Guides

• Authentication — API keys vs OAuth2 vs JWT login — when to use which.
• Errors — Error envelope, common error codes, troubleshooting.
• Idempotency — When and how to use Idempotency-Key.
• Pagination — page_size limits, response envelope, iteration recipes for invoices and customers.
• Rate limits — Token bucket per identity, plan-tier budgets, 429 + Retry-After handling.
• Receiving invoices — Inbound Peppol path through Oxalis, validation, storage, and how integrators consume the document.
• Sandbox — How to test against non-production data.
• Sending invoices — Full lifecycle from customer lookup → draft → validate → send → track.
• Versioning — /api/v1 path-versioning, deprecation policy, breaking-change definition.
• Webhooks — Subscribing endpoints, signature verification, retry policy.