PagerDuty Events API 400 invalid routing key in CI

The PagerDuty Events API v2 returns HTTP 400 with status invalid event and an error like "Length of 'routing_key' is incorrect (should be 32 characters)" or "routing_key not found" when the routing_key in the payload is missing, malformed, or from a non-Events-API integration.

What this error means

A trigger event to events.pagerduty.com returns HTTP 400 with a message about the routing key. No incident is created.

PagerDuty Events API

< HTTP/1.1 400 Bad Request
{"status":"invalid event","message":"Event object is invalid","errors":["Length of 'routing_key' is incorrect (should be 32 characters)"]}

Common causes

The key is not an Events API v2 integration key

A REST API token or an integration key from a different integration type is not a valid 32-character Events API v2 routing key.

The secret is empty or truncated

A missing or partially pasted PAGERDUTY_ROUTING_KEY fails the length or lookup check.

How to fix it

Use the Events API v2 integration key

On the PagerDuty service, add an integration of type Events API v2.
Copy its 32-character Integration Key (routing key).
Store it as PAGERDUTY_ROUTING_KEY and send it in the payload.

Terminal

jq -n --arg k "$PAGERDUTY_ROUTING_KEY" '{
  routing_key:$k, event_action:"trigger",
  payload:{summary:"CI build failed",source:"github-actions",severity:"error"}}' |
curl -sS -X POST https://events.pagerduty.com/v2/enqueue \
  -H 'Content-Type: application/json' --data @-

Reference the key from a secret

Inject the routing key through the step env so it is never hard-coded.

.github/workflows/ci.yml

env:
  PAGERDUTY_ROUTING_KEY: ${{ secrets.PAGERDUTY_ROUTING_KEY }}

How to prevent it

Use an Events API v2 integration key, not a REST token.
Store the 32-character key in a secret and verify its length.
Send a test trigger when wiring a new service integration.