Errors

Typical error body:

{
  "error": "not_allowed",
  "message": "..."
}

When contacting support, send client_id, ext_id if any, UTC time, and the path.

HTTP status

HTTP	Meaning
`200`	Success
`400`	Invalid request
`401`	Missing / invalid assertion or access token
`403`	Not allowed (wrong product, closed rail, or another agent’s resource)
`409`	Business cannot execute (balance, `ext_id` conflict, product)
`429`	Rate limit
`503`	Unavailable (caution, under_attack, or Agent API disabled)

Unknown /api/... functions return opaque 403 (and may temporarily freeze the agent). Do not probe Partner or human-only RPCs.

Code / situation	Notes
`not_allowed`	Convert at tier 0, withdraw, C2C, Stars, Partner URLs
`insufficient_balance`	Catalog debit
`rate_limited`	Register / token / RPS caps
`unavailable`	503 on register (medium) or the whole channel (under_attack / kill-switch)