chat_cancel_target_not_found
HTTP status: 404
Type: not_found
When it fires
POST /v1/chat/completions/{id}/cancel was called with an id that doesn’t exist for the requesting team. Same Stripe-style stance as image / video 404s — no existence leak across teams.
How to recover
Verify theid you’re passing came from a POST /v1/chat/completions response your team made. Don’t retry — the resource doesn’t exist (or isn’t yours).