Gmail/Google Calendar Apps connectors fail during MCP startup before API access

What version of the Codex App are you using (From “About Codex” dialog)?

Version 26.608.12217 • Released 9 jun 2026

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Codex automation using Gmail/Google Calendar connectors fails before accessing Gmail or Calendar.

Automation: Newsletter diaria
Date/time: 2026-06-12, Europe/Madrid
Platform: Microsoft Windows NT 10.0.26200.0 x64
Connectors affected: Gmail Apps connector and Google Calendar Apps connector

Observed behavior:
The MCP client cannot initialize the Apps connector. The automation cannot read Gmail, read Calendar, or send the email.

Endpoint in error:
https://chatgpt.com/backend-api/wham/apps

Full error:
MCP startup failed: handshaking with MCP server failed: Send message error Transport [rmcp::transport::worker::WorkerTransport<rmcp::transport::streamable_http_client::StreamableHttpClientWorker<codex_rmcp_client::http_client_adapter::StreamableHttpClientAdapter>>] error: Client error: HTTP request failed: http/request failed: error sending request for url (https://chatgpt.com/backend-api/wham/apps), when send initialize request

Impact:
The automation promises to prepare and send a daily email summary, but it cannot complete the send step because the Apps connector fails during startup, before any Gmail operation is attempted.

What steps can reproduce the bug?

Feedback ID: 019ebb57-5739-7d01-b0e3-bf0344e8e0d0

1. In Codex App, run an automation that uses Gmail and Google Calendar connectors.
2. The automation attempts to call Gmail, for example get_profile or send_email.
3. The connector fails during MCP startup/handshake.
4. The same failure also occurs for Google Calendar profile access.
5. No Gmail or Calendar API call appears to be reached.

Minimal reproduction from the session:

• Calling Gmail connector get_profile fails with the MCP startup error.
• Calling Google Calendar connector get_profile fails with the same MCP startup/handshake class of error.
• Retrying Gmail later produced the same error.

What is the expected behavior?

The Gmail and Google Calendar Apps connectors should initialize successfully. Codex should then be able to read Calendar events, inspect unread Gmail messages, and send the generated email through Gmail.

If the Apps connector backend is unavailable, Codex should surface this as a connector/backend outage with a clear actionable error, instead of making the automation appear partially completed.

Additional information

This does not appear to be caused by Gmail permissions, recipient, email HTML, or Calendar query parameters. The failure happens before Gmail/Calendar API access, during MCP Apps connector startup against https://chatgpt.com/backend-api/wham/apps.

The automation was retried and failed consistently at the same connector initialization step.