fingerprintchecker (Python)

Install with pip install fingerprintchecker; import it as fpchecker.

Server SDK for FingerPrintChecker. Python 3.9+, standard-library HTTP, one runtime dependency (cryptography, for sealed results).

from fpchecker import FpChecker, unseal_result, verify_webhook_signature, FpCheckerApiError

fp = FpChecker(os.environ["FPCHECKER_SECRET_KEY"])
verdict = fp.check_eligibility({"visitorId": "v_..."})
if verdict.get("ok") is False:
    print("refused:", verdict.get("error") or verdict.get("reason"))

Client

FpChecker(secret_key, base_url="https://api.fpchecker.com", timeout=10, *, publishable_key=None) has one method per OpenAPI operationId, in snake_case: create_intent, get_challenge, identify, check_eligibility, release_eligibility, check_quota, bind_subject, relate_subjects, send_feedback, get_claim_flags, search_events, get_event, update_event, get_visitor, delete_visitor, get_health, get_status. Bodies and query parameters are plain dicts; responses are dicts.

• The secret key goes in the X-Secret-Key header, never in a URL, and is not shown by repr(). get_challenge and identify use the publishable key (publishable_key=) in X-Publishable-Key instead; get_health and get_status send no key.
• 2xx responses are returned as data, including refusals such as {"ok": False, "error": ...}. Check ok.
• Non-2xx raises FpCheckerApiError with status, code (error or reason from the body), retry_after (seconds) and body.
• Network failures and timeouts also raise FpCheckerApiError, with status 0, code "network_error" or "timeout", and the original exception as __cause__.
• Redirects are never followed (they would forward the secret key to another origin). base_url must be https, except localhost, 127.0.0.1 and [::1] (otherwise ValueError).
• timeout (positive finite seconds) applies per network operation (connect, each read), not to the whole call.
• Only GET requests retry (429, 5xx, network failures and timeouts; at most 2 retries, honouring Retry-After, wait capped at 10 s). POST, PATCH and DELETE are never retried.

Sealed results

result = unseal_result(identify_response["sealedResult"], [os.environ["FPC_SEALED_KEY"]])

Pass every active key (active and previous during rotation). Raises SealedResultError with .code of bad_format, unknown_key, decrypt_failed, invalid_key or unsupported_version.

Webhooks

# raw_body must be the exact bytes received, not a re-serialised object.
verify_webhook_signature(request.body, request.headers["FPC-Signature"], os.environ["FPC_WEBHOOK_SECRET"])

Raises WebhookSignatureError with .code of malformed_header, bad_signature, expired or future. tolerance_sec (default 300) must be a finite number >= 0, else TypeError / ValueError.

License

Apache-2.0