+            );
+        }
+    }
+
+    #[test]
+    fn test_example_loads_and_validates() {
+        let mut file = tempfile::NamedTempFile::new().unwrap();
+        std::io::Write::write_all(&mut file, combined_example().as_bytes()).unwrap();
+
+        let server = ServerConfig::load_from_file(file.path()).expect("server section loads");
+        assert!(
+            server.unknown_keys.is_empty(),
+            "the generated example must not contain unknown keys: {:?}",
+            server.unknown_keys
+        );
+        server.config.validate().expect("server section validates");
+
+        let client = ClientConfig::load_from_file(file.path()).expect("client section loads");
+        assert!(
+            client.unknown_keys.is_empty(),
+            "the generated example must not contain unknown keys: {:?}",
+            client.unknown_keys
+        );
+        client.config.validate().expect("client section validates");
+    }
+
+    /// Every section that gained a comment must still exist under that path.
+    #[test]
+    fn test_section_comments_match_real_sections() {
+        let doc: DocumentMut = combined_example().parse().unwrap();
+        for (path, _) in SECTION_COMMENTS {
+            let mut item = None;
+            for segment in path.split('.') {
+                item = match item {
+                    None => doc.get(segment),
+                    Some(current) => current.as_table().and_then(|t| t.get(segment)),
+                };
+                assert!(
+                    item.is_some(),
+                    "commented section [{path}] no longer exists"
+                );
+            }
+        }
+    }
+}
@@ -0,0 +1,252 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Loading a config section out of a TOML file.
+//!
+//! Two file shapes are accepted:
+//!
+//! - **Sectioned** — a combined `trx-rs.toml` with `[trx-server]` and/or
+//!   `[trx-client]` tables.  This is what `--print-config` and
+//!   `trx-configurator` emit.
+//! - **Bare** — a standalone file whose root *is* the section, i.e. `[general]`
+//!   and `[rig]` at the top level.  Hand-written per-binary configs use this.
+//!
+//! A file that carries some other component's section but not ours is treated
+//! as "section absent" rather than as a bare file, so loading a client-only
+//! config with the server reports the missing section instead of silently
+//! falling back to defaults.
+
+use serde::de::DeserializeOwned;
+use serde::Serialize;
+use std::path::{Path, PathBuf};
+use thiserror::Error;
+
+use std::collections::BTreeSet;
+
+use crate::unknown::{describe, flatten_paths, UnknownKey};
+
+/// Every section key that may appear at the root of a combined config file.
+pub const SECTION_KEYS: &[&str] = &["trx-server", "trx-client"];
+
+/// A loaded config plus what the loader noticed on the way in.
+#[derive(Debug, Clone)]
+pub struct ConfigLoad<T> {
+    /// The deserialized configuration.
+    pub config: T,
+    /// File the config came from; `None` when nothing was found and defaults
+    /// were used.
+    pub path: Option<PathBuf>,
+    /// Keys present in the file that no config field claimed.
+    pub unknown_keys: Vec<UnknownKey>,
+    /// Every key path the file actually set.  Defaults are indistinguishable
+    /// from explicit values once deserialized, so deprecation checks need this.
+    pub present_keys: BTreeSet<String>,
+}
+
+impl<T: ConfigFile> ConfigLoad<T> {
+    /// Log a warning for every deprecated key the file sets.
+    pub fn report_deprecations(&self) {
+        for message in T::deprecations(&self.present_keys) {
+            tracing::warn!("{}", message);
+        }
+    }
+}
+
+impl<T> ConfigLoad<T> {
+    /// Log every unknown key as a warning.  With `strict`, also return an error
+    /// so the caller can refuse to start.
+    pub fn report_unknown_keys(&self, strict: bool) -> Result<(), String> {
+        for key in &self.unknown_keys {
+            tracing::warn!("{}", key);
+        }
+        if strict && !self.unknown_keys.is_empty() {
+            return Err(format!(
+                "{} unknown config key(s); refusing to start because --strict-config is set",
+                self.unknown_keys.len()
+            ));
+        }
+        Ok(())
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum ConfigError {
+    #[error("Failed to read config file {0}: {1}")]
+    ReadError(PathBuf, String),
+
+    #[error("Failed to parse config file {0}: {1}")]
+    ParseError(PathBuf, String),
+}
+
+/// Returns the default search paths for `trx-rs.toml`
+/// (current directory → XDG config → /etc).
+fn config_search_paths() -> Vec<PathBuf> {
+    let mut paths = vec![PathBuf::from("trx-rs.toml")];
+    if let Some(config_dir) = dirs::config_dir() {
+        paths.push(config_dir.join("trx-rs").join("trx-rs.toml"));
+    }
+    paths.push(PathBuf::from("/etc/trx-rs/trx-rs.toml"));
+    paths
+}
+
+/// Pick the table holding `key`'s settings out of a parsed document.
+///
+/// Returns the named section when present, the whole document when it carries
+/// no section headers at all (a bare standalone file), or `None` when the file
+/// is sectioned but has no section for `key`.
+fn select_section(table: &toml::Table, key: &str) -> Option<toml::Value> {
+    if let Some(section) = table.get(key) {
+        return Some(section.clone());
+    }
+    let is_sectioned = SECTION_KEYS.iter().any(|k| table.contains_key(*k));
+    if is_sectioned {
+        return None;
+    }
+    Some(toml::Value::Table(table.clone()))
+}
+
+/// Extract and deserialize a named section from a TOML file.
+///
+/// Returns `Ok(Some((cfg, unknown_keys)))` when the section is present and
+/// parses cleanly, `Ok(None)` when the section is absent, or `Err` on I/O /
+/// parse failure.
+type LoadedSection<T> = (T, Vec<UnknownKey>, BTreeSet<String>);
+
+fn load_section_from_file<T: ConfigFile>(
+    path: &Path,
+    key: &str,
+) -> Result<Option<LoadedSection<T>>, ConfigError> {
+    let content = std::fs::read_to_string(path)
+        .map_err(|e| ConfigError::ReadError(path.to_path_buf(), e.to_string()))?;
+
+    let table: toml::Table = toml::from_str(&content)
+        .map_err(|e| ConfigError::ParseError(path.to_path_buf(), e.to_string()))?;
+
+    let Some(mut section) = select_section(&table, key) else {
+        return Ok(None);
+    };
+
+    // ${VAR} references are expanded before deserializing, so any string in the
+    // file can come from the environment.
+    crate::secrets::expand_env_vars(&mut section)
+        .map_err(|e| ConfigError::ParseError(path.to_path_buf(), e))?;
+
+    let present_keys = flatten_paths(&section);
+
+    // Deserialize straight from the TOML value so serde applies every default,
+    // recording any key no field claimed.
+    let mut ignored: Vec<String> = Vec::new();
+    let cfg: T = serde_ignored::deserialize(section, |path| ignored.push(path.to_string()))
+        .map_err(|e| ConfigError::ParseError(path.to_path_buf(), e.to_string()))?;
+
+    Ok(Some((
+        cfg,
+        describe(&ignored, &T::reference_value()),
+        present_keys,
+    )))
+}
+
+/// Trait for loading configuration from a `trx-rs.toml` section.
+pub trait ConfigFile: Sized + Default + DeserializeOwned + Serialize {
+    /// Section key in `trx-rs.toml` (e.g. `"trx-server"` or `"trx-client"`).
+    fn section_key() -> &'static str;
+
+    /// Warnings for deprecated keys the file sets, given every key path present
+    /// in it.  Defaults to none.
+    fn deprecations(_present_keys: &BTreeSet<String>) -> Vec<String> {
+        Vec::new()
+    }
+
+    /// A TOML rendering of a populated config, used to suggest corrections for
+    /// unknown keys.  Implementations should fill in list-valued sections such
+    /// as `[[rigs]]` so keys nested inside them can be suggested too.
+    fn reference_value() -> toml::Value {
+        toml::Value::try_from(Self::default())
+            .unwrap_or_else(|_| toml::Value::Table(toml::Table::new()))
+    }
+
+    /// Load the section from a specific file path.
+    ///
+    /// Accepts both a sectioned file (`[<section_key>]` at the root) and a bare
+    /// file whose root is the section itself.  Returns an error if the file
+    /// cannot be read, is not valid TOML, or is sectioned for some other
+    /// component only.
+    fn load_from_file(path: &Path) -> Result<ConfigLoad<Self>, ConfigError> {
+        let (config, unknown_keys, present_keys) =
+            load_section_from_file::<Self>(path, Self::section_key())?.ok_or_else(|| {
+                ConfigError::ParseError(
+                    path.to_path_buf(),
+                    format!("missing [{}] section", Self::section_key()),
+                )
+            })?;
+        Ok(ConfigLoad {
+            config,
+            path: Some(path.to_path_buf()),
+            unknown_keys,
+            present_keys,
+        })
+    }
+
+    /// Search default paths (`trx-rs.toml` in CWD → XDG → /etc) and load
+    /// the first file that contains the expected section.
+    ///
+    /// Falls back to `Self::default()` with no path when nothing is found.
+    fn load_from_default_paths() -> Result<ConfigLoad<Self>, ConfigError> {
+        for path in config_search_paths() {
+            if path.exists() {
+                if let Some((config, unknown_keys, present_keys)) =
+                    load_section_from_file::<Self>(&path, Self::section_key())?
+                {
+                    return Ok(ConfigLoad {
+                        config,
+                        path: Some(path),
+                        unknown_keys,
+                        present_keys,
+                    });
+                }
+            }
+        }
+        Ok(ConfigLoad {
+            config: Self::default(),
+            path: None,
+            unknown_keys: Vec::new(),
+            present_keys: BTreeSet::new(),
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn table(s: &str) -> toml::Table {
+        toml::from_str(s).unwrap()
+    }
+
+    #[test]
+    fn test_select_section_prefers_named_section() {
+        let t = table("[trx-server]\n[trx-server.general]\ncallsign = \"W1AW\"\n");
+        let section = select_section(&t, "trx-server").unwrap();
+        assert!(section.get("general").is_some());
+    }
+
+    #[test]
+    fn test_select_section_falls_back_to_root_for_bare_file() {
+        let t = table("[general]\ncallsign = \"W1AW\"\n");
+        let section = select_section(&t, "trx-server").unwrap();
+        assert!(section.get("general").is_some());
+    }
+
+    #[test]
+    fn test_select_section_absent_when_other_section_present() {
+        let t = table("[trx-client]\n[trx-client.general]\ncallsign = \"W1AW\"\n");
+        assert!(select_section(&t, "trx-server").is_none());
+    }
+
+    #[test]
+    fn test_select_section_empty_file_is_bare() {
+        let t = table("");
+        assert!(select_section(&t, "trx-server").is_some());
+    }
+}
@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Configuration types shared by `trx-server`, `trx-client` and
+//! `trx-configurator`.
+//!
+//! Keeping the structs, the loader and the validators in one crate means the
+//! setup wizard checks a config with exactly the same code the binaries load
+//! it with, so the two can never drift apart.
+
+pub mod client;
+pub mod example;
+pub mod file;
+pub mod secrets;
+pub mod server;
+pub mod shared;
+pub mod unknown;
+pub mod url;
+
+pub use client::ClientConfig;
+pub use file::{ConfigError, ConfigFile, ConfigLoad};
+pub use server::ServerConfig;
+pub use shared::{validate_log_level, validate_tokens};
+pub use unknown::UnknownKey;
+pub use url::{parse_audio_url, parse_remote_url, RemoteEndpoint};
@@ -0,0 +1,297 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Keeping credentials out of the config file.
+//!
+//! Tokens and passphrases used to have exactly one representation: written in
+//! plain text in `trx-rs.toml`, which is awkward when the config is deployed by
+//! a config-management tool, committed to a private repo, or shared between
+//! machines.  Two alternatives are offered:
+//!
+//! - `${VAR}` anywhere in a config string, expanded from the environment.
+//! - A `*_file` sibling of any secret key, read from disk at startup.
+//!
+//! Plus a nudge: a config that holds secrets and is readable by group or others
+//! gets a warning.
+
+use std::path::Path;
+
+/// Expand `${VAR}` references in every string in a TOML value.
+///
+/// An unset variable is an error rather than an empty string — a silently blank
+/// passphrase is the kind of thing that disables authentication by accident.
+pub fn expand_env_vars(value: &mut toml::Value) -> Result<(), String> {
+    match value {
+        toml::Value::String(s) => {
+            if let Some(expanded) = expand_str(s)? {
+                *s = expanded;
+            }
+        }
+        toml::Value::Table(table) => {
+            for (_, child) in table.iter_mut() {
+                expand_env_vars(child)?;
+            }
+        }
+        toml::Value::Array(items) => {
+            for item in items.iter_mut() {
+                expand_env_vars(item)?;
+            }
+        }
+        _ => {}
+    }
+    Ok(())
+}
+
+/// Expand `${VAR}` in one string; `None` when there was nothing to expand.
+fn expand_str(input: &str) -> Result<Option<String>, String> {
+    if !input.contains("${") {
+        return Ok(None);
+    }
+
+    let mut out = String::with_capacity(input.len());
+    let mut rest = input;
+    while let Some(start) = rest.find("${") {
+        out.push_str(&rest[..start]);
+        let after = &rest[start + 2..];
+        let Some(end) = after.find('}') else {
+            // Unterminated: leave the rest exactly as written.
+            out.push_str(&rest[start..]);
+            return Ok(Some(out));
+        };
+        let name = &after[..end];
+        if name.is_empty() || !name.bytes().all(|b| b.is_ascii_alphanumeric() || b == b'_') {
+            // Not a variable reference; pass it through untouched.
+            out.push_str(&rest[start..start + 2 + end + 1]);
+        } else {
+            let value = std::env::var(name)
+                .map_err(|_| format!("config references unset environment variable ${{{name}}}"))?;
+            out.push_str(&value);
+        }
+        rest = &after[end + 1..];
+    }
+    out.push_str(rest);
+    Ok(Some(out))
+}
+
+/// Read a single secret from a file: the whole file, trimmed.
+pub fn read_secret_file(path: &str, what: &str) -> Result<String, String> {
+    let content = std::fs::read_to_string(path)
+        .map_err(|e| format!("{what}: cannot read secret file {path}: {e}"))?;
+    let secret = content.trim().to_string();
+    if secret.is_empty() {
+        return Err(format!("{what}: secret file {path} is empty"));
+    }
+    warn_if_group_readable(Path::new(path), what);
+    Ok(secret)
+}
+
+/// Read a list of secrets, one per line.  Blank lines and `#` comments are
+/// skipped.
+pub fn read_secret_list_file(path: &str, what: &str) -> Result<Vec<String>, String> {
+    let content = std::fs::read_to_string(path)
+        .map_err(|e| format!("{what}: cannot read secret file {path}: {e}"))?;
+    let secrets: Vec<String> = content
+        .lines()
+        .map(str::trim)
+        .filter(|line| !line.is_empty() && !line.starts_with('#'))
+        .map(str::to_string)
+        .collect();
+    if secrets.is_empty() {
+        return Err(format!("{what}: secret file {path} contains no entries"));
+    }
+    warn_if_group_readable(Path::new(path), what);
+    Ok(secrets)
+}
+
+/// Fill `inline` from `file` when the config used the `*_file` form.
+///
+/// Setting both is an error: which one wins would be a guess.
+pub fn resolve_secret(
+    inline: &mut Option<String>,
+    file: &Option<String>,
+    what: &str,
+) -> Result<(), String> {
+    let Some(path) = file else {
+        return Ok(());
+    };
+    if inline.is_some() {
+        return Err(format!(
+            "{what}: set either the value or its _file form, not both"
+        ));
+    }
+    *inline = Some(read_secret_file(path, what)?);
+    Ok(())
+}
+
+/// Fill a token list from `file` when the config used the `*_file` form.
+pub fn resolve_secret_list(
+    inline: &mut Vec<String>,
+    file: &Option<String>,
+    what: &str,
+) -> Result<(), String> {
+    let Some(path) = file else {
+        return Ok(());
+    };
+    if !inline.is_empty() {
+        return Err(format!(
+            "{what}: set either the value or its _file form, not both"
+        ));
+    }
+    *inline = read_secret_list_file(path, what)?;
+    Ok(())
+}
+
+/// Warn when a file holding secrets is readable beyond its owner.
+///
+/// Advisory only: plenty of valid setups (a dedicated service user, an
+/// immutable image) are fine, so this never fails the load.
+pub fn warn_if_group_readable(path: &Path, what: &str) {
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let Ok(meta) = std::fs::metadata(path) else {
+            return;
+        };
+        let mode = meta.permissions().mode() & 0o077;
+        if mode != 0 {
+            tracing::warn!(
+                "{} is readable by group or others (mode {:o}); it holds secrets ({}). \
+                 Consider: chmod 600 {}",
+                path.display(),
+                meta.permissions().mode() & 0o777,
+                what,
+                path.display()
+            );
+        }
+    }
+    #[cfg(not(unix))]
+    {
+        let _ = (path, what);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::Write;
+
+    #[test]
+    fn test_expand_leaves_plain_strings_alone() {
+        assert_eq!(expand_str("plain").unwrap(), None);
+        assert_eq!(expand_str("TRXRS-%YYYY%.log").unwrap(), None);
+    }
+
+    #[test]
+    fn test_expand_substitutes_variable() {
+        std::env::set_var("TRX_TEST_TOKEN", "s3cret");
+        assert_eq!(
+            expand_str("Bearer ${TRX_TEST_TOKEN}!").unwrap().as_deref(),
+            Some("Bearer s3cret!")
+        );
+    }
+
+    #[test]
+    fn test_expand_errors_on_unset_variable() {
+        let err = expand_str("${TRX_DEFINITELY_NOT_SET_12345}").unwrap_err();
+        assert!(err.contains("unset environment variable"), "{err}");
+    }
+
+    #[test]
+    fn test_expand_passes_through_non_variables() {
+        assert_eq!(
+            expand_str("${not a var}").unwrap().as_deref(),
+            Some("${not a var}")
+        );
+        assert_eq!(
+            expand_str("unterminated ${VAR").unwrap().as_deref(),
+            Some("unterminated ${VAR")
+        );
+    }
+
+    #[test]
+    fn test_expand_walks_nested_tables_and_arrays() {
+        std::env::set_var("TRX_TEST_HOST", "radio.example.com");
+        let mut value: toml::Value = toml::from_str(
+            r#"
+[remote]
+url = "${TRX_TEST_HOST}:4530"
+hosts = ["${TRX_TEST_HOST}"]
+"#,
+        )
+        .unwrap();
+        expand_env_vars(&mut value).unwrap();
+        assert_eq!(
+            value["remote"]["url"].as_str(),
+            Some("radio.example.com:4530")
+        );
+        assert_eq!(
+            value["remote"]["hosts"][0].as_str(),
+            Some("radio.example.com")
+        );
+    }
+
+    fn temp_file(content: &str) -> tempfile::NamedTempFile {
+        let mut f = tempfile::NamedTempFile::new().unwrap();
+        f.write_all(content.as_bytes()).unwrap();
+        f.flush().unwrap();
+        f
+    }
+
+    #[test]
+    fn test_read_secret_file_trims() {
+        let f = temp_file("  hunter2\n");
+        assert_eq!(read_secret_file(path_of(&f), "test").unwrap(), "hunter2");
+    }
+
+    #[test]
+    fn test_read_secret_file_rejects_empty() {
+        let f = temp_file("   \n");
+        assert!(read_secret_file(path_of(&f), "test").is_err());
+    }
+
+    #[test]
+    fn test_read_secret_list_skips_blanks_and_comments() {
+        let f = temp_file("# tokens\nalpha\n\n  beta  \n");
+        assert_eq!(
+            read_secret_list_file(path_of(&f), "test").unwrap(),
+            vec!["alpha".to_string(), "beta".to_string()]
+        );
+    }
+
+    #[test]
+    fn test_resolve_secret_fills_from_file() {
+        let f = temp_file("from-file");
+        let mut inline = None;
+        resolve_secret(&mut inline, &Some(path_of(&f).to_string()), "test").unwrap();
+        assert_eq!(inline.as_deref(), Some("from-file"));
+    }
+
+    #[test]
+    fn test_resolve_secret_rejects_both_forms() {
+        let f = temp_file("from-file");
+        let mut inline = Some("inline".to_string());
+        let err = resolve_secret(&mut inline, &Some(path_of(&f).to_string()), "test").unwrap_err();
+        assert!(err.contains("not both"), "{err}");
+    }
+
+    #[test]
+    fn test_resolve_secret_is_a_no_op_without_file() {
+        let mut inline = Some("inline".to_string());
+        resolve_secret(&mut inline, &None, "test").unwrap();
+        assert_eq!(inline.as_deref(), Some("inline"));
+    }
+
+    #[test]
+    fn test_resolve_secret_list_rejects_both_forms() {
+        let f = temp_file("alpha");
+        let mut inline = vec!["inline".to_string()];
+        let err =
+            resolve_secret_list(&mut inline, &Some(path_of(&f).to_string()), "test").unwrap_err();
+        assert!(err.contains("not both"), "{err}");
+    }
+
+    fn path_of(f: &tempfile::NamedTempFile) -> &str {
+        f.path().to_str().unwrap()
+    }
+}
@@ -19,6 +19,52 @@
 //! would either bloat both binaries with unused fields or require a trait
 //! abstraction that adds complexity without clear benefit.

