github/copilot-sdk · error · RuntimeError

Client not connected

Error message

Client not connected

What it means

Lifecycle guard in CopilotClient.create_session: the method was called before the client finished connecting to the CLI runtime, or after the connection dropped, so there is no transport to carry the session.create request. It is a local sentinel precondition error, not a remote failure.

Solutions

1. Use `async with CopilotClient(...) as client` or await the connect/start call before creating sessions
2. Confirm the CLI process launched successfully (path, version, startup logs) - a failed start leaves the client disconnected
3. Reconnect after a disconnect before reusing the same client instance

When it happens

Trigger: Thrown at python/copilot/client.py:2826 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of github/copilot-sdk@cd8cf15dc3 (2026-09-09). Data as JSON: /api/errors/a154490ebfbcb114. Report an issue: GitHub.

Appendix: source

Thrown at python/copilot/client.py:2826

        if memory is not None:
            payload["memory"] = _memory_to_wire(memory)

        if canvases:
            payload["canvases"] = [c.to_dict() for c in canvases]
        if request_canvas_renderer is not None:
            payload["requestCanvasRenderer"] = request_canvas_renderer
        if request_extensions is not None:
            payload["requestExtensions"] = request_extensions
        if extension_sdk_path is not None:
            payload["extensionSdkPath"] = extension_sdk_path
        if extension_info is not None:
            payload["extensionInfo"] = extension_info.to_dict()
        if canvas_provider is not None:
            payload["canvasProvider"] = canvas_provider.to_dict()

        if not self._client:
            raise RuntimeError("Client not connected")

        total_start = time.perf_counter()
        # For cloud sessions, let the CLI/server assign the session id and
        # register the session lazily once the response arrives. For non-cloud
        # sessions we generate the id client-side (when the caller didn't
        # supply one) so the session can be registered BEFORE the RPC — the
        # CLI may issue session-scoped requests (e.g. ``sessionFs.writeFile``
        # for workspace metadata) during ``session.create`` processing, before
        # it has sent the response.
        use_server_generated_id = cloud is not None and session_id is None
        local_session_id: str | None = (
            None if use_server_generated_id else (session_id or str(uuid.uuid4()))
        )
        if local_session_id is not None:
            payload["sessionId"] = local_session_id
        github_token_provider_registration_id = self._register_github_token_provider(
            github_token_provider, local_session_id
        )

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