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API

APIs & Integrations

REST design, webhooks, authentication, idempotency and talking to couriers and ERPs.

Idempotency Keys for a POST Endpoint That Must Survive Retries A client that times out cannot know whether the write committed, so it retries. A unique key and a stored response are what make that retry harmless. API 24 SEP 2026 · 8M Webhook Retries, and Why They Must Not Create a Second Order Senders retry because they cannot tell a slow receiver from a dead one. Here is the receiver that survives the fifth delivery of the same event. API 10 AUG 2026 · 8M Versioning a Plugin REST API Without Breaking Other People's Code A version bump tells clients something changed but not what. How to tell additive changes from breaking ones, and how to retire a route on a schedule you publish. API 27 JUN 2026 · 7M Authenticating a Machine Client Against the WordPress REST API Cookie auth and X-WP-Nonce assume a browser session. What to use for server-to-server clients, how to store the credential, and why revocation needs a row. API 05 MAR 2026 · 9M Designing the JSON Your Integration Sends Out A webhook payload is an API contract with the same obligations as a REST response. What belongs in the envelope, and what a fat payload quietly freezes. API 03 DEC 2025 · 8M