+use std::net::IpAddr;
+
+/// A socket a component intends to bind, and what it is for.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct BoundSocket {
+    pub addr: IpAddr,
+    pub port: u16,
+    /// Human-readable owner, e.g. `[listen]` or `[frontends.http]`.
+    pub label: String,
+}
+
+impl BoundSocket {
+    pub fn new(addr: IpAddr, port: u16, label: impl Into<String>) -> Self {
+        Self {
+            addr,
+            port,
+            label: label.into(),
+        }
+    }
+}
+
+/// Reject two components trying to bind the same socket.
+///
+/// A wildcard address (`0.0.0.0` / `::`) conflicts with any other address on
+/// the same port, since binding it claims every interface.  Port 0 means "pick
+/// an ephemeral port" and never conflicts.
+pub fn check_socket_conflicts(sockets: &[BoundSocket]) -> Result<(), String> {
+    for (i, a) in sockets.iter().enumerate() {
+        if a.port == 0 {
+            continue;
+        }
+        for b in &sockets[i + 1..] {
+            if b.port != a.port {
+                continue;
+            }
+            if a.addr == b.addr || a.addr.is_unspecified() || b.addr.is_unspecified() {
+                return Err(format!(
+                    "{} and {} would both bind {}:{}",
+                    a.label, b.label, a.addr, a.port
+                ));
+            }
+        }
+    }
+    Ok(())
+}
+
 /// Validate that a log level string is one of the accepted values.
 ///
 /// Returns `Ok(())` when `level` is `None` (defaulting is handled elsewhere)
@@ -53,6 +99,47 @@ pub fn validate_tokens(path: &str, tokens: &[String]) -> Result<(), String> {
 mod tests {
    use super::*;

