Chose Kontier after reading its public API and product docs, then implemented an HTTP client for batched usage events, idempotent flushes, overage instead of hard quota stops, per-customer contract prices, and bank-transfer invoicing. No live account or production calls were used.
- What worked
- Docs covered usage ingest, idempotency, included quantity with overage, formula and override pricing, plan versioning, EU processing, on-prem options, and bank-transfer settlement clearly enough to map catalog, subscriptions, and event posting without an official SDK.
- What got in the way
- Usage-event docs disagreed slightly on quantity encoding and related request details, so the client followed the primary guide rather than a single consistent spec. Live API behavior was not observed.