Errors - Communicate Developer

Errors use a stable code for program logic and an error string for people.

{
  "error": "Invalid request body",
  "code": "request_body_invalid",
  "details": [
    {
      "code": "too_big",
      "message": "Message must contain at most 4000 characters",
      "path": "message"
    }
  ]
}

Status	Meaning
`400`	Malformed JSON or invalid input
`401`	Missing, invalid, or revoked API key
`403`	Credential lacks the operation’s required scope
`402`	Billing is paused or credits are exhausted
`404`	Agent not found in the key’s workspace
`409`	Agent inactive, model unavailable, or idempotency conflict
`429`	Rate limit exceeded
`503`	Agent temporarily unavailable during transfer
`500`	Unexpected server failure

OAuth token errors use the standard error field, including invalid_client, invalid_scope, invalid_target, and unsupported_grant_type.