+    fn sock(addr: &str, port: u16, label: &str) -> BoundSocket {
+        BoundSocket::new(addr.parse().unwrap(), port, label)
+    }
+
+    #[test]
+    fn test_socket_conflicts_detects_exact_duplicate() {
+        let err = check_socket_conflicts(&[
+            sock("127.0.0.1", 8080, "[frontends.http]"),
+            sock("127.0.0.1", 8080, "[frontends.http_json]"),
+        ])
+        .unwrap_err();
+        assert!(err.contains("127.0.0.1:8080"), "unexpected error: {err}");
+    }
+
+    #[test]
+    fn test_socket_conflicts_detects_wildcard_overlap() {
+        assert!(check_socket_conflicts(&[
+            sock("0.0.0.0", 4530, "[listen]"),
+            sock("127.0.0.1", 4530, "[audio]"),
+        ])
+        .is_err());
+    }
+
+    #[test]
+    fn test_socket_conflicts_allows_distinct_addresses() {
+        assert!(check_socket_conflicts(&[
+            sock("127.0.0.1", 4530, "[listen]"),
+            sock("192.168.1.5", 4530, "[audio]"),
+        ])
+        .is_ok());
+    }
+
+    #[test]
+    fn test_socket_conflicts_ignores_ephemeral_ports() {
+        assert!(check_socket_conflicts(&[
+            sock("127.0.0.1", 0, "[frontends.http_json]"),
+            sock("127.0.0.1", 0, "[frontends.http]"),
+        ])
+        .is_ok());
+    }
+
    #[test]
    fn test_validate_log_level_none() {
        assert!(validate_log_level(None).is_ok());
@@ -0,0 +1,263 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Reporting for config keys the deserializer ignored.
+//!
+//! Every config struct is `#[serde(default)]`, so a misspelled key used to be
+//! dropped without a word and the setting silently kept its default.  The
+//! loader now collects the ignored key paths and pairs each with the closest
+//! known key at the same level, so `prot = 9999` reads as a typo instead of
+//! looking like it worked.
+
+use std::collections::BTreeSet;
+use std::fmt;
+
+/// A config key that the deserializer did not recognise.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct UnknownKey {
+    /// Dotted path of the key, e.g. `listen.prot` or `rigs.0.audio.prot`.
+    pub path: String,
+    /// Closest known key at the same level, when one is near enough to suggest.
+    pub suggestion: Option<String>,
+}
+
+impl fmt::Display for UnknownKey {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match &self.suggestion {
+            Some(s) => write!(
+                f,
+                "unknown config key '{}' (did you mean '{}'?)",
+                self.path, s
+            ),
+            None => write!(f, "unknown config key '{}'", self.path),
+        }
+    }
+}
+
+/// Flatten a TOML value into the set of dotted key paths it contains.
+///
+/// Array indices are normalised to `0` so a path inside `[[rigs]]` matches
+/// whichever entry it came from.
+pub fn flatten_paths(value: &toml::Value) -> BTreeSet<String> {
+    let mut paths = BTreeSet::new();
+    walk(value, "", &mut paths);
+    paths
+}
+
+fn walk(value: &toml::Value, prefix: &str, paths: &mut BTreeSet<String>) {
+    let join = |seg: &str| {
+        if prefix.is_empty() {
+            seg.to_string()
+        } else {
+            format!("{prefix}.{seg}")
+        }
+    };
+    match value {
+        toml::Value::Table(table) => {
+            for (key, child) in table {
+                let path = join(key);
+                paths.insert(path.clone());
+                walk(child, &path, paths);
+            }
+        }
+        toml::Value::Array(items) => {
+            // Every entry of an array of tables has the same shape, so collapse
+            // them onto index 0 and let one entry stand for all.
+            for item in items {
+                let path = join("0");
+                walk(item, &path, paths);
+            }
+        }
+        _ => {}
+    }
+}
+
+/// Replace numeric path segments with `0` so array entries compare equal.
+fn normalize(path: &str) -> String {
+    path.split('.')
+        .map(|seg| {
+            if !seg.is_empty() && seg.bytes().all(|b| b.is_ascii_digit()) {
+                "0"
+            } else {
+                seg
+            }
+        })
+        .collect::<Vec<_>>()
+        .join(".")
+}
+
+/// Suggest the closest known key that sits at the same level as `path`.
+///
+/// Returns `None` when nothing is close enough to be worth printing.
+pub fn suggest(path: &str, known: &BTreeSet<String>) -> Option<String> {
+    let normalized = normalize(path);
+    let (parent, leaf) = match normalized.rsplit_once('.') {
+        Some((parent, leaf)) => (parent, leaf),
+        None => ("", normalized.as_str()),
+    };
+
+    // Anything longer than this is a different word, not a typo.
+    let limit = (leaf.chars().count() / 3).clamp(1, 3);
+    let mut best: Option<(usize, &str)> = None;
+
+    for candidate in known {
+        let (cand_parent, cand_leaf) = match candidate.rsplit_once('.') {
+            Some((p, l)) => (p, l),
+            None => ("", candidate.as_str()),
+        };
+        if cand_parent != parent || cand_leaf == leaf {
+            continue;
+        }
+        let distance = edit_distance(leaf, cand_leaf);
+        if distance <= limit && best.is_none_or(|(best_d, _)| distance < best_d) {
+            best = Some((distance, cand_leaf));
+        }
+    }
+
+    best.map(|(_, leaf)| {
+        if parent.is_empty() {
+            leaf.to_string()
+        } else {
+            format!("{parent}.{leaf}")
+        }
+    })
+}
+
+/// Pair each ignored path with a suggestion drawn from `reference`.
+pub fn describe(paths: &[String], reference: &toml::Value) -> Vec<UnknownKey> {
+    let known = flatten_paths(reference);
+    paths
+        .iter()
+        .map(|path| UnknownKey {
+            path: path.clone(),
+            suggestion: suggest(path, &known),
+        })
+        .collect()
+}
+
+/// Optimal string alignment distance: Levenshtein plus transpositions, so the
+/// common `port` → `prot` slip counts as one mistake rather than two.
+fn edit_distance(a: &str, b: &str) -> usize {
+    let a: Vec<char> = a.chars().collect();
+    let b: Vec<char> = b.chars().collect();
+    if a.is_empty() {
+        return b.len();
+    }
+    if b.is_empty() {
+        return a.len();
+    }
+
+    let mut rows = vec![vec![0usize; b.len() + 1]; a.len() + 1];
+    for (i, row) in rows.iter_mut().enumerate() {
+        row[0] = i;
+    }
+    for (j, cell) in rows[0].iter_mut().enumerate() {
+        *cell = j;
+    }
+
+    for i in 1..=a.len() {
+        for j in 1..=b.len() {
+            let cost = usize::from(a[i - 1] != b[j - 1]);
+            let mut best = (rows[i - 1][j] + 1)
+                .min(rows[i][j - 1] + 1)
+                .min(rows[i - 1][j - 1] + cost);
+            if i > 1 && j > 1 && a[i - 1] == b[j - 2] && a[i - 2] == b[j - 1] {
+                best = best.min(rows[i - 2][j - 2] + 1);
+            }
+            rows[i][j] = best;
+        }
+    }
+    rows[a.len()][b.len()]
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn reference() -> toml::Value {
+        toml::from_str(
+            r#"
+[general]
+callsign = "N0CALL"
+log_level = "info"
+
+[listen]
+enabled = true
+port = 4530
+
+[[rigs]]
+id = "hf"
+[rigs.audio]
+port = 4531
+sample_rate = 48000
+"#,
+        )
+        .unwrap()
+    }
+
+    #[test]
+    fn test_flatten_collects_nested_paths() {
+        let paths = flatten_paths(&reference());
+        assert!(paths.contains("general.callsign"));
+        assert!(paths.contains("listen.port"));
+        assert!(paths.contains("rigs.0.audio.sample_rate"));
+    }
+
+    #[test]
+    fn test_suggest_finds_close_sibling() {
+        let known = flatten_paths(&reference());
+        assert_eq!(
+            suggest("listen.prot", &known).as_deref(),
+            Some("listen.port")
+        );
+    }
+
+    #[test]
+    fn test_suggest_inside_array_entry() {
+        let known = flatten_paths(&reference());
+        assert_eq!(
+            suggest("rigs.1.audio.prot", &known).as_deref(),
+            Some("rigs.0.audio.port")
+        );
+    }
+
+    #[test]
+    fn test_suggest_ignores_distant_names() {
+        let known = flatten_paths(&reference());
+        assert_eq!(suggest("listen.bananas", &known), None);
+    }
+
+    #[test]
+    fn test_suggest_does_not_cross_levels() {
+        let known = flatten_paths(&reference());
+        // `port` exists under [listen], but not under [general].
+        assert_eq!(suggest("general.port", &known), None);
+    }
+
+    #[test]
+    fn test_describe_formats_message() {
+        let described = describe(&["listen.prot".to_string()], &reference());
+        assert_eq!(
+            described[0].to_string(),
+            "unknown config key 'listen.prot' (did you mean 'listen.port'?)"
+        );
+    }
+
+    #[test]
+    fn test_describe_without_suggestion() {
+        let described = describe(&["listen.bananas".to_string()], &reference());
+        assert_eq!(
+            described[0].to_string(),
+            "unknown config key 'listen.bananas'"
+        );
+    }
+
+    #[test]
+    fn test_edit_distance_counts_transposition_once() {
+        assert_eq!(edit_distance("port", "prot"), 1);
+        assert_eq!(edit_distance("port", "port"), 0);
+        assert_eq!(edit_distance("", "port"), 4);
+        assert_eq!(edit_distance("sample_rat", "sample_rate"), 1);
+    }
+}
@@ -0,0 +1,173 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Parsing for the `host:port` endpoint URLs used by the client's `[[remotes]]`
+//! and `[frontends.audio]` settings.
+//!
+//! These live next to the config structs because validation needs them; the
+//! client re-exports them for its connection code.
+
+/// Default port for the server's JSON control listener.
+pub const DEFAULT_REMOTE_PORT: u16 = 4530;
+/// Default port for the server's Opus audio listener.
+pub const DEFAULT_AUDIO_PORT: u16 = 4531;
+
+/// A resolved `host:port` pair.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct RemoteEndpoint {
+    pub host: String,
+    pub port: u16,
+}
+
+impl RemoteEndpoint {
+    /// Format as a connect string, bracketing bare IPv6 hosts.
+    pub fn connect_addr(&self) -> String {
+        if self.host.contains(':') && !self.host.starts_with('[') {
+            format!("[{}]:{}", self.host, self.port)
+        } else {
+            format!("{}:{}", self.host, self.port)
+        }
+    }
+}
+
+/// Parse a remote control URL, defaulting to port 4530.
+pub fn parse_remote_url(url: &str) -> Result<RemoteEndpoint, String> {
+    parse_endpoint_url(url, DEFAULT_REMOTE_PORT, "remote")
+}
+
+/// Parse an audio stream URL, defaulting to port 4531.
+pub fn parse_audio_url(url: &str) -> Result<RemoteEndpoint, String> {
+    parse_endpoint_url(url, DEFAULT_AUDIO_PORT, "audio")
+}
+
+fn parse_endpoint_url(url: &str, default_port: u16, kind: &str) -> Result<RemoteEndpoint, String> {
+    let trimmed = url.trim();
+    if trimmed.is_empty() {
+        return Err(format!("{kind} url is empty"));
+    }
+
+    let addr = trimmed
+        .strip_prefix("tcp://")
+        .or_else(|| trimmed.strip_prefix("http-json://"))
+        .or_else(|| trimmed.strip_prefix("audio://"))
+        .unwrap_or(trimmed);
+
+    parse_host_port(addr, default_port, kind)
+}
+
+fn parse_host_port(input: &str, default_port: u16, kind: &str) -> Result<RemoteEndpoint, String> {
+    if let Some(rest) = input.strip_prefix('[') {
+        let closing = rest
+            .find(']')
+            .ok_or_else(|| format!("invalid {kind} url: missing closing ']' for IPv6 host"))?;
+        let host = &rest[..closing];
+        let remainder = &rest[closing + 1..];
+        if host.is_empty() {
+            return Err(format!("invalid {kind} url: host is empty"));
+        }
+        let port = if remainder.is_empty() {
+            default_port
+        } else if let Some(port_str) = remainder.strip_prefix(':') {
+            parse_port(port_str, kind)?
+        } else {
+            return Err(format!("invalid {kind} url: expected ':<port>' after ']'"));
+        };
+        return Ok(RemoteEndpoint {
+            host: host.to_string(),
+            port,
+        });
+    }
+
+    if input.contains(':') {
+        if input.matches(':').count() > 1 {
+            return Err(format!(
+                "invalid {kind} url: IPv6 host must be bracketed like [::1]:4532"
+            ));
+        }
+        let (host, port_str) = input
+            .rsplit_once(':')
+            .ok_or_else(|| format!("invalid {kind} url: expected host:port"))?;
+        if host.is_empty() {
+            return Err(format!("invalid {kind} url: host is empty"));
+        }
+        return Ok(RemoteEndpoint {
+            host: host.to_string(),
+            port: parse_port(port_str, kind)?,
+        });
+    }
+
+    Ok(RemoteEndpoint {
+        host: input.to_string(),
+        port: default_port,
+    })
+}
+
+fn parse_port(port_str: &str, kind: &str) -> Result<u16, String> {
+    let port: u16 = port_str
+        .parse()
+        .map_err(|_| format!("invalid {kind} port: '{port_str}'"))?;
+    if port == 0 {
+        return Err(format!("invalid {kind} port: 0"));
+    }
+    Ok(port)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_remote_url_defaults_port() {
+        let ep = parse_remote_url("example.com").unwrap();
+        assert_eq!(ep.host, "example.com");
+        assert_eq!(ep.port, DEFAULT_REMOTE_PORT);
+    }
+
+    #[test]
+    fn test_parse_audio_url_defaults_port() {
+        let ep = parse_audio_url("example.com").unwrap();
+        assert_eq!(ep.port, DEFAULT_AUDIO_PORT);
+    }
+
+    #[test]
+    fn test_parse_strips_schemes() {
+        for url in &[
+            "tcp://host:9000",
+            "http-json://host:9000",
+            "audio://host:9000",
+        ] {
+            let ep = parse_remote_url(url).unwrap();
+            assert_eq!(ep.host, "host");
+            assert_eq!(ep.port, 9000);
+        }
+    }
+
+    #[test]
+    fn test_parse_bracketed_ipv6() {
+        let ep = parse_remote_url("[::1]:4532").unwrap();
+        assert_eq!(ep.host, "::1");
+        assert_eq!(ep.port, 4532);
+        assert_eq!(ep.connect_addr(), "[::1]:4532");
+    }
+
+    #[test]
+    fn test_parse_rejects_unbracketed_ipv6() {
+        assert!(parse_remote_url("::1:4532").is_err());
+    }
+
+    #[test]
+    fn test_parse_rejects_empty_host() {
+        assert!(parse_remote_url(":4530").is_err());
+    }
+
+    #[test]
+    fn test_parse_rejects_zero_port() {
+        assert!(parse_remote_url("host:0").is_err());
+    }
+
+    #[test]
+    fn test_parse_rejects_empty_url() {
+        assert!(parse_remote_url("   ").is_err());
+    }
+}
@@ -15,7 +15,9 @@ path = "src/main.rs"
 clap = { workspace = true, features = ["derive"] }
 dialoguer = "0.11"
 tokio-serial = { workspace = true }
+toml = "0.8"
 toml_edit = "0.22"
+trx-config = { path = "../trx-config" }

 [dev-dependencies]
 tempfile = "3"
@@ -2,80 +2,37 @@
 //
 // SPDX-License-Identifier: GPL-2.0-or-later

+//! `trx-configurator --check`: run a config file through the same loader and
+//! validators the binaries use.
+//!
+//! This used to be a second, hand-maintained implementation — lists of known
+//! keys and a handful of re-implemented range checks — which drifted out of
+//! date as soon as a field was added.  It now defers entirely to `trx-config`,
+//! so a config that checks clean here is one the binaries will accept.
+
 use std::fmt::Write as _;
 use std::path::Path;

-use toml_edit::DocumentMut;
+use trx_config::{ClientConfig, ServerConfig};

-/// Known top-level keys for a standalone server config.
-const SERVER_KEYS: &[&str] = &[
-    "general",
+/// Top-level keys that only appear in a server config.  Used solely to guess
+/// what a section-less file is meant to be; the real key checking is done by
+/// the loader.
+const SERVER_MARKERS: &[&str] = &[
    "rig",
    "rigs",
-    "behavior",
    "listen",
-    "audio",
+    "behavior",
    "sdr",
    "pskreporter",
    "aprsfi",
    "decode_logs",
+    "timeouts",
+    "audio",
 ];

-/// Known top-level keys for a standalone client config.
-const CLIENT_KEYS: &[&str] = &["general", "remote", "remotes", "frontends"];
-
-/// Known top-level keys for a combined trx-rs.toml.
-const COMBINED_KEYS: &[&str] = &["trx-server", "trx-client"];
-
-/// Known sub-keys within [general] (server).
-const SERVER_GENERAL_KEYS: &[&str] = &["callsign", "log_level", "latitude", "longitude"];
-
-/// Known sub-keys within [general] (client).
-const CLIENT_GENERAL_KEYS: &[&str] = &[
-    "callsign",
-    "log_level",
-    "website_url",
-    "website_name",
-    "ais_vessel_url_base",
-];
-
-/// Known sub-keys within [rig].
-const RIG_KEYS: &[&str] = &["model", "initial_freq_hz", "initial_mode", "access"];
-
-/// Known sub-keys within [rig.access].
-const ACCESS_KEYS: &[&str] = &["type", "port", "baud", "host", "tcp_port", "args"];
-
-/// Known sub-keys within [listen].
-const LISTEN_KEYS: &[&str] = &["enabled", "listen", "port", "auth"];
-
-/// Known sub-keys within [audio] (server).
-const AUDIO_KEYS: &[&str] = &[
-    "enabled",
-    "listen",
-    "port",
-    "rx_enabled",
-    "tx_enabled",
-    "device",
-    "sample_rate",
-    "channels",
-    "frame_duration_ms",
-    "bitrate_bps",
-];
-
-/// Known sub-keys within [behavior].
-const BEHAVIOR_KEYS: &[&str] = &[
-    "poll_interval_ms",
-    "poll_interval_tx_ms",
-    "max_retries",
-    "retry_base_delay_ms",
-    "vfo_prime",
-];
-
-/// Known sub-keys within [remote].
-const REMOTE_KEYS: &[&str] = &["url", "rig_id", "auth", "poll_interval_ms"];
-
-/// Known sub-keys within [frontends].
-const FRONTENDS_KEYS: &[&str] = &["http", "rigctl", "http_json", "audio"];
+/// Top-level keys that only appear in a client config.
+const CLIENT_MARKERS: &[&str] = &["remote", "remotes", "frontends"];

 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 enum DetectedType {
@@ -100,49 +57,38 @@ pub fn check_file(path: &Path) -> Result<String, String> {
    let content = std::fs::read_to_string(path)
        .map_err(|e| format!("Failed to read {}: {}", path.display(), e))?;

-    // Step 1: TOML syntax check
-    let doc: DocumentMut = content
-        .parse()
+    let table: toml::Table = toml::from_str(&content)
        .map_err(|e| format!("{}: TOML syntax error: {}", path.display(), e))?;

+    let detected = detect_type(&table);
+
    let mut report = String::new();
    let mut warnings: Vec<String> = Vec::new();
    let mut errors: Vec<String> = Vec::new();

-    let table = doc.as_table();
-
-    // Step 2: Detect config type
-    let detected = detect_type(table);
    writeln!(report, "{}: valid TOML", path.display()).unwrap();
    writeln!(report, "  Detected type: {}", detected).unwrap();

-    // Step 3: Structural validation
    match detected {
-        DetectedType::Server => {
-            check_unknown_keys(table, SERVER_KEYS, "", &mut warnings);
-            check_server_sections(table, "", &mut warnings, &mut errors);
-        }
-        DetectedType::Client => {
-            check_unknown_keys(table, CLIENT_KEYS, "", &mut warnings);
-            check_client_sections(table, "", &mut warnings, &mut errors);
-        }
+        DetectedType::Server => check_server(path, &mut warnings, &mut errors),
+        DetectedType::Client => check_client(path, &mut warnings, &mut errors),
        DetectedType::Combined => {
-            check_unknown_keys(table, COMBINED_KEYS, "", &mut warnings);
-            if let Some(server) = table.get("trx-server").and_then(|v| v.as_table()) {
-                check_unknown_keys(server, SERVER_KEYS, "[trx-server].", &mut warnings);
-                check_server_sections(server, "[trx-server].", &mut warnings, &mut errors);
+            if table.contains_key("trx-server") {
+                check_server(path, &mut warnings, &mut errors);
            }
-            if let Some(client) = table.get("trx-client").and_then(|v| v.as_table()) {
-                check_unknown_keys(client, CLIENT_KEYS, "[trx-client].", &mut warnings);
-                check_client_sections(client, "[trx-client].", &mut warnings, &mut errors);
+            if table.contains_key("trx-client") {
+                check_client(path, &mut warnings, &mut errors);
            }
        }
        DetectedType::Unknown => {
-            warnings.push("Could not detect config type. Expected server, client, or combined (trx-rs.toml) layout.".to_string());
+            warnings.push(
+                "Could not detect config type. Expected server, client, or combined \
+                 (trx-rs.toml) layout."
+                    .to_string(),
+            );
        }
    }

-    // Step 4: Format report
    for w in &warnings {
        writeln!(report, "  warning: {}", w).unwrap();
    }
@@ -169,23 +115,54 @@ pub fn check_file(path: &Path) -> Result<String, String> {
    }
 }

-fn detect_type(table: &toml_edit::Table) -> DetectedType {
+fn check_server(path: &Path, warnings: &mut Vec<String>, errors: &mut Vec<String>) {
+    match ServerConfig::load_from_file(path) {
+        Ok(loaded) => {
+            warnings.extend(loaded.unknown_keys.iter().map(|k| k.to_string()));
+            if let Err(e) = loaded.config.validate() {
+                errors.push(format!("[trx-server] {}", e));
+            }
+            errors.extend(
+                loaded
+                    .config
+                    .validate_sdr()
+                    .into_iter()
+                    .map(|e| format!("[trx-server] {}", e)),
+            );
+        }
+        Err(e) => errors.push(e.to_string()),
+    }
+}
+
+fn check_client(path: &Path, warnings: &mut Vec<String>, errors: &mut Vec<String>) {
+    match ClientConfig::load_from_file(path) {
+        Ok(loaded) => {
+            warnings.extend(loaded.unknown_keys.iter().map(|k| k.to_string()));
+            if let Err(e) = loaded.config.validate() {
+                errors.push(format!("[trx-client] {}", e));
+            }
+        }
+        Err(e) => errors.push(e.to_string()),
+    }
+}
+
+fn detect_type(table: &toml::Table) -> DetectedType {
    if table.contains_key("trx-server") || table.contains_key("trx-client") {
        return DetectedType::Combined;
    }
-    let keys: Vec<&str> = table.iter().map(|(k, _)| k).collect();
+    let keys: Vec<&str> = table.keys().map(|k| k.as_str()).collect();

