rate_limited
HTTP 429
A real rate limit, and the only one we have. It covers the two routes that hand something out to a caller who has not paid: POST /v1/account/register, capped per source per hour because it is open and mints a credential, and POST /v1/account/domain/verify, capped per account per hour because it makes an outbound request to an address the caller chooses. Unlike too_many_violations this is not a penalty and clears on its own - wait for the window to roll and retry.
Response shape
{
"type": "https://cogdepot.com/problems/rate_limited",
"title": "<short human-readable summary>",
"status": 429,
"detail": "<what happened on this occurrence>",
"reason": "rate_limited"
}Branch on reason. The title is prose and may be reworded; reason is the stable contract.