fix(restart): preserve channel metadata across /restart so reply lands in thread

cmd_restart only persisted channel + chat_id across the os.execv boundary, so
when the new process announced "Restart completed" the OutboundMessage had
no Slack thread_ts and the reply fell back to the channel root.

Serialize msg.metadata into NANOBOT_RESTART_NOTIFY_METADATA, restore it on the
RestartNotice, and forward it to OutboundMessage so the completion message
follows the same routing as the original /restart invocation.

Made-with: Cursor

nanobot/channels/manager.py

@@ -172,6 +172,7 @@ class ChannelManager:
                 channel=notice.channel,
                 chat_id=notice.chat_id,
                 content=format_restart_completed_message(notice.started_at_raw),
+                metadata=dict(notice.metadata or {}),
             ),
         ))
 

nanobot/command/builtin.py

@@ -28,7 +28,11 @@ async def cmd_stop(ctx: CommandContext) -> OutboundMessage:
 async def cmd_restart(ctx: CommandContext) -> OutboundMessage:
     """Restart the process in-place via os.execv."""
     msg = ctx.msg
-    set_restart_notice_to_env(channel=msg.channel, chat_id=msg.chat_id)
+    set_restart_notice_to_env(
+        channel=msg.channel,
+        chat_id=msg.chat_id,
+        metadata=dict(msg.metadata or {}),
+    )
 
     async def _do_restart():
         await asyncio.sleep(1)

nanobot/utils/restart.py

@@ -2,12 +2,15 @@
 
 from __future__ import annotations
 
+import json
 import os
 import time
-from dataclasses import dataclass
+from dataclasses import dataclass, field
+from typing import Any
 
 RESTART_NOTIFY_CHANNEL_ENV = "NANOBOT_RESTART_NOTIFY_CHANNEL"
 RESTART_NOTIFY_CHAT_ID_ENV = "NANOBOT_RESTART_NOTIFY_CHAT_ID"
+RESTART_NOTIFY_METADATA_ENV = "NANOBOT_RESTART_NOTIFY_METADATA"
 RESTART_STARTED_AT_ENV = "NANOBOT_RESTART_STARTED_AT"
 
 
@@ -16,6 +19,7 @@ class RestartNotice:
     channel: str
     chat_id: str
     started_at_raw: str
+    metadata: dict[str, Any] = field(default_factory=dict)
 
 
 def format_restart_completed_message(started_at_raw: str) -> str:
@@ -30,11 +34,20 @@ def format_restart_completed_message(started_at_raw: str) -> str:
     return f"Restart completed{elapsed_suffix}."
 
 
-def set_restart_notice_to_env(*, channel: str, chat_id: str) -> None:
+def set_restart_notice_to_env(
+    *, channel: str, chat_id: str, metadata: dict[str, Any] | None = None,
+) -> None:
     """Write restart notice env values for the next process."""
     os.environ[RESTART_NOTIFY_CHANNEL_ENV] = channel
     os.environ[RESTART_NOTIFY_CHAT_ID_ENV] = chat_id
     os.environ[RESTART_STARTED_AT_ENV] = str(time.time())
+    if metadata:
+        try:
+            os.environ[RESTART_NOTIFY_METADATA_ENV] = json.dumps(metadata, default=str)
+        except (TypeError, ValueError):
+            os.environ.pop(RESTART_NOTIFY_METADATA_ENV, None)
+    else:
+        os.environ.pop(RESTART_NOTIFY_METADATA_ENV, None)
 