-    let server_score = keys.iter().filter(|k| SERVER_KEYS.contains(k)).count();
-    let client_score = keys.iter().filter(|k| CLIENT_KEYS.contains(k)).count();
-
-    // Use distinguishing keys to break ties
-    if keys.contains(&"rig") || keys.contains(&"rigs") || keys.contains(&"listen") {
+    // Distinguishing keys first, then a simple majority.
+    if keys.iter().any(|k| ["rig", "rigs", "listen"].contains(k)) {
        return DetectedType::Server;
    }
-    if keys.contains(&"remote") || keys.contains(&"remotes") || keys.contains(&"frontends") {
+    if keys.iter().any(|k| CLIENT_MARKERS.contains(k)) {
        return DetectedType::Client;
    }

+    let server_score = keys.iter().filter(|k| SERVER_MARKERS.contains(k)).count();
+    let client_score = keys.iter().filter(|k| CLIENT_MARKERS.contains(k)).count();
+
    if server_score > client_score {
        DetectedType::Server
    } else if client_score > server_score {
@@ -197,194 +174,6 @@ fn detect_type(table: &toml_edit::Table) -> DetectedType {
    }
 }

-fn check_unknown_keys(
-    table: &toml_edit::Table,
-    known: &[&str],
-    prefix: &str,
-    warnings: &mut Vec<String>,
-) {
-    for (key, _) in table.iter() {
-        if !known.contains(&key) {
-            warnings.push(format!("{}unknown key '{}'", prefix, key));
-        }
-    }
-}
-
-fn check_server_sections(
-    table: &toml_edit::Table,
-    prefix: &str,
-    warnings: &mut Vec<String>,
-    errors: &mut Vec<String>,
-) {
-    if let Some(general) = table.get("general").and_then(|v| v.as_table()) {
-        check_unknown_keys(
-            general,
-            SERVER_GENERAL_KEYS,
-            &format!("{}[general].", prefix),
-            warnings,
-        );
-        validate_log_level(general, &format!("{}[general]", prefix), errors);
-        validate_coordinates(general, &format!("{}[general]", prefix), errors);
-    }
-
-    if let Some(rig) = table.get("rig").and_then(|v| v.as_table()) {
-        check_unknown_keys(rig, RIG_KEYS, &format!("{}[rig].", prefix), warnings);
-        if let Some(access) = rig.get("access").and_then(|v| v.as_table()) {
-            check_unknown_keys(
-                access,
-                ACCESS_KEYS,
-                &format!("{}[rig.access].", prefix),
-                warnings,
-            );
-            validate_access(access, &format!("{}[rig.access]", prefix), errors);
-        }
-    }
-
-    if let Some(listen) = table.get("listen").and_then(|v| v.as_table()) {
-        check_unknown_keys(
-            listen,
-            LISTEN_KEYS,
-            &format!("{}[listen].", prefix),
-            warnings,
-        );
-        validate_port(listen, "port", &format!("{}[listen]", prefix), errors);
-    }
-
-    if let Some(audio) = table.get("audio").and_then(|v| v.as_table()) {
-        check_unknown_keys(audio, AUDIO_KEYS, &format!("{}[audio].", prefix), warnings);
-        validate_port(audio, "port", &format!("{}[audio]", prefix), errors);
-    }
-
-    if let Some(behavior) = table.get("behavior").and_then(|v| v.as_table()) {
-        check_unknown_keys(
-            behavior,
-            BEHAVIOR_KEYS,
-            &format!("{}[behavior].", prefix),
-            warnings,
-        );
-    }
-}
-
-fn check_client_sections(
-    table: &toml_edit::Table,
-    prefix: &str,
-    warnings: &mut Vec<String>,
-    errors: &mut Vec<String>,
-) {
-    if let Some(general) = table.get("general").and_then(|v| v.as_table()) {
-        check_unknown_keys(
-            general,
-            CLIENT_GENERAL_KEYS,
-            &format!("{}[general].", prefix),
-            warnings,
-        );
-        validate_log_level(general, &format!("{}[general]", prefix), errors);
-    }
-
-    if let Some(remote) = table.get("remote").and_then(|v| v.as_table()) {
-        check_unknown_keys(
-            remote,
-            REMOTE_KEYS,
-            &format!("{}[remote].", prefix),
-            warnings,
-        );
-    }
-
-    if let Some(frontends) = table.get("frontends").and_then(|v| v.as_table()) {
-        check_unknown_keys(
-            frontends,
-            FRONTENDS_KEYS,
-            &format!("{}[frontends].", prefix),
-            warnings,
-        );
-        if let Some(http) = frontends.get("http").and_then(|v| v.as_table()) {
-            validate_port(http, "port", &format!("{}[frontends.http]", prefix), errors);
-        }
-        if let Some(rigctl) = frontends.get("rigctl").and_then(|v| v.as_table()) {
-            validate_port(
-                rigctl,
-                "port",
-                &format!("{}[frontends.rigctl]", prefix),
-                errors,
-            );
-        }
-    }
-}
-
-// ── Value validators ────────────────────────────────────────────────────
-
-fn validate_log_level(table: &toml_edit::Table, context: &str, errors: &mut Vec<String>) {
-    if let Some(level) = table.get("log_level").and_then(|v| v.as_str()) {
-        if !["trace", "debug", "info", "warn", "error"].contains(&level) {
-            errors.push(format!(
-                "{}.log_level '{}' is invalid (expected: trace, debug, info, warn, error)",
-                context, level
-            ));
-        }
-    }
-}
-
-fn validate_coordinates(table: &toml_edit::Table, context: &str, errors: &mut Vec<String>) {
-    if let Some(lat) = table
-        .get("latitude")
-        .and_then(|v| v.as_float().or_else(|| v.as_integer().map(|i| i as f64)))
-    {
-        if !(-90.0..=90.0).contains(&lat) {
-            errors.push(format!(
-                "{}.latitude {} is out of range (-90..90)",
-                context, lat
-            ));
-        }
-    }
-    if let Some(lon) = table
-        .get("longitude")
-        .and_then(|v| v.as_float().or_else(|| v.as_integer().map(|i| i as f64)))
-    {
-        if !(-180.0..=180.0).contains(&lon) {
-            errors.push(format!(
-                "{}.longitude {} is out of range (-180..180)",
-                context, lon
-            ));
-        }
-    }
-
-    let has_lat = table.contains_key("latitude");
-    let has_lon = table.contains_key("longitude");
-    if has_lat != has_lon {
-        errors.push(format!(
-            "{}: latitude and longitude must be set together or both omitted",
-            context
-        ));
-    }
-}
-
-fn validate_port(table: &toml_edit::Table, key: &str, context: &str, errors: &mut Vec<String>) {
-    if let Some(port) = table.get(key).and_then(|v| v.as_integer()) {
-        if let Some(enabled) = table.get("enabled").and_then(|v| v.as_bool()) {
-            if enabled && port <= 0 {
-                errors.push(format!("{}.{} must be > 0 when enabled", context, key));
-            }
-        }
-        if !(0..=65535).contains(&port) {
-            errors.push(format!(
-                "{}.{} {} is out of range (0..65535)",
-                context, key, port
-            ));
-        }
-    }
-}
-
-fn validate_access(table: &toml_edit::Table, context: &str, errors: &mut Vec<String>) {
-    if let Some(access_type) = table.get("type").and_then(|v| v.as_str()) {
-        if !["serial", "tcp", "sdr"].contains(&access_type) {
-            errors.push(format!(
-                "{}.type '{}' is invalid (expected: serial, tcp, sdr)",
-                context, access_type
-            ));
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -418,8 +207,7 @@ enabled = true
 port = 4530
 "#,
        );
-        assert!(result.is_ok());
-        let report = result.unwrap();
+        let report = result.expect("expected a clean report");
        assert!(report.contains("Detected type: server"));
        assert!(report.contains("No issues found"));
    }
@@ -432,41 +220,40 @@ port = 4530
 callsign = "W1AW"

 [remote]
-url = "localhost:4530"
+url = "192.168.1.10:4530"

 [frontends.http]
 enabled = true
 port = 8080
 "#,
        );
-        assert!(result.is_ok());
-        let report = result.unwrap();
+        let report = result.expect("expected a clean report");
        assert!(report.contains("Detected type: client"));
+        assert!(report.contains("No issues found"));
    }

    #[test]
    fn test_valid_combined_config() {
        let result = check_toml(
            r#"
-[trx-server.general]
-callsign = "W1AW"
-
-[trx-client.general]
-callsign = "W1AW"
+[trx-server.rig]
+model = "ft817"
+[trx-server.rig.access]
+type = "serial"
+port = "/dev/ttyUSB0"
+baud = 9600

 [trx-client.remote]
-url = "localhost:4530"
+url = "127.0.0.1:4530"
 "#,
        );
-        assert!(result.is_ok());
-        let report = result.unwrap();
+        let report = result.expect("expected a clean report");
        assert!(report.contains("Detected type: combined"));
    }

    #[test]
    fn test_invalid_toml_syntax() {
-        let result = check_toml("this is not [valid toml");
-        assert!(result.is_err());
+        let result = check_toml("[general\ncallsign = \"W1AW\"\n");
        assert!(result.unwrap_err().contains("TOML syntax error"));
    }

@@ -474,19 +261,22 @@ url = "localhost:4530"
    fn test_unknown_key_warning() {
        let result = check_toml(
            r#"
-[general]
-callsign = "W1AW"
-
 [rig]
 model = "ft817"
+[rig.access]
+type = "serial"
+port = "/dev/ttyUSB0"
+baud = 9600

-[bogus_section]
-foo = "bar"
+[listen]
+prot = 4530
 "#,
        );
-        assert!(result.is_ok());
-        let report = result.unwrap();
-        assert!(report.contains("unknown key 'bogus_section'"));
+        let report = result.expect("unknown keys are warnings, not errors");
+        assert!(
+            report.contains("unknown config key 'listen.prot' (did you mean 'listen.port'?)"),
+            "unexpected report: {report}"
+        );
    }

    #[test]
@@ -498,11 +288,13 @@ log_level = "verbose"

 [rig]
 model = "ft817"
+[rig.access]
+type = "serial"
+port = "/dev/ttyUSB0"
+baud = 9600
 "#,
        );
-        assert!(result.is_err());
-        let report = result.unwrap_err();
-        assert!(report.contains("log_level 'verbose' is invalid"));
+        assert!(result.unwrap_err().contains("log_level"));
    }

    #[test]
@@ -510,15 +302,17 @@ model = "ft817"
        let result = check_toml(
            r#"
 [general]
-latitude = 45.0
+latitude = 52.0

 [rig]
 model = "ft817"
+[rig.access]
+type = "serial"
+port = "/dev/ttyUSB0"
+baud = 9600
 "#,
        );
-        assert!(result.is_err());
-        let report = result.unwrap_err();
-        assert!(report.contains("latitude and longitude must be set together"));
+        assert!(result.unwrap_err().contains("longitude"));
    }

    #[test]
@@ -526,16 +320,18 @@ model = "ft817"
        let result = check_toml(
            r#"
 [general]
-latitude = 95.0
+latitude = 120.0
 longitude = 10.0

 [rig]
 model = "ft817"
+[rig.access]
+type = "serial"
+port = "/dev/ttyUSB0"
+baud = 9600
 "#,
        );
-        assert!(result.is_err());
-        let report = result.unwrap_err();
-        assert!(report.contains("latitude 95 is out of range"));
+        assert!(result.unwrap_err().contains("latitude"));
    }

    #[test]
@@ -547,10 +343,31 @@ model = "ft817"

 [rig.access]
 type = "usb"
+port = "/dev/ttyUSB0"
+baud = 9600
 "#,
        );
-        assert!(result.is_err());
-        let report = result.unwrap_err();
-        assert!(report.contains("type 'usb' is invalid"));
+        assert!(result.unwrap_err().contains("access"));
+    }
+
+    /// The old checker only knew a fixed list of top-level keys and a few range
+    /// rules, so it passed configs the server rejects at startup.
+    #[test]
+    fn test_catches_errors_the_key_list_checker_missed() {
+        let result = check_toml(
+            r#"
+[rig]
+model = "ft817"
+[rig.access]
+type = "serial"
+port = "/dev/ttyUSB0"
+baud = 9600
+
+[audio]
+enabled = true
+frame_duration_ms = 7
+"#,
+        );
+        assert!(result.unwrap_err().contains("frame_duration_ms"));
    }
 }
@@ -211,10 +211,13 @@ pub fn build_server(general: ServerGeneral, rig: RigSetup, listen: ListenSetup)
    let mut doc = DocumentMut::new();
    doc.decor_mut()
        .set_prefix("# trx-server configuration\n# Generated by trx-configurator\n");
-    let tables = build_server_tables(general, rig, listen);
-    for (key, item) in tables.iter() {
-        doc.insert(key, item.clone());
-    }
+    // Emit the sectioned shape (`[trx-server]`) that trx-server writes with
+    // --print-config, so a generated file can be dropped into a combined
+    // trx-rs.toml unchanged.
+    doc.insert(
+        "trx-server",
+        Item::Table(build_server_tables(general, rig, listen)),
+    );
    doc
 }

@@ -350,10 +353,10 @@ pub fn build_client(
    let mut doc = DocumentMut::new();
    doc.decor_mut()
        .set_prefix("# trx-client configuration\n# Generated by trx-configurator\n");
-    let tables = build_client_tables(general, remote, frontends);
-    for (key, item) in tables.iter() {
-        doc.insert(key, item.clone());
-    }
+    doc.insert(
+        "trx-client",
+        Item::Table(build_client_tables(general, remote, frontends)),
+    );
    doc
 }

