Errors

Upsign follows usual HTTP semantics: check the status code first, then parse the JSON body when present. Many routes return a structured object with code and message; others return a simple error string—see the examples below.

HTTP status

Typical responses:

Status	Meaning
400	Validation / missing headers / bad ID format
401	Missing or invalid X-Api-Key, or other auth failures called out for specific routes
403	Forbidden (e.g. webhook routes require admin)
404	Resource not found or not accessible (often same JSON as “not found” for ACL)
500	Server / configuration error

JSON shapes

Many document routes return structured errors:

{
  "code": "invalid_id_format",
  "message": "Expected a document ID starting with \"doc_\"."
}

Webhook routes sometimes return:

{ "error": "Forbidden. Admin access required." }

Per-operation status codes, code values, and response schemas are defined in the API reference (OpenAPI).