Errors

Every error is an RFC 9457 problem document, served as application/problem+json with a real HTTP status code:

{
  "type": "https://docs.haasapi.com/errors/exchange_not_found",
  "title": "Exchange not found",
  "status": 404,
  "detail": "Exchange 'NOPE' is not supported.",
  "code": "exchange_not_found",
  "instance": "6f1b2c3d4e5f60718293a4b5c6d7e8f9"
}

Match on code

code is the stable, machine-readable slug - the field your error handling should switch on. detail is for humans and may be reworded; code values never change meaning.

r = requests.get(url, headers=auth)
if not r.ok:
    problem = r.json()
    if problem["code"] == "invalid_cursor":
        cursor = None  # restart the walk
    elif problem["code"] == "temporarily_unavailable":
        retry_later()
    else:
        raise ApiError(problem["title"], problem["detail"])

The shared codes

Status	code	What to do
400	invalid_request	Fix the parameter named in detail
400	invalid_cursor	Restart pagination from the first page
401	unauthorized / invalid_api_key	Check the key - see Authentication
404	not_found	The path doesn’t exist
405	method_not_allowed	Wrong HTTP method for this path
503	temporarily_unavailable	Retry with the same request. Never discard your key on a 503
504	upstream_timeout	Retry; the backend took too long

Endpoint-specific codes (like exchange_not_found) are listed on each endpoint in the reference.

Reporting a problem

Every response carries an X-Request-Id header, and error bodies repeat it as instance. Quote that one identifier when contacting support and we can find your exact request.