@@ -453,3 +456,60 @@ pub fn write_file(doc: &DocumentMut, path: &Path) -> Result<(), String> {
    println!("Wrote {}", path.display());
    Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use trx_config::{ClientConfig, ServerConfig};
+
+    fn write_temp(doc: &DocumentMut) -> tempfile::NamedTempFile {
+        let file = tempfile::Builder::new().suffix(".toml").tempfile().unwrap();
+        std::fs::write(file.path(), doc.to_string()).unwrap();
+        file
+    }
+
+    /// The wizard used to emit root-level `[general]` / `[rig]` tables while the
+    /// loader demanded a `[trx-server]` section, so every generated standalone
+    /// config was rejected by the binary it was generated for.
+    #[test]
+    fn test_generated_server_config_loads_and_validates() {
+        let file = write_temp(&build_default(ConfigType::Server));
+        let cfg = ServerConfig::load_from_file(file.path())
+            .expect("generated config must load")
+            .config;
+        cfg.validate().expect("generated config must validate");
+        assert_eq!(cfg.rig.model.as_deref(), Some("ft817"));
+        assert_eq!(cfg.listen.port, 4530);
+    }
+
+    #[test]
+    fn test_generated_client_config_loads_and_validates() {
+        let file = write_temp(&build_default(ConfigType::Client));
+        let cfg = ClientConfig::load_from_file(file.path())
+            .expect("generated config must load")
+            .config;
+        cfg.validate().expect("generated config must validate");
+        assert_eq!(cfg.remote.url.as_deref(), Some("localhost:4530"));
+    }
+
+    #[test]
+    fn test_generated_combined_config_loads_both_sections() {
+        let file = write_temp(&build_default(ConfigType::Combined));
+        let server = ServerConfig::load_from_file(file.path())
+            .expect("server section must load")
+            .config;
+        server.validate().expect("server section must validate");
+        let client = ClientConfig::load_from_file(file.path())
+            .expect("client section must load")
+            .config;
+        client.validate().expect("client section must validate");
+    }
+
+    #[test]
+    fn test_generated_docs_are_sectioned() {
+        let doc = build_default(ConfigType::Server);
+        assert!(doc.as_table().contains_key("trx-server"));
+        let doc = build_default(ConfigType::Client);
+        assert!(doc.as_table().contains_key("trx-client"));
+    }
+}
@@ -17,3 +17,4 @@ uuid = { workspace = true }
 ts-rs = { version = "12.0.1", features = ["uuid-impl"] }
 sgp4 = "2"
 reqwest = { version = "0.12", default-features = false, features = ["rustls-tls"] }
+base64 = "0.22"
@@ -19,6 +19,7 @@ pub mod command;
 pub mod controller;
 pub mod request;
 pub mod response;
+pub mod spectrum_wire;
 pub mod state;

 /// How this backend communicates with the rig.
@@ -0,0 +1,124 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+//! Compact wire encoding for spectrum bins.
+//!
+//! Bins are dBFS magnitudes, and the web UI has always drawn them from `i8`
+//! values — the SSE hop to the browser quantizes and base64-encodes them. The
+//! server→client hop, which is the one that crosses the operator's network,
+//! used to send the same information as a JSON array of `f32`: around ten bytes
+//! per bin instead of one, or roughly 10 KB per 1024-bin frame.
+//!
+//! Bins therefore travel as base64-encoded `i8` dBFS, about an eighth of the
+//! size, at a resolution the display already rounds to. Decoding still accepts
+//! the old array form, so a new client can read an older server.
+
+use base64::engine::general_purpose::STANDARD as BASE64;
+use base64::Engine as _;
+use serde::de::{SeqAccess, Visitor};
+use serde::{Deserializer, Serializer};
+use std::fmt;
+
+/// Quantize to whole dBFS and encode as base64.
+pub fn serialize<S: Serializer>(bins: &[f32], serializer: S) -> Result<S::Ok, S::Error> {
+    let quantized: Vec<u8> = bins
+        .iter()
+        .map(|&db| {
+            let clamped = if db.is_finite() { db } else { -128.0 };
+            clamped.round().clamp(-128.0, 127.0) as i8 as u8
+        })
+        .collect();
+    serializer.serialize_str(&BASE64.encode(quantized))
+}
+
+/// Decode base64 bins, or a plain array of numbers from an older server.
+pub fn deserialize<'de, D: Deserializer<'de>>(deserializer: D) -> Result<Vec<f32>, D::Error> {
+    deserializer.deserialize_any(BinsVisitor)
+}
+
+struct BinsVisitor;
+
+impl<'de> Visitor<'de> for BinsVisitor {
+    type Value = Vec<f32>;
+
+    fn expecting(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str("base64-encoded i8 dBFS bins, or an array of numbers")
+    }
+
+    fn visit_str<E: serde::de::Error>(self, value: &str) -> Result<Self::Value, E> {
+        let bytes = BASE64
+            .decode(value)
+            .map_err(|e| E::custom(format!("invalid base64 spectrum bins: {e}")))?;
+        Ok(bytes.into_iter().map(|byte| byte as i8 as f32).collect())
+    }
+
+    fn visit_seq<A: SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
+        let mut bins = Vec::with_capacity(seq.size_hint().unwrap_or(1024));
+        while let Some(value) = seq.next_element::<f32>()? {
+            bins.push(value);
+        }
+        Ok(bins)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use serde::{Deserialize, Serialize};
+
+    #[derive(Debug, Serialize, Deserialize, PartialEq)]
+    struct Frame {
+        #[serde(with = "super")]
+        bins: Vec<f32>,
+    }
+
+    #[test]
+    fn test_round_trip_quantizes_to_whole_db() {
+        let frame = Frame {
+            bins: vec![-73.4, -20.6, 0.0, -120.2],
+        };
+        let json = serde_json::to_string(&frame).unwrap();
+        let back: Frame = serde_json::from_str(&json).unwrap();
+        assert_eq!(back.bins, vec![-73.0, -21.0, 0.0, -120.0]);
+    }
+
+    #[test]
+    fn test_serializes_as_a_base64_string() {
+        let json = serde_json::to_string(&Frame {
+            bins: vec![-1.0, 0.0],
+        })
+        .unwrap();
+        assert!(json.contains('"'), "bins should be a string: {json}");
+        assert!(!json.contains('['), "bins should not be an array: {json}");
+    }
+
+    #[test]
+    fn test_clamps_out_of_range_and_non_finite() {
+        let frame = Frame {
+            bins: vec![-400.0, 400.0, f32::NAN, f32::NEG_INFINITY],
+        };
+        let json = serde_json::to_string(&frame).unwrap();
+        let back: Frame = serde_json::from_str(&json).unwrap();
+        assert_eq!(back.bins, vec![-128.0, 127.0, -128.0, -128.0]);
+    }
+
+    #[test]
+    fn test_reads_the_old_array_form() {
+        let back: Frame = serde_json::from_str(r#"{"bins":[-73.25,-20.5]}"#).unwrap();
+        assert_eq!(back.bins, vec![-73.25, -20.5]);
+    }
+
+    /// The point of the change: an ordinary frame gets much smaller.
+    #[test]
+    fn test_frame_is_far_smaller_than_the_array_form() {
+        let bins: Vec<f32> = (0..1024).map(|i| -60.0 - (i % 40) as f32 * 0.37).collect();
+        let compact = serde_json::to_string(&Frame { bins: bins.clone() }).unwrap();
+        let verbose = serde_json::to_string(&bins).unwrap();
+        assert!(
+            compact.len() * 5 < verbose.len(),
+            "compact {} bytes vs array {} bytes",
+            compact.len(),
+            verbose.len()
+        );
+    }
+}
@@ -394,6 +394,12 @@ fn default_wfm_denoise_level() -> WfmDenoiseLevel {
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 pub struct SpectrumData {
    /// FFT magnitude bins in dBFS, FFT-shifted so DC (centre frequency) is at index N/2.
+    ///
+    /// On the wire these are base64-encoded `i8` whole dBFS (see
+    /// `spectrum_wire`), which is what the display draws anyway; the TypeScript
+    /// type describes the decoded array the browser receives over SSE.
+    #[serde(with = "crate::rig::spectrum_wire")]
+    #[ts(type = "Array<number>")]
    pub bins: Vec<f32>,
    /// Centre frequency of the SDR capture in Hz.
    #[ts(type = "number")]
@@ -18,4 +18,6 @@ pub use auth::{NoAuthValidator, SimpleTokenValidator, TokenValidator};
 pub use codec::{mode_to_string, parse_envelope, parse_mode};
 pub use decoders::{DecoderActivation, DecoderDescriptor, DECODER_REGISTRY};
 pub use mapping::{client_command_to_rig, rig_command_to_client};
-pub use types::{ClientCommand, ClientEnvelope, ClientResponse, MeterUpdate, RigEntry};
+pub use types::{
+    ClientCommand, ClientEnvelope, ClientResponse, MeterUpdate, RigEntry, SpectrumFrame,
+};
@@ -102,7 +102,7 @@ macro_rules! define_command_mapping {

 define_command_mapping! {
    // ── Client-only variants (no RigCommand counterpart) ─────────────
-    client_only: GetRigs, GetSatPasses, SubscribeMeter;
+    client_only: GetRigs, GetSatPasses, SubscribeMeter, SubscribeSpectrum;

    // ── Unit variants (no payload) ───────────────────────────────────
    unit:
@@ -130,6 +130,28 @@ pub enum ClientCommand {
    /// newline-delimited `MeterUpdate` JSON frames and no further commands or
    /// regular responses are sent.  Intended for a dedicated TCP connection.
    SubscribeMeter,
+    /// Subscribe to a per-rig spectrum stream on this connection.  Like
+    /// `SubscribeMeter`, the connection becomes a one-way flow of
+    /// newline-delimited `SpectrumFrame` JSON and no further commands or
+    /// regular responses are sent.
+    ///
+    /// Polling `GetSpectrum` costs a round trip per frame, which caps the frame
+    /// rate at 1/RTT no matter how often the client asks; the server pushes at
+    /// its own cadence instead.  Clients fall back to polling when the server
+    /// rejects this command.
+    SubscribeSpectrum,
+}
+
+/// One spectrum frame pushed by the server on a dedicated spectrum stream.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub struct SpectrumFrame {
+    /// Rig identifier this frame belongs to.
+    pub rig_id: String,
+    /// The frame itself; bins travel base64-encoded (see `spectrum_wire`).
+    pub spectrum: trx_core::rig::state::SpectrumData,
+    /// Virtual-channel RDS state, mirroring what `GetSpectrum` returned.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub vchan_rds: Option<Vec<trx_core::rig::state::VchanRdsEntry>>,
 }

 /// Fast meter sample pushed by the server on a dedicated meter stream.
@@ -32,6 +32,7 @@ cpal = "0.15"
 num-complex = "0.4"
 opus = "0.3"
 trx-app = { path = "../trx-app" }
+trx-config = { path = "../trx-config" }
 trx-backend = { path = "trx-backend", features = ["soapysdr"] }
 trx-ais = { path = "../decoders/trx-ais" }
 trx-vdes = { path = "../decoders/trx-vdes" }
@@ -2291,15 +2291,12 @@ pub async fn run_wefax_decoder(
    mut state_rx: watch::Receiver<RigState>,
    decode_tx: broadcast::Sender<DecodedMessage>,
    histories: Arc<DecoderHistories>,
+    wefax_output_dir: std::path::PathBuf,
 ) {
    use trx_wefax::{WefaxConfig, WefaxDecoder, WefaxEvent};

    info!("WEFAX decoder started ({}Hz, {} ch)", sample_rate, channels);

-    let wefax_output_dir = dirs::cache_dir()
-        .unwrap_or_else(|| std::path::PathBuf::from(".cache"))
-        .join("trx-rs")
-        .join("wefax");
    let config = WefaxConfig {
        output_dir: Some(wefax_output_dir.to_string_lossy().into_owned()),
        ..WefaxConfig::default()
@@ -494,6 +494,58 @@ where
            }
        };

+        // SubscribeSpectrum: turns this connection into a one-way spectrum
+        // stream.  Polling GetSpectrum costs a round trip per frame, so a
+        // client on a slow link could never reach the frame rate it asked for;
+        // pushing decouples the rate from the latency.
+        if matches!(envelope.cmd, ClientCommand::SubscribeSpectrum) {
+            let mut spectrum_rx = handle.spectrum_tx.subscribe();
+            let io_timeout = timeouts.io_timeout;
+            info!(
+                "Client {} subscribed to spectrum stream for rig '{}'",
+                addr, target_rig_id
+            );
+            loop {
+                tokio::select! {
+                    frame = spectrum_rx.recv() => {
+                        match frame {
+                            Ok(frame) => {
+                                let Ok(mut line) = serde_json::to_string(&frame) else { continue };
+                                line.push('\n');
+                                let write = time::timeout(
+                                    io_timeout,
+                                    writer.write_all(line.as_bytes()),
+                                ).await;
+                                match write {
+                                    Ok(Ok(())) => {}
+                                    Ok(Err(e)) => {
+                                        info!("Client {} spectrum write failed: {}", addr, e);
+                                        break;
+                                    }
+                                    Err(_) => {
+                                        info!("Client {} spectrum write timed out", addr);
+                                        break;
+                                    }
+                                }
+                            }
+                            // A client that cannot keep up skips to the newest
+                            // frame; stale spectrum is not worth drawing.
+                            Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => continue,
+                            Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
+                        }
+                    }
+                    changed = shutdown_rx.changed() => {
+                        match changed {
+                            Ok(()) if *shutdown_rx.borrow() => break,
+                            Ok(()) => {}
+                            Err(_) => break,
+                        }
+                    }
+                }
+            }
+            break;
+        }
+
        // SubscribeMeter: turns this connection into a one-way meter stream.
        // No regular responses are produced; the connection lives until the
        // client disconnects or shutdown fires.
@@ -732,6 +784,7 @@ mod tests {
        let (state_tx, state_rx) = watch::channel(state);
        let _state_tx = state_tx;
        let (meter_tx, _) = tokio::sync::broadcast::channel(8);
+        let (spectrum_tx, _) = tokio::sync::broadcast::channel(4);
        let handle = RigHandle {
            rig_id: "default".to_string(),
            display_name: "Default Rig".to_string(),
@@ -739,6 +792,7 @@ mod tests {
            state_rx,
            audio_port: 4531,
            meter_tx,
+            spectrum_tx,
        };
        let mut map = HashMap::new();
        map.insert("default".to_string(), handle);
@@ -933,6 +987,7 @@ mod tests {
            state_rx: state_rx_a,
            audio_port: 4531,
            meter_tx: meter_tx_a,
+            spectrum_tx: tokio::sync::broadcast::channel(4).0,
        };

        let (tx_b, rx_b) = mpsc::channel::<RigRequest>(8);
@@ -945,6 +1000,7 @@ mod tests {
            state_rx: state_rx_b,
            audio_port: 4532,
            meter_tx: meter_tx_b,
+            spectrum_tx: tokio::sync::broadcast::channel(4).0,
        };

        let mut map = HashMap::new();
@@ -953,6 +1009,67 @@ mod tests {
        (Arc::new(map), "rig_hf".to_string(), rx_a, rx_b)
    }

