fix: support Slack thread targets in send_message

tests/tools/test_send_message_tool.py

@@ -143,6 +143,41 @@ def test_resolved_telegram_topic_name_preserves_thread_id(self):
             force_document=False,
         )
 
+    def test_slack_thread_target_preserves_thread_ts(self):
+        chat_id, thread_id, is_explicit = _parse_target_ref(
+            "slack",
+            "C0AUUMPP7D1:1778566499.343239",
+        )
+
+        assert chat_id == "C0AUUMPP7D1"
+        assert thread_id == "1778566499.343239"
+        assert is_explicit is True
+
+    def test_send_to_platform_passes_slack_thread_id(self):
+        slack_cfg = SimpleNamespace(enabled=True, token="test", extra={})
+
+        async def _run():
+            with patch("tools.send_message_tool._send_slack", new=AsyncMock(return_value={"success": True})) as slack_send:
+                result = await _send_to_platform(
+                    Platform.SLACK,
+                    slack_cfg,
+                    "C0AUUMPP7D1",
+                    "hello",
+                    thread_id="1778566499.343239",
+                    media_files=[],
+                    force_document=False,
+                )
+                slack_send.assert_awaited_once_with(
+                    "test",
+                    "C0AUUMPP7D1",
+                    "hello",
+                    thread_id="1778566499.343239",
+                )
+                return result
+
+        result = asyncio.run(_run())
+        assert result["success"] is True
+
     def test_display_label_target_resolves_via_channel_directory(self, tmp_path):
         config, telegram_cfg = _make_config()
         cache_file = tmp_path / "channel_directory.json"

tools/send_message_tool.py

@@ -27,7 +27,9 @@
 # because the API requires a conversation ID. To DM a user you must first call
 # conversations.open to obtain a D... ID. Without this gate, Slack IDs fall
 # through to channel-name resolution, which only matches by name and fails.
-_SLACK_TARGET_RE = re.compile(r"^\s*([CGD][A-Z0-9]{8,})\s*$")
+# Optional suffix supports threaded replies via Slack thread_ts, e.g.
+# slack:C0123456789:1778566499.343239.
+_SLACK_TARGET_RE = re.compile(r"^\s*([CGD][A-Z0-9]{8,})(?::(\d{10,}(?:\.\d+)?))?\s*$")
 _WEIXIN_TARGET_RE = re.compile(r"^\s*((?:wxid|gh|v\d+|wm|wb)_[A-Za-z0-9_-]+|[A-Za-z0-9._-]+@chatroom|filehelper)\s*$")
 _YUANBAO_TARGET_RE = re.compile(r"^\s*((?:group|direct):[^:]+)\s*$")
 # Discord snowflake IDs are numeric, same regex pattern as Telegram topic targets.
@@ -133,7 +135,7 @@ async def _send_telegram_message_with_retry(bot, *, attempts: int = 3, **kwargs)
             },
             "target": {
                 "type": "string",
-                "description": "Delivery target. Format: 'platform' (uses home channel), 'platform:#channel-name', 'platform:chat_id', or 'platform:chat_id:thread_id' for Telegram topics and Discord threads. Examples: 'telegram', 'telegram:-1001234567890:17585', 'discord:999888777:555444333', 'discord:#bot-home', 'slack:#engineering', 'signal:+155****4567', 'matrix:!roomid:server.org', 'matrix:@user:server.org', 'yuanbao:direct:<account_id>' (DM), 'yuanbao:group:<group_code>' (group chat)"
+                "description": "Delivery target. Format: 'platform' (uses home channel), 'platform:#channel-name', 'platform:chat_id', or 'platform:chat_id:thread_id' for Telegram topics, Discord threads, and Slack thread_ts replies. Examples: 'telegram', 'telegram:-1001234567890:17585', 'discord:999888777:555444333', 'discord:#bot-home', 'slack:#engineering', 'slack:C0123456789:1778566499.343239', 'signal:+155****4567', 'matrix:!roomid:server.org', 'matrix:@user:server.org', 'yuanbao:direct:<account_id>' (DM), 'yuanbao:group:<group_code>' (group chat)"
             },
             "message": {
                 "type": "string",
@@ -332,7 +334,7 @@ def _parse_target_ref(platform_name: str, target_ref: str):
     if platform_name == "slack":
         match = _SLACK_TARGET_RE.fullmatch(target_ref)
         if match:
-            return match.group(1), None, True
+            return match.group(1), match.group(2), True
     if platform_name == "weixin":
         match = _WEIXIN_TARGET_RE.fullmatch(target_ref)
         if match:
@@ -699,7 +701,10 @@ async def _send_to_platform(platform, pconfig, chat_id, message, thread_id=None,
     last_result = None
     for chunk in chunks:
         if platform == Platform.SLACK:
-            result = await _send_slack(pconfig.token, chat_id, chunk)
+            if thread_id is not None:
+                result = await _send_slack(pconfig.token, chat_id, chunk, thread_id=thread_id)
+            else:
+                result = await _send_slack(pconfig.token, chat_id, chunk)
         elif platform == Platform.WHATSAPP:
             result = await _send_whatsapp(pconfig.extra, chat_id, chunk)
         elif platform == Platform.SIGNAL:
@@ -1120,7 +1125,7 @@ async def _send_discord(token, chat_id, message, thread_id=None, media_files=Non
         return _error(f"Discord send failed: {e}")
 
 
-async def _send_slack(token, chat_id, message):
+async def _send_slack(token, chat_id, message, thread_id=None):
     """Send via Slack Web API."""
     try:
         import aiohttp
@@ -1134,10 +1139,15 @@ async def _send_slack(token, chat_id, message):
         headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
         async with aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=30), **_sess_kw) as session:
             payload = {"channel": chat_id, "text": message, "mrkdwn": True}
+            if thread_id:
+                payload["thread_ts"] = str(thread_id)
             async with session.post(url, headers=headers, json=payload, **_req_kw) as resp:
                 data = await resp.json()
                 if data.get("ok"):
-                    return {"success": True, "platform": "slack", "chat_id": chat_id, "message_id": data.get("ts")}
+                    result = {"success": True, "platform": "slack", "chat_id": chat_id, "message_id": data.get("ts")}
+                    if thread_id:
+                        result["thread_id"] = str(thread_id)
+                    return result
                 return _error(f"Slack API error: {data.get('error', 'unknown')}")
     except Exception as e:
         return _error(f"Slack send failed: {e}")