can1357/oh-my-pi · error · ToolError

Invalid cmux socket response: missing ok flag

Error message

Invalid cmux socket response: missing ok flag

What it means

A parsed object reply that contains neither ok === true nor ok === false has no verdict flag, so #parseResponse throws this ToolError. It is the last-resort envelope validation: the peer produced a JSON object but not a cmux response object.

Source

Thrown at packages/coding-agent/src/tools/browser/cmux/socket-client.ts:403

			throw new ToolError(line);
		}
		let payload: unknown;
		try {
			payload = JSON.parse(line);
		} catch (err) {
			throw new ToolError(`Invalid cmux socket JSON response: ${err instanceof Error ? err.message : String(err)}`);
		}
		if (!payload || typeof payload !== "object") {
			throw new ToolError("Invalid cmux socket response: expected object");
		}
		const response = payload as { ok?: unknown; result?: unknown; error?: CmuxErrorPayload };
		if (response.ok === true) {
			return (response.result ?? {}) as Record<string, unknown>;
		}
		if (response.ok === false) {
			throw new ToolError(formatCmuxError(response.error));
		}
		throw new ToolError("Invalid cmux socket response: missing ok flag");
	}

	#handleSocketFailure(err: Error): void {
		if (this.#disposed) return;
		this.#connected = false;
		this.#connectPromise = null;
		this.#rejectAll(new ToolError(`cmux socket error: ${err.message}`));
		this.#socket?.destroy();
		this.#socket = null;
	}

	#handleSocketClose(): void {
		const hadPendingRead = this.#lineWaiters.length > 0;
		this.#connected = false;
		this.#connectPromise = null;
		this.#socket = null;
		if (!this.#disposed && hadPendingRead) {
			this.#rejectAll(new ToolError("cmux socket closed"));

View on GitHub (pinned to 9690622007)

Solutions

1. Align client and daemon versions so the {ok,...} envelope contract holds on both ends
2. Verify the socketPath targets the cmux control socket, not an event/notification stream
3. Capture the offending raw line in daemon logs and fix or report the envelope regression

function hasOkFlag(v: unknown): v is { ok: boolean } {
  return typeof v === "object" && v !== null && "ok" in v && typeof (v as { ok: unknown }).ok === "boolean";
}

try {
  return await client.request(method, params);
} catch (err) {
  if (err instanceof ToolError && err.message === "Invalid cmux socket response: missing ok flag") {
    // envelope/protocol mismatch: align versions or check you're on the control socket
  }
  throw err;
}

When it happens

Trigger: Daemon (or another JSON service on the socket) returns objects like {"jsonrpc":"2.0","id":...} or event/notification objects lacking ok; protocol skew where newer daemons emit a different envelope for some methods.

Common situations: Mixing client and daemon versions; connecting to a different JSON-over-line service that happens to emit objects; daemon bug emitting notification frames interleaved into request replies.

Related errors

• Invalid cmux socket response: expected object
• Replacement text is not valid UTF-8: {err}
• Missing or invalid field "${field}" in catalog: ${filePath}
• Marketplace catalog at ${filePath} must be a JSON object
• rpc frame must be an object

AI-assisted analysis of can1357/oh-my-pi@9690622007 (2026-08-31). Data as JSON: /api/errors/8aa926099946c256. Report an issue: GitHub.