Invalid query
A query parameter is unknown, empty or outside its limit.
Public interface / Failure contract
Errors stay predictable and machine-readable.
Failures never become empty success responses and never disclose secrets, stack traces or private candidate data.
Not found
The requested versioned resource does not exist.
Method not allowed
The public data endpoints accept GET and HEAD only.
Rate limit exceeded
The configured Cloudflare limiter rejected the request.
Internal error
The request failed without exposing internal details.
Unavailable
A required durable service or production binding is absent.
Problem shape
{
"type": "https://neobankdb.com/problems/invalid-query",
"title": "Invalid query",
"status": 400,
"detail": "Human-readable boundary",
"instance": "/v1/providers"
}