+    /// Polling spectrum costs a round trip per frame, so the rate a client can
+    /// reach is capped by latency rather than by what it asked for.  Subscribed
+    /// clients get frames pushed instead; this is that path end to end.
+    #[tokio::test]
+    async fn subscribe_spectrum_pushes_frames() {
+        use trx_core::rig::state::SpectrumData;
+
+        let (rigs, default_id) = make_rigs(sample_state());
+        let spectrum_tx = rigs.get("default").expect("rig").spectrum_tx.clone();
+        let ctx = make_ctx(rigs, default_id, HashSet::new());
+        let (mut reader, mut writer, handle, shutdown_tx) = spawn_client_io(ctx);
+
+        writer
+            .write_all(br#"{"cmd":"subscribe_spectrum"}"#)
+            .await
+            .expect("write");
+        writer.write_all(b"\n").await.expect("newline");
+        writer.flush().await.expect("flush");
+
+        // The subscription is registered asynchronously; publish until it takes.
+        let frame = trx_protocol::SpectrumFrame {
+            rig_id: "default".to_string(),
+            spectrum: SpectrumData {
+                bins: vec![-73.4, -20.6, 0.0],
+                center_hz: 14_200_000,
+                sample_rate: 1_920_000,
+                rds: None,
+            },
+            vchan_rds: None,
+        };
+        let mut line = String::new();
+        for _ in 0..50 {
+            let _ = spectrum_tx.send(frame.clone());
+            tokio::select! {
+                read = reader.read_line(&mut line) => {
+                    if read.expect("read") > 0 && !line.trim().is_empty() {
+                        break;
+                    }
+                    line.clear();
+                }
+                _ = tokio::time::sleep(Duration::from_millis(20)) => {}
+            }
+        }
+
+        let received: trx_protocol::SpectrumFrame =
+            serde_json::from_str(line.trim()).unwrap_or_else(|e| panic!("frame {line:?}: {e}"));
+        assert_eq!(received.rig_id, "default");
+        assert_eq!(received.spectrum.center_hz, 14_200_000);
+        // Bins survive the trip quantized to whole dBFS, which is the
+        // resolution the display draws at anyway.
+        assert_eq!(received.spectrum.bins, vec![-73.0, -21.0, 0.0]);
+        // And they travel as base64 rather than a JSON array of floats.
+        assert!(
+            !line.contains("-73"),
+            "bins should not be spelled out on the wire: {line}"
+        );
+
+        let _ = shutdown_tx.send(true);
+        let _ = handle.await;
+    }
+
    #[tokio::test]
    async fn multi_rig_state_isolation() {
        let state_hf = sample_state_custom("HF-Dummy", 14_200_000, trx_core::RigMode::USB);
@@ -30,6 +30,8 @@ use trx_core::audio::AudioStreamInfo;

 use trx_app::{init_logging, normalize_name};
 use trx_backend::{register_builtin_backends_on, RegistrationContext, RigAccess};
+use trx_config::shared::BoundSocket;
+use trx_config::ConfigFile;
 use trx_core::rig::controller::{AdaptivePolling, ExponentialBackoff};
 use trx_core::rig::request::RigRequest;
 use trx_core::rig::state::RigState;
@@ -56,6 +58,12 @@ struct Cli {
    /// Print example configuration and exit
    #[arg(long = "print-config")]
    print_config: bool,
+    /// Treat unknown configuration keys as a fatal error
+    #[arg(long = "strict-config")]
+    strict_config: bool,
+    /// Validate the configuration and exit without starting anything
+    #[arg(long = "check-config")]
+    check_config: bool,
    /// Rig backend to use (e.g. ft817, ft450d)
    #[arg(short = 'r', long = "rig")]
    rig: Option<String>,
@@ -352,6 +360,7 @@ fn build_sdr_rig_from_instance(rig_cfg: &RigInstanceConfig) -> SdrRigBuildResult
        max_virtual_channels: rig_cfg.sdr.max_virtual_channels,
        nb_enabled: rig_cfg.sdr.noise_blanker.enabled,
        nb_threshold: rig_cfg.sdr.noise_blanker.threshold,
+        spectrum_fft_size: rig_cfg.sdr.spectrum_fft_size,
    })?;

    let pcm_rx = sdr_rig.subscribe_pcm();
@@ -452,6 +461,7 @@ fn build_rig_task_config(
        prebuilt_rig: None,
        command_exec_timeout: Duration::from_millis(timeouts.command_exec_timeout_ms),
        poll_refresh_timeout: Duration::from_millis(timeouts.poll_refresh_timeout_ms),
+        spectrum_interval_ms: rig_cfg.sdr.spectrum_interval_ms,
    }
 }

@@ -653,38 +663,44 @@ fn spawn_rig_audio_stack(
        }

        // Spawn APRS decoder task
-        let aprs_pcm_rx = pcm_tx.subscribe();
-        let aprs_state_rx = state_rx.clone();
-        let aprs_decode_tx = decode_tx.clone();
-        let aprs_sr = rig_cfg.audio.sample_rate;
-        let aprs_ch = rig_cfg.audio.channels;
-        let aprs_shutdown_rx = shutdown_rx.clone();
-        let aprs_logs = decoder_logs.clone();
-        let aprs_histories = histories.clone();
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_aprs_decoder(aprs_sr, aprs_ch as u16, aprs_pcm_rx, aprs_state_rx, aprs_decode_tx, aprs_logs, aprs_histories) => {}
-                _ = wait_for_shutdown(aprs_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("aprs") {
+            let aprs_pcm_rx = pcm_tx.subscribe();
+            let aprs_state_rx = state_rx.clone();
+            let aprs_decode_tx = decode_tx.clone();
+            let aprs_sr = rig_cfg.audio.sample_rate;
+            let aprs_ch = rig_cfg.audio.channels;
+            let aprs_shutdown_rx = shutdown_rx.clone();
+            let aprs_logs = decoder_logs.clone();
+            let aprs_histories = histories.clone();
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_aprs_decoder(aprs_sr, aprs_ch as u16, aprs_pcm_rx, aprs_state_rx, aprs_decode_tx, aprs_logs, aprs_histories) => {}
+                    _ = wait_for_shutdown(aprs_shutdown_rx) => {}
+                }
+            }));
+        }

        // Spawn HF APRS decoder task
-        let hf_aprs_pcm_rx = pcm_tx.subscribe();
-        let hf_aprs_state_rx = state_rx.clone();
-        let hf_aprs_decode_tx = decode_tx.clone();
-        let hf_aprs_sr = rig_cfg.audio.sample_rate;
-        let hf_aprs_ch = rig_cfg.audio.channels;
-        let hf_aprs_shutdown_rx = shutdown_rx.clone();
-        let hf_aprs_logs = decoder_logs.clone();
-        let hf_aprs_histories = histories.clone();
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_hf_aprs_decoder(hf_aprs_sr, hf_aprs_ch as u16, hf_aprs_pcm_rx, hf_aprs_state_rx, hf_aprs_decode_tx, hf_aprs_logs, hf_aprs_histories) => {}
-                _ = wait_for_shutdown(hf_aprs_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("aprs_hf") {
+            let hf_aprs_pcm_rx = pcm_tx.subscribe();
+            let hf_aprs_state_rx = state_rx.clone();
+            let hf_aprs_decode_tx = decode_tx.clone();
+            let hf_aprs_sr = rig_cfg.audio.sample_rate;
+            let hf_aprs_ch = rig_cfg.audio.channels;
+            let hf_aprs_shutdown_rx = shutdown_rx.clone();
+            let hf_aprs_logs = decoder_logs.clone();
+            let hf_aprs_histories = histories.clone();
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_hf_aprs_decoder(hf_aprs_sr, hf_aprs_ch as u16, hf_aprs_pcm_rx, hf_aprs_state_rx, hf_aprs_decode_tx, hf_aprs_logs, hf_aprs_histories) => {}
+                    _ = wait_for_shutdown(hf_aprs_shutdown_rx) => {}
+                }
+            }));
+        }

-        if let Some((ais_a_pcm_rx, ais_b_pcm_rx)) = sdr_ais_pcm_rx {
+        if let Some((ais_a_pcm_rx, ais_b_pcm_rx)) =
+            sdr_ais_pcm_rx.filter(|_| rig_cfg.decoders.is_enabled("ais"))
+        {
            let ais_state_rx = state_rx.clone();
            let ais_decode_tx = decode_tx.clone();
            let ais_shutdown_rx = shutdown_rx.clone();
@@ -699,7 +715,7 @@ fn spawn_rig_audio_stack(
            }));
        }

-        if let Some(vdes_iq_rx) = sdr_vdes_iq_rx {
+        if let Some(vdes_iq_rx) = sdr_vdes_iq_rx.filter(|_| rig_cfg.decoders.is_enabled("vdes")) {
            let vdes_state_rx = state_rx.clone();
            let vdes_decode_tx = decode_tx.clone();
            let vdes_shutdown_rx = shutdown_rx.clone();
@@ -721,55 +737,61 @@ fn spawn_rig_audio_stack(
        }

        // Spawn CW decoder task
-        let cw_pcm_rx = pcm_tx.subscribe();
-        let cw_state_rx = state_rx.clone();
-        let cw_decode_tx = decode_tx.clone();
-        let cw_sr = rig_cfg.audio.sample_rate;
-        let cw_ch = rig_cfg.audio.channels;
-        let cw_shutdown_rx = shutdown_rx.clone();
-        let cw_logs = decoder_logs.clone();
-        let cw_histories = histories.clone();
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_cw_decoder(cw_sr, cw_ch as u16, cw_pcm_rx, cw_state_rx, cw_decode_tx, cw_logs, cw_histories) => {}
-                _ = wait_for_shutdown(cw_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("cw") {
+            let cw_pcm_rx = pcm_tx.subscribe();
+            let cw_state_rx = state_rx.clone();
+            let cw_decode_tx = decode_tx.clone();
+            let cw_sr = rig_cfg.audio.sample_rate;
+            let cw_ch = rig_cfg.audio.channels;
+            let cw_shutdown_rx = shutdown_rx.clone();
+            let cw_logs = decoder_logs.clone();
+            let cw_histories = histories.clone();
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_cw_decoder(cw_sr, cw_ch as u16, cw_pcm_rx, cw_state_rx, cw_decode_tx, cw_logs, cw_histories) => {}
+                    _ = wait_for_shutdown(cw_shutdown_rx) => {}
+                }
+            }));
+        }

        // Spawn FT8 decoder task
-        let ft8_pcm_rx = pcm_tx.subscribe();
-        let ft8_state_rx = state_rx.clone();
-        let ft8_decode_tx = decode_tx.clone();
-        let ft8_sr = rig_cfg.audio.sample_rate;
-        let ft8_ch = rig_cfg.audio.channels;
-        let ft8_shutdown_rx = shutdown_rx.clone();
-        let ft8_logs = decoder_logs.clone();
-        let ft8_histories = histories.clone();
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_ft8_decoder(ft8_sr, ft8_ch as u16, ft8_pcm_rx, ft8_state_rx, ft8_decode_tx, ft8_logs, ft8_histories) => {}
-                _ = wait_for_shutdown(ft8_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("ft8") {
+            let ft8_pcm_rx = pcm_tx.subscribe();
+            let ft8_state_rx = state_rx.clone();
+            let ft8_decode_tx = decode_tx.clone();
+            let ft8_sr = rig_cfg.audio.sample_rate;
+            let ft8_ch = rig_cfg.audio.channels;
+            let ft8_shutdown_rx = shutdown_rx.clone();
+            let ft8_logs = decoder_logs.clone();
+            let ft8_histories = histories.clone();
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_ft8_decoder(ft8_sr, ft8_ch as u16, ft8_pcm_rx, ft8_state_rx, ft8_decode_tx, ft8_logs, ft8_histories) => {}
+                    _ = wait_for_shutdown(ft8_shutdown_rx) => {}
+                }
+            }));
+        }

        // Spawn FT4 decoder task
-        let ft4_pcm_rx = pcm_tx.subscribe();
-        let ft4_state_rx = state_rx.clone();
-        let ft4_decode_tx = decode_tx.clone();
-        let ft4_sr = rig_cfg.audio.sample_rate;
-        let ft4_ch = rig_cfg.audio.channels;
-        let ft4_shutdown_rx = shutdown_rx.clone();
-        let ft4_histories = histories.clone();
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_ft4_decoder(ft4_sr, ft4_ch as u16, ft4_pcm_rx, ft4_state_rx, ft4_decode_tx, ft4_histories) => {}
-                _ = wait_for_shutdown(ft4_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("ft4") {
+            let ft4_pcm_rx = pcm_tx.subscribe();
+            let ft4_state_rx = state_rx.clone();
+            let ft4_decode_tx = decode_tx.clone();
+            let ft4_sr = rig_cfg.audio.sample_rate;
+            let ft4_ch = rig_cfg.audio.channels;
+            let ft4_shutdown_rx = shutdown_rx.clone();
+            let ft4_histories = histories.clone();
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_ft4_decoder(ft4_sr, ft4_ch as u16, ft4_pcm_rx, ft4_state_rx, ft4_decode_tx, ft4_histories) => {}
+                    _ = wait_for_shutdown(ft4_shutdown_rx) => {}
+                }
+            }));
+        }

        // Spawn FT2 decoder task
        #[cfg(feature = "ft2")]
-        {
+        if rig_cfg.decoders.is_enabled("ft2") {
            let ft2_pcm_rx = pcm_tx.subscribe();
            let ft2_state_rx = state_rx.clone();
            let ft2_decode_tx = decode_tx.clone();
@@ -786,73 +808,76 @@ fn spawn_rig_audio_stack(
        }

        // Spawn WSPR decoder task
-        let wspr_pcm_rx = pcm_tx.subscribe();
-        let wspr_state_rx = state_rx.clone();
-        let wspr_decode_tx = decode_tx.clone();
-        let wspr_sr = rig_cfg.audio.sample_rate;
-        let wspr_ch = rig_cfg.audio.channels;
-        let wspr_shutdown_rx = shutdown_rx.clone();
-        let wspr_logs = decoder_logs.clone();
-        let wspr_histories = histories.clone();
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_wspr_decoder(wspr_sr, wspr_ch as u16, wspr_pcm_rx, wspr_state_rx, wspr_decode_tx, wspr_logs, wspr_histories) => {}
-                _ = wait_for_shutdown(wspr_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("wspr") {
+            let wspr_pcm_rx = pcm_tx.subscribe();
+            let wspr_state_rx = state_rx.clone();
+            let wspr_decode_tx = decode_tx.clone();
+            let wspr_sr = rig_cfg.audio.sample_rate;
+            let wspr_ch = rig_cfg.audio.channels;
+            let wspr_shutdown_rx = shutdown_rx.clone();
+            let wspr_logs = decoder_logs.clone();
+            let wspr_histories = histories.clone();
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_wspr_decoder(wspr_sr, wspr_ch as u16, wspr_pcm_rx, wspr_state_rx, wspr_decode_tx, wspr_logs, wspr_histories) => {}
+                    _ = wait_for_shutdown(wspr_shutdown_rx) => {}
+                }
+            }));
+        }

        // Spawn Meteor-M LRPT decoder task
-        let lrpt_pcm_rx = pcm_tx.subscribe();
-        let lrpt_state_rx = state_rx.clone();
-        let lrpt_decode_tx = decode_tx.clone();
-        let lrpt_sr = rig_cfg.audio.sample_rate;
-        let lrpt_ch = rig_cfg.audio.channels;
-        let lrpt_shutdown_rx = shutdown_rx.clone();
-        let lrpt_histories = histories.clone();
-        let lrpt_output_dir = dirs::cache_dir()
-            .unwrap_or_else(|| std::path::PathBuf::from(".cache"))
-            .join("trx-rs")
-            .join("lrpt");
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_lrpt_decoder(lrpt_sr, lrpt_ch as u16, lrpt_pcm_rx, lrpt_state_rx, lrpt_decode_tx, lrpt_histories, lrpt_output_dir) => {}
-                _ = wait_for_shutdown(lrpt_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("lrpt") {
+            let lrpt_pcm_rx = pcm_tx.subscribe();
+            let lrpt_state_rx = state_rx.clone();
+            let lrpt_decode_tx = decode_tx.clone();
+            let lrpt_sr = rig_cfg.audio.sample_rate;
+            let lrpt_ch = rig_cfg.audio.channels;
+            let lrpt_shutdown_rx = shutdown_rx.clone();
+            let lrpt_histories = histories.clone();
+            let lrpt_output_dir = rig_cfg.decoders.output_dir_for("lrpt");
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_lrpt_decoder(lrpt_sr, lrpt_ch as u16, lrpt_pcm_rx, lrpt_state_rx, lrpt_decode_tx, lrpt_histories, lrpt_output_dir) => {}
+                    _ = wait_for_shutdown(lrpt_shutdown_rx) => {}
+                }
+            }));
+        }

