Solutions
The pragmatic integration playbook for cashflow POST APIs
End-to-end engineering guide: auth, envelopes, error handling, retries, and observability for teams shipping cash endpoints to production.
This page is for lead engineers who own the integration — not executive summaries. It connects quickstart examples to production concerns like key rotation, 429 backoff, schema drift, and how to log payloads without leaking secrets.
Baseline architecture
Keep secrets server-side only. Proxy Cashytics calls through your API gateway so mobile apps never embed keys. Attach `account_id` to your internal tenant ids for traceability.
Standardize a single envelope builder module so webhooks, batch jobs, and interactive dashboards do not fork validation logic.
Error semantics you should handle first
Read errors & limits before launch: understand 429 on free tiers, schema validation failures, and unknown endpoint responses from typos. Map each to user-visible guidance in your dashboard.
Log correlation ids on your side even if the vendor payload does not include them — you will need them during incidents.
Observability and PII
Never log full envelopes in production unless redacted. Log hashes, endpoint names, latency, and truncated ids. Store full JSON only in restricted buckets when audits require it.
Testing strategy
Golden-file tests per endpoint with anonymized envelopes. Add regression tests when narratives change meaningfully so product teams get notified before deploy.
Schema drift and versioning
Pin your client to documented schema versions in CI. When Cashytics adds optional fields, your parser should tolerate unknown keys so deploys are forward-compatible.
Run contract tests against staging weekly even if production did not change — vendors evolve schemas more often than product teams expect.
FAQ
- Should we call Cashytics from the browser?
- No. Always call from your servers with server-held keys. The playground is the only browser-safe path without secrets.
- How do we rotate API keys without dropping traffic?
- Issue new keys first, dual-write or dual-read during overlap, monitor 401 rates, then revoke old keys. Automate rotation calendars so keys do not expire during holidays.