agentscope-ai/agentscope · warning · LookupError

Session '{session_id}' not found.

Error message

Session '{session_id}' not found.

What it means

ChatService.interrupt raises LookupError when storage.get_session(user_id, agent_id, session_id) returns None, i.e. no session matches that triple. Because sessions are scoped per user and agent, a technically existing session id still fails if the user_id or agent_id in the call doesn't match the session's owner.

Source

Thrown at src/agentscope/app/_service/_chat.py:558

        Args:
            user_id (`str`):
                Authenticated caller's user id.
            session_id (`str`):
                Target session id.
            agent_id (`str`):
                Agent that owns the session.

        Raises:
            LookupError:
                The session does not exist.
        """
        session = await self._storage.get_session(
            user_id,
            agent_id,
            session_id,
        )
        if session is None:
            raise LookupError(f"Session '{session_id}' not found.")

        if await self._message_bus.is_locked(
            MessageBusKeys.session_lock(session_id),
        ):
            await self._message_bus.publish(
                MessageBusKeys.session_interrupt_channel(),
                {"session_id": session_id},
            )
            return

        await enqueue_run_trigger(
            self._message_bus,
            user_id=user_id,
            session_id=session_id,
            agent_id=agent_id,
            kind=MessageBusKeys.WAKEUP_KIND_RESUME,
            inputs=UserInterruptEvent(reply_id=session.state.reply_id),
        )

View on GitHub (pinned to e90f1c7592)

Solutions

1. Confirm the session exists via the session list/get endpoint for that exact user and agent before interrupting
2. Check that user_id and agent_id in the call match the session's owners
3. Refresh the session id from the current conversation state instead of caching it long-term
4. Treat LookupError on interrupt as 'nothing to interrupt' and surface a friendly message

Example fix

# before
await chat_service.interrupt(user_id, agent_id, session_id)  # LookupError
# after
if await storage.get_session(user_id, agent_id, session_id) is not None:
    await chat_service.interrupt(user_id, agent_id, session_id)
else:
    logger.info("Session already gone; nothing to interrupt")

session = await chat_client.get_session(user_id, agent_id, session_id)
if session is None:
    logger.info("Session gone; nothing to interrupt")
    return
await chat_client.interrupt(user_id, agent_id, session_id)

try:
    await chat_service.interrupt(user_id, agent_id, session_id)
except LookupError:
    pass  # session already ended; nothing to interrupt

When it happens

Trigger: Calling the session interrupt endpoint with a session_id that doesn't exist, or with a mismatched user_id/agent_id pair (e.g. interrupting another user's session or passing the wrong agent).

Common situations: Stale session ids held in a frontend after the session ended and was cleaned up; retrying an interrupt after the run completed and the session was reaped; passing an admin user_id while the session belongs to a regular user; copy-pasting ids across environments.

Related errors

• Session {session_id!r} not found.
• Session {session_id!r} already has an active chat run in thi
• Session {session_id!r} not found for agent {agent_id!r}.
• Knowledge base {knowledge_base_id!r} not found.
• Credential {record.data.embedding_model_config.credential_id

AI-assisted analysis of agentscope-ai/agentscope@e90f1c7592 (2026-08-28). Data as JSON: /api/errors/8096696ec10d3451. Report an issue: GitHub.