different-ai/openwork · error · SafeProbeFailure

jsonrpc_error

jsonrpc_error

Error message

jsonrpc_error

What it means

parseJsonRpcResult throws SafeProbeFailure("jsonrpc_error") when the response payload contains an 'error' member, meaning the remote MCP server rejected the request with a JSON-RPC error object instead of a result. The probe deliberately collapses the remote error's details into a safe fixed code so provider-controlled strings are never surfaced.

Source

Thrown at apps/server/src/agent-context-cloud-probe.ts:531

    }
    if (line.startsWith(":")) continue;
    const colon = line.indexOf(":");
    const field = colon < 0 ? line : line.slice(0, colon);
    const rawValue = colon < 0 ? "" : line.slice(colon + 1);
    const value = rawValue.startsWith(" ") ? rawValue.slice(1) : rawValue;
    if (field === "event") event = value;
    if (field === "data") data.push(value);
  }
  dispatch();
  if (messages.length !== 1) throw new SafeProbeFailure("invalid_json");
  return messages[0];
}

function parseJsonRpcResult(payload: unknown, requestId: string): Record<string, unknown> {
  if (!isRecord(payload) || payload.jsonrpc !== "2.0") {
    throw new SafeProbeFailure("invalid_jsonrpc_envelope");
  }
  if (Object.hasOwn(payload, "error")) throw new SafeProbeFailure("jsonrpc_error");
  if (payload.id !== requestId) throw new SafeProbeFailure("request_id_mismatch");
  if (!isRecord(payload.result)) throw new SafeProbeFailure("invalid_jsonrpc_envelope");
  return payload.result;
}

function requireSupportedProtocolVersion(initializeResult: Record<string, unknown>): void {
  const version = initializeResult.protocolVersion;
  if (typeof version !== "string" || version.length === 0 || version.length > MAX_PROTOCOL_HEADER_LENGTH) {
    throw new SafeProbeFailure("invalid_jsonrpc_envelope");
  }
  if (version !== MCP_PROTOCOL_VERSION) throw new SafeProbeFailure("unsupported_protocol_version");
}

function validateCatalog(rpcResult: Record<string, unknown>): { toolIds: string[]; totalToolCount: number } {
  if (rpcResult.nextCursor !== undefined && rpcResult.nextCursor !== null) {
    throw new SafeProbeFailure("pagination_unsupported");
  }
  if (!Array.isArray(rpcResult.tools) || rpcResult.tools.length > MAX_TOOL_COUNT) {

View on GitHub (pinned to 2b7df46e8a)

Solutions

1. Check the bearer token/credentials the probe is sending are valid and authorized for this MCP server
2. Confirm the server supports the initialize and tools/list methods
3. Inspect server-side logs for the JSON-RPC error code it returned
4. Ensure the probe's JSON-RPC request bodies match the current MCP spec

Example fix

null

// No reliable pre-call check: JSON-RPC errors depend on server state (auth, method support).
// Pre-validate what you can: send valid credentials and only supported methods.

function isJsonRpcError(v: unknown): boolean {
  return typeof v === "object" && v !== null && Object.hasOwn(v as Record<string, unknown>, "error");
}

try {
  const result = parseJsonRpcResult(payload, requestId);
} catch (e) {
  if (e instanceof SafeProbeFailure && e.code === "jsonrpc_error") {
    // rotate credentials / check method support; inspect server logs for the underlying error code
  } else throw e;
}

When it happens

Trigger: Server responds with {"jsonrpc":"2.0","id":...,"error":{"code":...,"message":...}} for the initialize or tools/list request.

Common situations: Invalid or expired bearer token rejected at protocol level; server does not support the requested MCP method; server-side rate limiting or policy denial; malformed request built by an outdated client.

Related errors

• invalid_jsonrpc_envelope
• request_id_mismatch
• MCP_INITIALIZE
• MCP_PROVIDER_DECLARED_ERROR
• invalid_mcp_token_payload

AI-assisted analysis of different-ai/openwork@2b7df46e8a (2026-09-01). Data as JSON: /api/errors/bda63f06c9d33bcc. Report an issue: GitHub.