[FEATURE] Start routines from MCP Events emitted by connectors

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Routines can start only on a schedule (minimum 1 hour), an authenticated /fire call, or GitHub events. There is no way to react when something happens in a connected app.

My case: clean the Junk folder of a personal Outlook.com account as soon as a new email arrives. Microsoft Graph can push a notification, but it cannot call /fire (no custom headers, and it requires a validationToken handshake), so I had to self-host a Cloudflare Worker relay. The hourly schedule reacts up to 1 hour late and spends usage on empty runs.

Proposed Solution

Support the MCP Events extension (SEP-3415, io.modelcontextprotocol/events) in claude.ai connectors, starting with webhook mode:

• When a connected MCP server advertises events, let me pick one as a routine trigger: "Run this routine when connector X emits event Y".
• Claude hosts and verifies the callback URL, validates Standard Webhooks signatures, and renews the subscription before its TTL expires.
• The event payload reaches the routine as routine-fire-payload (untrusted data, like /fire text).
• Bursts are grouped into a single run, within the existing 30 runs/hour limit.

Alternative Solutions

• Self-hosted relay (Cloudflare Worker) that answers Graph's validation, groups bursts and calls /fire with the required headers. It works, but every user has to build and maintain one.
• Hourly schedule: up to 1 hour of delay and usage spent on empty runs.
• Channels: requires a local machine always on, a public tunnel and --dangerously-load-development-channels.
• A generic webhook trigger (URL with a secret + built-in validation handshakes) would also cover non-MCP senders.
• ChatGPT has supported MCP Events (webhook mode) since 2026-09-29.

Priority

High - Significant impact on productivity

Feature Category

MCP server integration

Use Case Example

1. A new email lands in my Outlook.com Junk folder.
2. Microsoft Graph notifies my MCP server, which emits the event "junk_email_received".
3. Claude receives the event and starts my "Outlook Junk" routine.
4. The routine uses the same connector's tools (list_junk, move_to_deleted) to move spam to Deleted Items.
5. Result: about 1–3 minutes of delay instead of up to 1 hour, and no runs when nothing arrives.

Additional Context

• MCP Events design: https://github.com/modelcontextprotocol/experimental-ext-triggers-events
• Listed under "Server-initiated events" in the MCP roadmap: https://modelcontextprotocol.io/development/roadmap
• Related: #94918 (API/webhook trigger for Cowork tasks)
• Separate request I plan to file: OAuth refresh-token credentials in cloud environments, so sessions never see tokens.