Scheduled triggers stopped attaching MCP connectors to sessions (~Apr 1)

Bug Description

Scheduled triggers (remote triggers) with MCP connectors configured stopped injecting those connectors into sessions around April 1, 2026. The same trigger config that worked through March 31 began failing on April 1 — sessions no longer have access to the MCP tools.

Timeline

• Mar 25: Triggers created with Datadog + Notion MCP connectors
• Mar 29–31: All runs succeeded — MCP tools (e.g. search_datadog_rum_events, notion-create-pages) were available in sessions
• Apr 1: Runs began failing — sessions report "No matching deferred tools found" for all MCP tools
• Apr 1–3: Every scheduled and manual trigger run fails identically

What the session sees

The agent searches for MCP tools via ToolSearch and gets:

ToolSearch select:search_datadog_rum_events,notion-create-pages
No matching deferred tools found

ToolSearch datadog notion claude.ai
No matching deferred tools found

ToolSearch *
No matching deferred tools found

The MCP tools simply aren't present in the session at all.

Trigger configuration

The mcp_connections field is correctly set on the trigger:

"mcp_connections": [
  {
    "connector_uuid": "25913c1c-33dc-4adb-9d59-ddf650efae85",
    "name": "Datadog",
    "url": "https://mcp.datadoghq.com/api/unstable/mcp-server/mcp"
  },
  {
    "connector_uuid": "70853fa2-0b6b-4ff0-80ad-a7eb599000a5",
    "name": "Notion",
    "url": "https://mcp.notion.com/mcp"
  }
]

Both connectors show as connected in Settings > Connectors.

What we tried (none helped)

1. Recreating triggers from scratch — new trigger with identical config fails the same way
2. Disconnecting and reconnecting both Notion and Datadog connectors in Settings
3. Adding MCP tool names to allowed_tools (e.g. mcp__Datadog__search_datadog_rum_events) — no effect
4. Logging out and back into claude.ai — no effect
5. Manual trigger runs via API (POST /v1/code/triggers/{id}/run) — same failure

Working vs failing session examples

| Session | Date | Status | MCP Tools |
|---------|------|--------|-----------|
| 01CVoGuwMoijokdmqh5eUb4M | Mar 31 | ✅ Success | Available |
| 01T3nVnHVcKJ1JExMxHaaHgC | Apr 1 | ❌ Failed | Not found |
| 01Gf7QHaqZTHHBtTTGLnTdUm | Apr 3 | ❌ Failed | Not found |
| 015GbR2P31RKGhKSd8x2FKJH | Apr 3 | ❌ Failed | Not found |
| 014e2NphozyPBJkuVNEVbJFP | Apr 3 | ❌ Failed | Not found |

Trigger IDs

• trig_01SgwdJV38vXpY65P4Lzb6GF (original prod — has both working and failing runs)
• trig_01EDfETzjcVTAZ4b8mGn6ayL (recreated prod-v2 — fails)
• trig_01TFy4g3X8VahPaQWRcKQQin (original UAT — same issue)

Environment

• Organization: Moment
• Account: Peter Woo
• Environment ID: env_01Q15whscPienrPUnHV7eN8H

Expected behavior

MCP connectors listed in mcp_connections on a trigger should be attached to the session when the trigger fires, making their tools available — as was working through March 31.