        // Spawn WEFAX decoder task
-        let wefax_pcm_rx = pcm_tx.subscribe();
-        let wefax_state_rx = state_rx.clone();
-        let wefax_decode_tx = decode_tx.clone();
-        let wefax_sr = rig_cfg.audio.sample_rate;
-        let wefax_ch = rig_cfg.audio.channels;
-        let wefax_shutdown_rx = shutdown_rx.clone();
-        let wefax_histories = histories.clone();
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_wefax_decoder(wefax_sr, wefax_ch as u16, wefax_pcm_rx, wefax_state_rx, wefax_decode_tx, wefax_histories) => {}
-                _ = wait_for_shutdown(wefax_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("wefax") {
+            let wefax_pcm_rx = pcm_tx.subscribe();
+            let wefax_state_rx = state_rx.clone();
+            let wefax_decode_tx = decode_tx.clone();
+            let wefax_sr = rig_cfg.audio.sample_rate;
+            let wefax_ch = rig_cfg.audio.channels;
+            let wefax_shutdown_rx = shutdown_rx.clone();
+            let wefax_histories = histories.clone();
+            let wefax_output_dir = rig_cfg.decoders.output_dir_for("wefax");
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_wefax_decoder(wefax_sr, wefax_ch as u16, wefax_pcm_rx, wefax_state_rx, wefax_decode_tx, wefax_histories, wefax_output_dir) => {}
+                    _ = wait_for_shutdown(wefax_shutdown_rx) => {}
+                }
+            }));
+        }

        // Spawn SSTV decoder task
-        let sstv_pcm_rx = pcm_tx.subscribe();
-        let sstv_state_rx = state_rx.clone();
-        let sstv_decode_tx = decode_tx.clone();
-        let sstv_sr = rig_cfg.audio.sample_rate;
-        let sstv_ch = rig_cfg.audio.channels;
-        let sstv_shutdown_rx = shutdown_rx.clone();
-        let sstv_histories = histories.clone();
-        let sstv_output_dir = dirs::cache_dir()
-            .unwrap_or_else(|| std::path::PathBuf::from(".cache"))
-            .join("trx-rs")
-            .join("sstv");
-        handles.push(tokio::spawn(async move {
-            tokio::select! {
-                _ = audio::run_sstv_decoder(sstv_sr, sstv_ch as u16, sstv_pcm_rx, sstv_state_rx, sstv_decode_tx, sstv_histories, sstv_output_dir) => {}
-                _ = wait_for_shutdown(sstv_shutdown_rx) => {}
-            }
-        }));
+        if rig_cfg.decoders.is_enabled("sstv") {
+            let sstv_pcm_rx = pcm_tx.subscribe();
+            let sstv_state_rx = state_rx.clone();
+            let sstv_decode_tx = decode_tx.clone();
+            let sstv_sr = rig_cfg.audio.sample_rate;
+            let sstv_ch = rig_cfg.audio.channels;
+            let sstv_shutdown_rx = shutdown_rx.clone();
+            let sstv_histories = histories.clone();
+            let sstv_output_dir = rig_cfg.decoders.output_dir_for("sstv");
+            handles.push(tokio::spawn(async move {
+                tokio::select! {
+                    _ = audio::run_sstv_decoder(sstv_sr, sstv_ch as u16, sstv_pcm_rx, sstv_state_rx, sstv_decode_tx, sstv_histories, sstv_output_dir) => {}
+                    _ = wait_for_shutdown(sstv_shutdown_rx) => {}
+                }
+            }));
+        }
    }

    if rig_cfg.audio.tx_enabled {
@@ -882,6 +907,82 @@ fn spawn_rig_audio_stack(
    handles
 }

+/// Sockets this process will bind, given the config and the CLI overrides.
+///
+/// `--listen` overrides the bind address of both the control listener and every
+/// rig's audio listener, so the two callers of this must agree on the rules.
+fn bound_sockets(cli: &Cli, cfg: &ServerConfig, rigs: &[RigInstanceConfig]) -> Vec<BoundSocket> {
+    let mut sockets = Vec::new();
+    if cfg.listen.enabled {
+        sockets.push(BoundSocket::new(
+            cli.listen.unwrap_or(cfg.listen.listen),
+            cli.port.unwrap_or(cfg.listen.port),
+            "[listen]",
+        ));
+    }
+    let audio_ip = cli.listen.unwrap_or(cfg.audio.listen);
+    for rig in rigs {
+        if rig.audio.enabled {
+            sockets.push(BoundSocket::new(
+                audio_ip,
+                rig.audio.port,
+                format!("rig \"{}\" [audio]", rig.id),
+            ));
+        }
+    }
+    sockets
+}
+
+/// `--check-config`: report everything wrong with the configuration and exit.
+///
+/// Unlike startup, this reports every problem it finds rather than stopping at
+/// the first, so a config can be fixed in one pass.
+fn check_config(cli: &Cli, loaded: &trx_config::ConfigLoad<ServerConfig>) -> DynResult<()> {
+    match &loaded.path {
+        Some(path) => println!("{}", path.display()),
+        None => println!("(no config file found; checking built-in defaults)"),
+    }
+
+    let mut warnings: Vec<String> = loaded.unknown_keys.iter().map(|k| k.to_string()).collect();
+    warnings.extend(ServerConfig::deprecations(&loaded.present_keys));
+    for warning in &warnings {
+        println!("  warning: {}", warning);
+    }
+
+    let mut cfg = loaded.config.clone();
+    let mut errors = Vec::new();
+    if let Err(e) = cfg.resolve_secrets(loaded.path.as_deref()) {
+        errors.push(e);
+    }
+    let cfg = &cfg;
+    let rigs = cfg.resolved_rigs();
+
+    errors.extend(cfg.validate_all());
+    errors.extend(cfg.validate_sdr());
+    errors.extend(cfg.validate_resolved_all(&rigs, &bound_sockets(cli, cfg, &rigs)));
+
+    for e in &errors {
+        println!("  error: {}", e);
+    }
+
+    if errors.is_empty() {
+        println!(
+            "  OK: {} rig(s) configured: {}",
+            rigs.len(),
+            rigs.iter()
+                .map(|r| r.id.as_str())
+                .collect::<Vec<_>>()
+                .join(", ")
+        );
+        if !warnings.is_empty() {
+            println!("  {} warning(s)", warnings.len());
+        }
+        Ok(())
+    } else {
+        Err(format!("{} error(s), {} warning(s)", errors.len(), warnings.len()).into())
+    }
+}
+
 #[tokio::main]
 async fn main() -> DynResult<()> {
    let mut bootstrap_ctx = RegistrationContext::new();
@@ -894,12 +995,30 @@ async fn main() -> DynResult<()> {
        return Ok(());
    }

-    let (cfg, config_path) = if let Some(ref path) = cli.config {
-        let cfg = ServerConfig::load_from_file(path)?;
-        (cfg, Some(path.clone()))
+    let loaded = if let Some(ref path) = cli.config {
+        ServerConfig::load_from_file(path)?
    } else {
        ServerConfig::load_from_default_paths()?
    };
+    let config_path = loaded.path.clone();
+
+    if cli.check_config {
+        return check_config(&cli, &loaded);
+    }
+
+    // Logging comes up before any config complaint so the warnings are visible.
+    init_logging(loaded.config.general.log_level.as_deref());
+
+    if let Some(ref path) = config_path {
+        info!("Loaded configuration from {}", path.display());
+    }
+    loaded.report_unknown_keys(cli.strict_config)?;
+    loaded.report_deprecations();
+
+    let mut cfg = loaded.config;
+    // Secrets configured as *_file are read before validation, so everything
+    // downstream sees resolved values.
+    cfg.resolve_secrets(config_path.as_deref())?;
    cfg.validate()
        .map_err(|e| format!("Invalid server configuration: {}", e))?;

@@ -912,12 +1031,6 @@ async fn main() -> DynResult<()> {
        std::process::exit(1);
    }

-    init_logging(cfg.general.log_level.as_deref());
-
-    if let Some(ref path) = config_path {
-        info!("Loaded configuration from {}", path.display());
-    }
-
    let registry = Arc::new(bootstrap_ctx);

    // --- Resolve the effective rig list ---
@@ -979,6 +1092,12 @@ async fn main() -> DynResult<()> {
        (callsign, cfg.general.latitude, cfg.general.longitude)
    };

+    // Second validation phase: now that CLI overrides have been folded in, check
+    // the things that need the final rig list — chiefly that no two listeners
+    // claim the same socket.
+    cfg.validate_resolved(&resolved_rigs, &bound_sockets(&cli, &cfg, &resolved_rigs))
+        .map_err(|e| format!("Invalid server configuration: {}", e))?;
+
    info!(
        "Starting trx-server with {} rig(s): {}",
        resolved_rigs.len(),
@@ -1098,6 +1217,9 @@ async fn main() -> DynResult<()> {
        let (state_tx, state_rx) = watch::channel(initial_state);
        let (meter_tx, _) =
            broadcast::channel::<trx_protocol::MeterUpdate>(rig_handle::METER_BROADCAST_CAPACITY);
+        let (spectrum_tx, _) = broadcast::channel::<trx_protocol::SpectrumFrame>(
+            rig_handle::SPECTRUM_BROADCAST_CAPACITY,
+        );

        let mut task_config = build_rig_task_config(
            rig_cfg,
@@ -1125,12 +1247,14 @@ async fn main() -> DynResult<()> {
        let rig_shutdown_rx = shutdown_rx.clone();
        let rig_id_supervisor = rig_cfg.id.clone();
        let meter_tx_task = meter_tx.clone();
+        let spectrum_tx_task = spectrum_tx.clone();
        task_handles.push(tokio::spawn(async move {
            let result = rig_task::run_rig_task(
                task_config,
                rig_rx,
                state_tx.clone(),
                meter_tx_task,
+                spectrum_tx_task,
                rig_shutdown_rx,
            )
            .await;
@@ -1177,6 +1301,7 @@ async fn main() -> DynResult<()> {
        rig_handles.insert(
            rig_cfg.id.clone(),
            RigHandle {
+                spectrum_tx: spectrum_tx.clone(),
                rig_id: rig_cfg.id.clone(),
                display_name: rig_cfg.display_name().to_string(),
                rig_tx,
@@ -8,13 +8,18 @@ use tokio::sync::{broadcast, mpsc, watch};

 use trx_core::rig::request::RigRequest;
 use trx_core::rig::state::RigState;
-use trx_protocol::MeterUpdate;
+use trx_protocol::{MeterUpdate, SpectrumFrame};

 /// Bounded broadcast capacity for the meter stream.  Keeps ~0.5 s of buffered
 /// samples at 30 Hz — more than enough slack to tolerate a scheduling blip
 /// without forcing the producer to block or drop silently.
 pub const METER_BROADCAST_CAPACITY: usize = 16;

+/// Bounded broadcast capacity for the spectrum stream.  Frames are large and
+/// only the newest one is worth drawing, so the buffer stays shallow: a slow
+/// client lags and skips rather than making the server hold stale frames.
+pub const SPECTRUM_BROADCAST_CAPACITY: usize = 4;
+
 /// A handle to a single running rig backend.
 ///
 /// One `RigHandle` is created per rig in `main.rs` and stored in the shared
@@ -34,4 +39,8 @@ pub struct RigHandle {
    /// ~6–7 Hz (CAT).  Consumed by `SubscribeMeter` clients; independent of
    /// the slower `state_rx` snapshot path.
    pub meter_tx: broadcast::Sender<MeterUpdate>,
+    /// Per-rig spectrum frames published by `rig_task` while at least one
+    /// client is subscribed.  Consumed by `SubscribeSpectrum` clients; the
+    /// producer skips the work entirely when nobody is listening.
+    pub spectrum_tx: broadcast::Sender<SpectrumFrame>,
 }
@@ -23,7 +23,7 @@ use trx_core::rig::request::RigRequest;
 use trx_core::rig::state::{RigMode, RigSnapshot, RigState};
 use trx_core::rig::{RigCat, RigRxStatus, RigTxStatus};
 use trx_core::{DynResult, RigError, RigResult};
-use trx_protocol::MeterUpdate;
+use trx_protocol::{MeterUpdate, SpectrumFrame};

 use crate::audio::DecoderHistories;
 use crate::error::is_invalid_bcd_error;
@@ -64,6 +64,8 @@ pub struct RigTaskConfig {
    pub command_exec_timeout: Duration,
    /// Maximum time for a CAT poll refresh cycle.
    pub poll_refresh_timeout: Duration,
+    /// How often to push a spectrum frame to subscribed clients, in ms.
+    pub spectrum_interval_ms: u64,
 }

 impl Default for RigTaskConfig {
@@ -94,6 +96,7 @@ impl Default for RigTaskConfig {
            prebuilt_rig: None,
            command_exec_timeout: DEFAULT_COMMAND_EXEC_TIMEOUT,
            poll_refresh_timeout: DEFAULT_POLL_REFRESH_TIMEOUT,
+            spectrum_interval_ms: 50,
        }
    }
 }
@@ -115,6 +118,7 @@ pub async fn run_rig_task(
    mut rx: mpsc::Receiver<RigRequest>,
    state_tx: watch::Sender<RigState>,
    meter_tx: broadcast::Sender<MeterUpdate>,
+    spectrum_tx: broadcast::Sender<SpectrumFrame>,
    mut shutdown_rx: watch::Receiver<bool>,
 ) -> DynResult<()> {
    let histories = config.histories.clone();
@@ -273,6 +277,13 @@ pub async fn run_rig_task(
    } else {
        Duration::from_millis(150)
    };
+    // Spectrum frames get their own tick so a subscribed client never pays a
+    // round trip per frame.  The FFT is computed by the SDR thread either way;
+    // this only reads the latest result, and only while somebody is subscribed.
+    let spectrum_tick_duration = Duration::from_millis(config.spectrum_interval_ms.max(1));
+    let mut spectrum_tick: std::pin::Pin<Box<tokio::time::Sleep>> =
+        Box::pin(tokio::time::sleep(spectrum_tick_duration));
+
    let meter_task_start = Instant::now();
    let meter_state_delta_db: f64 = 0.25;
    let rig_id = config.rig_id.clone();
@@ -302,6 +313,21 @@ pub async fn run_rig_task(
                    Err(_) => break,
                }
            }
+            // Push the latest spectrum frame to subscribed clients.
+            _ = &mut spectrum_tick => {
+                spectrum_tick = Box::pin(tokio::time::sleep(spectrum_tick_duration));
+                // `send` fails only when nobody is listening, but building the
+                // frame clones a few KB of bins, so check before doing the work.
+                if spectrum_tx.receiver_count() > 0 {
+                    if let Some(spectrum) = rig.as_sdr_ref().and_then(|s| s.get_spectrum()) {
+                        let _ = spectrum_tx.send(SpectrumFrame {
+                            rig_id: rig_id.clone(),
+                            spectrum,
+                            vchan_rds: rig.as_sdr_ref().and_then(|s| s.get_vchan_rds()),
+                        });
+                    }
+                }
+            }
            // Fast meter-only refresh between full polls.
            _ = &mut meter_tick => {
                meter_tick = Box::pin(tokio::time::sleep(meter_tick_duration));
@@ -154,6 +154,7 @@ impl SdrPipeline {
        squelch_cfg: VirtualSquelchConfig,
        nb_cfg: NoiseBlankerConfig,
        channels: &[(f64, RigMode, u32)],
+        spectrum_fft_size: usize,
    ) -> Self {
        const IQ_BROADCAST_CAPACITY: usize = 64;
        let (iq_tx, _iq_rx) = broadcast::channel::<Vec<Complex<f32>>>(IQ_BROADCAST_CAPACITY);
@@ -219,6 +220,7 @@ impl SdrPipeline {
            .name("sdr-iq-read".to_string())
            .spawn(move || {
                iq_read_loop(
+                    spectrum_fft_size,
                    source,
                    sdr_sample_rate,
                    thread_dsps,
@@ -317,6 +319,7 @@ pub const IQ_BLOCK_SIZE: usize = 4096;

