Error Handling - Docs2work

Code	HTTP	Meaning	Action
`VALIDATION_FAILED`	400	Graph errors block activation	POST /validate, read errors[], fix each one, retry
`MISSING_FORM_ID`	400	Node has no form_id	POST /forms then PATCH /nodes/:id
`MISSING_EDGE`	400	conditional/split needs more edges	Add edges for all outcome paths
`ORPHANED_NODE`	400	Node has no incoming edges	Add edge or DELETE /nodes/:id
`NO_END_REACHABLE`	400	Branch has no end node	Add end node and connecting edge
`MISSING_ASSIGNEE`	400	Human node has no assignee	PATCH /nodes/:id with assigneeEmail
`TRIGGER_NOT_SET`	400	No trigger configured	POST /trigger before activating
`CONFLICT`	409	Node ID exists or session activated	New ID or new session
`EXPIRED`	410	Session past 24 hours	Create new session
`INTERNAL_ERROR`	500	Activation rolled back	Nothing committed. Retry.

General principles

On a 400 error, read the field-level error details and reason about corrections before retrying. Never retry blindly. On a 500, nothing was committed to production — the org is unchanged. It is safe to retry.