Error codes

Public v2 errors are application/json. The type field is a bare token, not a URI — it groups related codes, and several codes deliberately share one. Branch on code, which is unique.

Code	Type	Shares type with	Also an auth code
`cancellation_conflict`	`conflict`	`conflict`	no
`conflict`	`conflict`	`cancellation_conflict`	yes
`event_history_expired`	`gone`	—	no
`forbidden`	`forbidden`	`workspace_suspended`	yes
`internal_error`	`internal_error`	—	no
`invalid_request`	`invalid_request`	—	yes
`not_found`	`not_found`	—	yes
`payload_too_large`	`payload_too_large`	—	no
`rate_limited`	`rate_limited`	—	yes
`service_unavailable`	`service_unavailable`	—	no
`unauthorized`	`unauthorized`	—	no
`unsupported_media_type`	`unsupported_media_type`	—	no
`workspace_suspended`	`forbidden`	`forbidden`	no

Response shape

{
  "type": "conflict",
  "code": "cancellation_conflict",
  "message": "a human-readable explanation",
  "request_id": "01JQ...",
  "details": null
}

Treat code as an open enumeration: new codes may be added without a major version, so always keep a default branch. The 33 authentication codes are documented separately under problem codes.