 #[allow(clippy::too_many_arguments)]
 fn iq_read_loop(
+    spectrum_fft_size: usize,
    mut source: Box<dyn IqSource>,
    sdr_sample_rate: u32,
    channel_dsps: Arc<RwLock<Vec<Arc<Mutex<ChannelDsp>>>>>,
@@ -335,7 +338,7 @@ fn iq_read_loop(
    };
    let throttle = !source.is_blocking();

-    let mut spectrum = SpectrumSnapshotter::new();
+    let mut spectrum = SpectrumSnapshotter::new(spectrum_fft_size);
    let mut read_error_streak: u32 = 0;
    let mut zero_read_streak: u32 = 0;
    let mut overflow_log_window_start: Option<Instant> = None;
@@ -572,6 +575,7 @@ mod tests {
            VirtualSquelchConfig::default(),
            NoiseBlankerConfig::default(),
            &[(200_000.0, RigMode::USB, 3000)],
+            1024,
        );
        assert_eq!(pipeline.pcm_senders.len(), 1);
        assert_eq!(pipeline.channel_dsps.read().unwrap().len(), 1);
@@ -590,6 +594,7 @@ mod tests {
            VirtualSquelchConfig::default(),
            NoiseBlankerConfig::default(),
            &[],
+            1024,
        );
        assert_eq!(pipeline.pcm_senders.len(), 0);
        assert_eq!(pipeline.channel_dsps.read().unwrap().len(), 0);
@@ -9,28 +9,36 @@ use num_complex::Complex;
 use rustfft::num_complex::Complex as FftComplex;
 use rustfft::FftPlanner;

-/// Number of FFT bins for the spectrum display.
-pub(super) const SPECTRUM_FFT_SIZE: usize = 1024;
+/// Default number of FFT bins for the spectrum display, used when the config
+/// does not say otherwise.
+pub(super) const DEFAULT_SPECTRUM_FFT_SIZE: usize = 1024;

 /// Update the spectrum buffer every this many IQ blocks (~10 Hz at 1.92 MHz / 4096 block).
 pub(super) const SPECTRUM_UPDATE_BLOCKS: usize = 4;

 pub(super) struct SpectrumSnapshotter {
+    fft_size: usize,
    hann_window: Vec<f32>,
    fft: std::sync::Arc<dyn rustfft::Fft<f32>>,
    counter: usize,
 }

 impl SpectrumSnapshotter {
-    pub(super) fn new() -> Self {
-        let hann_window: Vec<f32> = (0..SPECTRUM_FFT_SIZE)
-            .map(|i| 0.5 * (1.0 - (2.0 * PI * i as f32 / (SPECTRUM_FFT_SIZE - 1) as f32).cos()))
+    pub(super) fn new(fft_size: usize) -> Self {
+        let fft_size = if fft_size >= 2 {
+            fft_size
+        } else {
+            DEFAULT_SPECTRUM_FFT_SIZE
+        };
+        let hann_window: Vec<f32> = (0..fft_size)
+            .map(|i| 0.5 * (1.0 - (2.0 * PI * i as f32 / (fft_size - 1) as f32).cos()))
            .collect();

        let mut planner = FftPlanner::<f32>::new();
-        let fft = planner.plan_fft_forward(SPECTRUM_FFT_SIZE);
+        let fft = planner.plan_fft_forward(fft_size);

        Self {
+            fft_size,
            hann_window,
            fft,
            counter: 0,
@@ -48,7 +56,7 @@ impl SpectrumSnapshotter {
        }
        self.counter = 0;

-        let take = samples.len().min(SPECTRUM_FFT_SIZE);
+        let take = samples.len().min(self.fft_size);
        let mut buf: Vec<FftComplex<f32>> = samples[..take]
            .iter()
            .enumerate()
@@ -59,16 +67,15 @@ impl SpectrumSnapshotter {
                )
            })
            .collect();
-        buf.resize(SPECTRUM_FFT_SIZE, FftComplex::new(0.0, 0.0));
+        buf.resize(self.fft_size, FftComplex::new(0.0, 0.0));
        self.fft.process(&mut buf);

-        let half = SPECTRUM_FFT_SIZE / 2;
+        let half = self.fft_size / 2;
        let bins: Vec<f32> = buf[half..]
            .iter()
            .chain(buf[..half].iter())
            .map(|value| {
-                let mag =
-                    (value.re * value.re + value.im * value.im).sqrt() / SPECTRUM_FFT_SIZE as f32;
+                let mag = (value.re * value.re + value.im * value.im).sqrt() / self.fft_size as f32;
                20.0 * mag.max(1e-10_f32).log10()
            })
            .collect();
@@ -73,6 +73,11 @@ pub struct SoapySdrConfig {
    pub nb_enabled: bool,
    /// Noise blanker impulse threshold multiplier.
    pub nb_threshold: f64,
+    /// FFT bin count for the spectrum display; a power of two.
+    ///
+    /// Fewer bins cost less DSP and put fewer bytes on the network per frame,
+    /// which is what a slow server↔client link cares about.
+    pub spectrum_fft_size: usize,
 }

 impl Default for SoapySdrConfig {
@@ -99,6 +104,7 @@ impl Default for SoapySdrConfig {
            max_virtual_channels: 4,
            nb_enabled: false,
            nb_threshold: 10.0,
+            spectrum_fft_size: 1024,
        }
    }
 }
@@ -194,6 +200,7 @@ impl SoapySdrRig {
        let max_virtual_channels = config.max_virtual_channels;
        let nb_enabled = config.nb_enabled;
        let nb_threshold = config.nb_threshold;
+        let spectrum_fft_size = config.spectrum_fft_size;
        tracing::info!(
            "initialising SoapySDR backend (args={:?}, gain_mode={:?}, gain_db={}, max_gain_db={:?})",
            args,
@@ -293,6 +300,7 @@ impl SoapySdrRig {
                threshold: nb_threshold as f32,
            },
            &all_channels,
+            spectrum_fft_size,
        ));

        let info = RigInfo {
@@ -418,6 +426,7 @@ impl SoapySdrRig {
        nb_threshold: f64,
    ) -> DynResult<Self> {
        Self::new_from_config(SoapySdrConfig {
+            spectrum_fft_size: 1024,
            args: args.to_string(),
            channels: channels.to_vec(),
            gain_mode: gain_mode.to_string(),
@@ -439,6 +439,7 @@ mod tests {
            VirtualSquelchConfig::default(),
            NoiseBlankerConfig::default(),
            &[(0.0, RigMode::USB, 3_000)],
+            1024,
        ))
    }

@@ -1,36 +1,60 @@
+# trx-rs example configuration
+#
+# Generated from the config structs; regenerate with:
+#     cargo run -p trx-config --example generate_example
+#
+# Both sections are optional: trx-server reads [trx-server], trx-client reads
+# [trx-client], and either may live in its own file with the section header
+# omitted.  Any string may use ${ENV_VAR}, and credentials may be moved out of
+# this file with the matching *_file keys.
+#
+# Check a config without starting anything:
+#     trx-server --check-config --config trx-rs.toml
+#     trx-client --check-config --config trx-rs.toml
+
+# Server: drives the radio hardware.
 [trx-server]
 rigs = []

+# Station identity.  Coordinates feed PSKReporter and the map.
 [trx-server.general]
 callsign = "N0CALL"
 log_level = "info"
 latitude = 52.2297
 longitude = 21.0122

+# Single-rig layout.  For several radios, delete this and use [[rigs]].
 [trx-server.rig]
 model = "ft817"
 initial_freq_hz = 144300000
 initial_mode = "USB"

+# How to reach the radio: serial, tcp, or sdr.
 [trx-server.rig.access]
 type = "serial"
 port = "/dev/ttyUSB0"
 baud = 9600

+# CAT polling and retry behaviour.
 [trx-server.behavior]
 poll_interval_ms = 500
 poll_interval_tx_ms = 100
 max_retries = 3
 retry_base_delay_ms = 100
+vfo_prime = true

+# JSON control listener that trx-client connects to.
 [trx-server.listen]
 enabled = true
 listen = "127.0.0.1"
 port = 4530

+# Tokens clients must present.  Empty means no authentication.
+# Use tokens_file = "/etc/trx-rs/tokens" to keep them out of this file.
 [trx-server.listen.auth]
 tokens = []

+# Opus audio stream for trx-client.
 [trx-server.audio]
 enabled = true
 listen = "127.0.0.1"
@@ -42,25 +66,53 @@ channels = 2
 frame_duration_ms = 20
 bitrate_bps = 256000

+# Report FT8/FT4/WSPR spots to pskreporter.info.
 [trx-server.pskreporter]
 enabled = false
 host = "report.pskreporter.info"
 port = 4739

+# Forward received APRS frames to APRS-IS.
 [trx-server.aprsfi]
 enabled = false
 host = "rotate.aprs.net"
 port = 14580
 passcode = -1
+beacon = false
+beacon_interval_secs = 1200
+beacon_symbol_table = "/"
+beacon_symbol_code = "-"

+# Write decodes to JSON Lines files.
 [trx-server.decode_logs]
 enabled = false
-dir = "/path/to/log/dir"
+dir = "/var/lib/trx-rs/decoders"
 aprs_file = "TRXRS-APRS-%YYYY%-%MM%-%DD%.log"
 cw_file = "TRXRS-CW-%YYYY%-%MM%-%DD%.log"
 ft8_file = "TRXRS-FT8-%YYYY%-%MM%-%DD%.log"
 wspr_file = "TRXRS-WSPR-%YYYY%-%MM%-%DD%.log"
+wefax_file = "TRXRS-WEFAX-%YYYY%-%MM%-%DD%.log"

+# Which decoders run.  Trimming this list saves real CPU on small boxes.
+# Valid names: aprs, aprs_hf, ais, cw, ft2, ft4, ft8, lrpt, sstv, vdes, wefax, wspr.
+# output_dir sets where sstv/wefax/lrpt write images (default: user cache dir).
+[trx-server.decoders]
+enabled = [
+    "aprs",
+    "aprs_hf",
+    "ais",
+    "cw",
+    "ft2",
+    "ft4",
+    "ft8",
+    "lrpt",
+    "sstv",
+    "vdes",
+    "wefax",
+    "wspr",
+]
+
+# SoapySDR pipeline; used when [rig.access] type = "sdr".
 [trx-server.sdr]
 sample_rate = 1920000
 bandwidth = 1500000
@@ -68,17 +120,38 @@ wfm_deemphasis_us = 50
 center_offset_hz = 100000
 channels = []
 max_virtual_channels = 4
+spectrum_fft_size = 1024
+spectrum_interval_ms = 50

+# "auto" for hardware AGC, or "manual".
 [trx-server.sdr.gain]
 mode = "auto"
 value = 30.0

+# Software squelch on demodulated audio.
 [trx-server.sdr.squelch]
 enabled = false
 threshold_db = -65.0
 hysteresis_db = 3.0
 tail_ms = 180

+# Impulse-noise suppression on the IQ stream.
+[trx-server.sdr.noise_blanker]
+enabled = false
+threshold = 10.0
+
+# Timeout and buffer tuning.  The defaults suit most setups.
+[trx-server.timeouts]
+command_exec_timeout_ms = 10000
+poll_refresh_timeout_ms = 8000
+io_timeout_ms = 10000
+request_timeout_ms = 12000
+rig_task_channel_buffer = 32
+
+# Client: exposes the radio to users.
+[trx-client]
+
+# Labels shown in the web UI.
 [trx-client.general]
 callsign = "N0CALL"
 website_url = "https://haxx.space"
@@ -86,24 +159,52 @@ website_name = "haxx.space"
 ais_vessel_url_base = "https://www.vesselfinder.com/?mmsi="
 log_level = "info"

+# Legacy single-remote form; prefer [[remotes]] below.
 [trx-client.remote]
-url = "192.168.1.100:9000"
-rig_id = "hf"
 poll_interval_ms = 750
+spectrum_interval_ms = 50

 [trx-client.remote.auth]
+
+[[trx-client.remotes]]
+name = "home-hf"
+url = "192.168.1.100:4530"
+rig_id = "hf"
+poll_interval_ms = 750
+spectrum_interval_ms = 50
+
+[trx-client.remotes.auth]
 token = "my-token"

+[[trx-client.remotes]]
+name = "home-vhf"
+url = "192.168.1.100:4530"
+rig_id = "vhf"
+poll_interval_ms = 750
+spectrum_interval_ms = 50
+
+[trx-client.remotes.auth]
+token = "my-token"
+
+# Web UI.  default_rig_name and the per-rig maps are keyed by the
+# [[remotes]] name, not the server-side rig id.
 [trx-client.frontends.http]
 enabled = true
 listen = "127.0.0.1"
 port = 8080
-default_rig_id = "hf"
+default_rig_name = "home-hf"
 initial_map_zoom = 10
 spectrum_coverage_margin_hz = 50000
 spectrum_usable_span_ratio = 0.9200000166893005
 show_sdr_gain_control = true
+bandplan_enabled = true
+bandplan_region = "iaru_r1"
+decode_history_retention_min = 1440

+[trx-client.frontends.http.decode_history_retention_min_by_rig]
+
+# Passphrase login for the web UI.  rx_passphrase_file and
+# control_passphrase_file keep the secrets out of this file.
 [trx-client.frontends.http.auth]
 enabled = false
 rx_passphrase = "rx-passphrase-example"
@@ -113,6 +214,7 @@ session_ttl_min = 480
 cookie_secure = false
 cookie_same_site = "Lax"

+# Hamlib-compatible TCP interface, one listener per rig.
 [trx-client.frontends.rigctl]
 enabled = false
 listen = "127.0.0.1"
@@ -120,6 +222,7 @@ port = 4532

 [trx-client.frontends.rigctl.rig_ports]

+# JSON-over-TCP control interface.
 [trx-client.frontends.http_json]
 enabled = true
 listen = "127.0.0.1"
@@ -128,12 +231,16 @@ port = 0
 [trx-client.frontends.http_json.auth]
 tokens = []

+# Where to fetch the audio stream from.
 [trx-client.frontends.audio]
 enabled = true
 server_port = 4531

+[trx-client.frontends.audio.rig_urls]
+
 [trx-client.frontends.audio.rig_ports]

+# Play RX audio on a local sound device and capture TX from one.
 [trx-client.frontends.audio.bridge]
 enabled = false
 bitrate_bps = 192000