Ironfang Finance API problem type

`delivery_unavailable`

Delivery unavailable. HTTP 503.

What it means

Delivery destinations cannot be managed or used by this deployment at the moment. The outcome of any document is unchanged.

What to do

Retry after retry_after_seconds.

What the response carries

type: https://ironfang.uk/problems/delivery_unavailable, this page.
status: Always 503 for this code.
code: delivery_unavailable. Stable: branch on this, not on the wording of title or detail.
detail: What happened this time, safe to show to a person. It never carries invoice content.
request_id: The same value as the X-Ironfang-Request-ID header. Quote it to support.
retry_after_seconds: May be present, with a matching Retry-After header: wait that long before retrying.
outcome: Absent. This code is not a statement about any document.

Problems follow RFC 9457 and are served as application/problem+json. A validation finding is never a Problem: an invalid invoice is a successful response that lists its findings. See every problem type, the Finance guide and the OpenAPI contract.