Changelog

We treat /v1 as a forever-stable surface. Breaking changes get a new prefix (/v2) and a long deprecation window. Additions and bug fixes land in /v1 continuously.

2026-05 — MVP launch

• Public OpenAPI 3.1 spec at /openapi.json.
• llms.txt + llms-full.txt at the marketing root.
• Stripe-style Scalar API reference under /docs/api.
• 117 endpoints documented across 22 tags.
• Webhook event catalog: 19 events.
• Stable error code set: 26 codes (see Errors).

2026-04 — Webhook signing v1

• HMAC-SHA256 signing on every outbound delivery.
• Headers: X-WhatIsUp-Signature, X-WhatIsUp-Event, X-WhatIsUp-Event-Id, X-WhatIsUp-Correlation-Id.
• 5 retry attempts with exponential backoff.
• BullMQ-based delivery dispatcher; per-host concurrency cap.
• Webhook envelope carries api_version: 2026-04.

2026-03 — Channel lifecycle hardening

• Strict state-machine transitions enforced server-side (invalid_lifecycle_transition error code).
• Optimistic concurrency on lifecycle writes (concurrent_modification error code).
• POST /v1/channels/{id}/pair-code as a QR alternative.

2026-02 — Groups + Communities

• Full Whapi-shape group surface (16 endpoints).
• Communities (6 endpoints).
• Inbound group webhook events.

2026-01 — Initial public beta

• Channels, messages, contacts, chats, presence, profile, media, webhooks, API keys, rate limits, status, SSE events.
• Pair-by-QR.
• Plan: Trial / Starter / Pro.

What's next

• Header-based Idempotency-Key (P1).
• Newsletter posting UX docs (P1).
• Sandbox / test-mode environment (P2).
• Calls list + history (P2).
• Stories list + view tracking (P3).

Track the full gap analysis in our internal WhatsApp capability matrix.