 
 def consume_restart_notice_from_env() -> RestartNotice | None:
@@ -42,9 +55,23 @@ def consume_restart_notice_from_env() -> RestartNotice | None:
     channel = os.environ.pop(RESTART_NOTIFY_CHANNEL_ENV, "").strip()
     chat_id = os.environ.pop(RESTART_NOTIFY_CHAT_ID_ENV, "").strip()
     started_at_raw = os.environ.pop(RESTART_STARTED_AT_ENV, "").strip()
+    metadata_raw = os.environ.pop(RESTART_NOTIFY_METADATA_ENV, "").strip()
     if not (channel and chat_id):
         return None
-    return RestartNotice(channel=channel, chat_id=chat_id, started_at_raw=started_at_raw)
+    metadata: dict[str, Any] = {}
+    if metadata_raw:
+        try:
+            parsed = json.loads(metadata_raw)
+        except (TypeError, ValueError):
+            parsed = None
+        if isinstance(parsed, dict):
+            metadata = parsed
+    return RestartNotice(
+        channel=channel,
+        chat_id=chat_id,
+        started_at_raw=started_at_raw,
+        metadata=metadata,
+    )
 
 
 def should_show_cli_restart_notice(notice: RestartNotice, session_id: str) -> bool:

tests/utils/test_restart.py

@@ -16,6 +16,7 @@ from nanobot.utils.restart import (
 def test_set_and_consume_restart_notice_env_roundtrip(monkeypatch):
     monkeypatch.delenv("NANOBOT_RESTART_NOTIFY_CHANNEL", raising=False)
     monkeypatch.delenv("NANOBOT_RESTART_NOTIFY_CHAT_ID", raising=False)
+    monkeypatch.delenv("NANOBOT_RESTART_NOTIFY_METADATA", raising=False)
     monkeypatch.delenv("NANOBOT_RESTART_STARTED_AT", raising=False)
 
     set_restart_notice_to_env(channel="feishu", chat_id="oc_123")
@@ -25,14 +26,42 @@ def test_set_and_consume_restart_notice_env_roundtrip(monkeypatch):
     assert notice.channel == "feishu"
     assert notice.chat_id == "oc_123"
     assert notice.started_at_raw
+    assert notice.metadata == {}
 
     # Consumed values should be cleared from env.
     assert consume_restart_notice_from_env() is None
     assert "NANOBOT_RESTART_NOTIFY_CHANNEL" not in os.environ
     assert "NANOBOT_RESTART_NOTIFY_CHAT_ID" not in os.environ
+    assert "NANOBOT_RESTART_NOTIFY_METADATA" not in os.environ
     assert "NANOBOT_RESTART_STARTED_AT" not in os.environ
 
 
+def test_restart_notice_preserves_metadata_across_env(monkeypatch):
+    monkeypatch.delenv("NANOBOT_RESTART_NOTIFY_CHANNEL", raising=False)
+    monkeypatch.delenv("NANOBOT_RESTART_NOTIFY_CHAT_ID", raising=False)
+    monkeypatch.delenv("NANOBOT_RESTART_NOTIFY_METADATA", raising=False)
+    monkeypatch.delenv("NANOBOT_RESTART_STARTED_AT", raising=False)
+
+    set_restart_notice_to_env(
+        channel="slack",
+        chat_id="C123",
+        metadata={"slack": {"thread_ts": "1700.42", "channel_type": "channel"}},
+    )
+
+    notice = consume_restart_notice_from_env()
+    assert notice is not None
+    assert notice.metadata == {
+        "slack": {"thread_ts": "1700.42", "channel_type": "channel"}
+    }
+    assert "NANOBOT_RESTART_NOTIFY_METADATA" not in os.environ
+
+
+def test_restart_notice_clears_stale_metadata(monkeypatch):
+    monkeypatch.setenv("NANOBOT_RESTART_NOTIFY_METADATA", '{"stale": true}')
+    set_restart_notice_to_env(channel="cli", chat_id="direct")
+    assert "NANOBOT_RESTART_NOTIFY_METADATA" not in os.environ
+
+
 def test_format_restart_completed_message_with_elapsed(monkeypatch):
     monkeypatch.setattr("nanobot.utils.restart.time.time", lambda: 102.0)
     assert format_restart_completed_message("100.0") == "Restart completed in 2.0s."