diff --git a/src/trx-server/src/audio.rs b/src/trx-server/src/audio.rs
index 7e807e8..2f2a04e 100644
--- a/src/trx-server/src/audio.rs
+++ b/src/trx-server/src/audio.rs
@@ -12,6 +12,7 @@ use std::time::{Duration, Instant};
 
 use bytes::Bytes;
 use num_complex::Complex;
+use tokio::io::AsyncWriteExt;
 use tokio::net::{TcpListener, TcpStream};
 use tokio::sync::{broadcast, mpsc, watch};
 use tracing::{error, info, warn};
@@ -19,9 +20,10 @@ use tracing::{error, info, warn};
 use trx_ais::AisDecoder;
 use trx_aprs::AprsDecoder;
 use trx_core::audio::{
-    read_audio_msg, write_audio_msg, AudioStreamInfo, AUDIO_MSG_AIS_DECODE, AUDIO_MSG_APRS_DECODE,
-    AUDIO_MSG_CW_DECODE, AUDIO_MSG_FT8_DECODE, AUDIO_MSG_RX_FRAME, AUDIO_MSG_STREAM_INFO,
-    AUDIO_MSG_TX_FRAME, AUDIO_MSG_VDES_DECODE, AUDIO_MSG_WSPR_DECODE,
+    read_audio_msg, write_audio_msg, write_audio_msg_buffered, AudioStreamInfo,
+    AUDIO_MSG_AIS_DECODE, AUDIO_MSG_APRS_DECODE, AUDIO_MSG_CW_DECODE, AUDIO_MSG_FT8_DECODE,
+    AUDIO_MSG_RX_FRAME, AUDIO_MSG_STREAM_INFO, AUDIO_MSG_TX_FRAME, AUDIO_MSG_VDES_DECODE,
+    AUDIO_MSG_WSPR_DECODE,
 };
 use trx_core::decode::{
     AisMessage, AprsPacket, DecodedMessage, Ft8Message, VdesMessage, WsprMessage,
@@ -44,6 +46,14 @@ const FT8_SAMPLE_RATE: u32 = 12_000;
 const DECODE_AUDIO_GATE_RMS: f32 = 2.5e-4;
 const AUDIO_STREAM_ERROR_LOG_INTERVAL: Duration = Duration::from_secs(60);
 const AUDIO_STREAM_RECOVERY_DELAY: Duration = Duration::from_secs(1);
+const HISTORY_REPLAY_FLUSH_INTERVAL: usize = 64;
+
+fn current_timestamp_ms() -> i64 {
+    match std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH) {
+        Ok(dur) => dur.as_millis() as i64,
+        Err(_) => 0,
+    }
+}
 
 struct StreamErrorLogger {
     label: &'static str,
@@ -838,13 +848,16 @@ pub async fn run_aprs_decoder(
                         apply_decode_audio_gate(&mut mono);
 
                         was_active = true;
-                        for pkt in decoder.process_samples(&mono) {
+                        for mut pkt in decoder.process_samples(&mono) {
                             if let Some(logger) = decode_logs.as_ref() {
                                 logger.log_aprs(&pkt);
                             }
                             if !pkt.crc_ok {
                                 continue;
                             }
+                            if pkt.ts_ms.is_none() {
+                                pkt.ts_ms = Some(current_timestamp_ms());
+                            }
                             histories.record_aprs_packet(pkt.clone());
                             let _ = decode_tx.send(DecodedMessage::Aprs(pkt));
                         }
@@ -1604,13 +1617,23 @@ async fn handle_audio_client(
     let info_json = serde_json::to_vec(&stream_info).map_err(std::io::Error::other)?;
     write_audio_msg(&mut writer, AUDIO_MSG_STREAM_INFO, &info_json).await?;
 
+    let history_replay_started_at = Instant::now();
+    let mut replayed_history_count = 0usize;
+    let mut pending_history_flush = 0usize;
+
     // Send APRS history to newly connected client.
     let history = histories.snapshot_ais_history();
     for msg in history {
         let msg = DecodedMessage::Ais(msg);
         let msg_type = AUDIO_MSG_AIS_DECODE;
         if let Ok(json) = serde_json::to_vec(&msg) {
-            write_audio_msg(&mut writer, msg_type, &json).await?;
+            write_audio_msg_buffered(&mut writer, msg_type, &json).await?;
+            replayed_history_count += 1;
+            pending_history_flush += 1;
+            if pending_history_flush >= HISTORY_REPLAY_FLUSH_INTERVAL {
+                writer.flush().await?;
+                pending_history_flush = 0;
+            }
         }
     }
     let history = histories.snapshot_vdes_history();
@@ -1618,7 +1641,13 @@ async fn handle_audio_client(
         let msg = DecodedMessage::Vdes(msg);
         let msg_type = AUDIO_MSG_VDES_DECODE;
         if let Ok(json) = serde_json::to_vec(&msg) {
-            write_audio_msg(&mut writer, msg_type, &json).await?;
+            write_audio_msg_buffered(&mut writer, msg_type, &json).await?;
+            replayed_history_count += 1;
+            pending_history_flush += 1;
+            if pending_history_flush >= HISTORY_REPLAY_FLUSH_INTERVAL {
+                writer.flush().await?;
+                pending_history_flush = 0;
+            }
         }
     }
     // Send APRS history to newly connected client.
@@ -1627,7 +1656,13 @@ async fn handle_audio_client(
         let msg = DecodedMessage::Aprs(pkt);
         let msg_type = AUDIO_MSG_APRS_DECODE;
         if let Ok(json) = serde_json::to_vec(&msg) {
-            write_audio_msg(&mut writer, msg_type, &json).await?;
+            write_audio_msg_buffered(&mut writer, msg_type, &json).await?;
+            replayed_history_count += 1;
+            pending_history_flush += 1;
+            if pending_history_flush >= HISTORY_REPLAY_FLUSH_INTERVAL {
+                writer.flush().await?;
+                pending_history_flush = 0;
+            }
         }
     }
     // Send FT8 history to newly connected client.
@@ -1636,7 +1671,13 @@ async fn handle_audio_client(
         let msg = DecodedMessage::Ft8(msg);
         let msg_type = AUDIO_MSG_FT8_DECODE;
         if let Ok(json) = serde_json::to_vec(&msg) {
-            write_audio_msg(&mut writer, msg_type, &json).await?;
+            write_audio_msg_buffered(&mut writer, msg_type, &json).await?;
+            replayed_history_count += 1;
+            pending_history_flush += 1;
+            if pending_history_flush >= HISTORY_REPLAY_FLUSH_INTERVAL {
+                writer.flush().await?;
+                pending_history_flush = 0;
+            }
         }
     }
     // Send WSPR history to newly connected client.
@@ -1645,9 +1686,26 @@ async fn handle_audio_client(
         let msg = DecodedMessage::Wspr(msg);
         let msg_type = AUDIO_MSG_WSPR_DECODE;
         if let Ok(json) = serde_json::to_vec(&msg) {
-            write_audio_msg(&mut writer, msg_type, &json).await?;
+            write_audio_msg_buffered(&mut writer, msg_type, &json).await?;
+            replayed_history_count += 1;
+            pending_history_flush += 1;
+            if pending_history_flush >= HISTORY_REPLAY_FLUSH_INTERVAL {
+                writer.flush().await?;
+                pending_history_flush = 0;
+            }
         }
     }
+    if pending_history_flush > 0 {
+        writer.flush().await?;
+    }
+    if replayed_history_count > 0 {
+        info!(
+            "Audio client {} replayed {} history messages in {:?}",
+            peer,
+            replayed_history_count,
+            history_replay_started_at.elapsed()
+        );
+    }
 
     // Spawn RX + decode forwarding task (shares the writer)
     let mut rx_sub = rx_audio.subscribe();