For developers

Send and receive WhatsApp messages from any application.

Link a WhatsApp number once, then send text, images and documents over a documented REST API and react to delivery receipts and incoming messages through signed webhooks. Built for products that serve many tenants.

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curl -X POST https://api.whatstig.com/v1/messages \
  -H "Authorization: Bearer $WHATSTIG_API_KEY" \
  -H "Idempotency-Key: order-4512-shipped" \
  -H "Content-Type: application/json" \
  -d '{
    "instanceId": "wa_01jq8x7y2z3a4b5c6d7e8f9g0h",
    "recipient": "923001234567",
    "type": "text",
    "content": { "text": "Your order has shipped." },
    "clientReference": "order-4512"
  }'

HTTP/1.1 202 Accepted
{ "id": "msg_01jq…", "status": "QUEUED", "clientReference": "order-4512" }

The message log: outbound and inbound messages per instance with statuses such as read, sent, failed and received, and client references. — Messaging API & webhooksDashboard screenshot · sample business

Messaging API & webhooks

What you get

Connect by QR or pairing code: Create an instance, scan a QR code or enter a pairing code, and follow its status live. Sessions survive restarts and deployments without a new scan.
Text, images and documents: Upload media or import it from a public URL, then reference it when sending. Inbound media can be stored for you.
Idempotent sends: Retry any send safely with an Idempotency-Key: duplicates return the original response instead of a second message.
Honest delivery tracking: Queued, sent, delivered and read statuses with a per-message history that marks each step confirmed or inferred.
Signed webhooks: At-least-once delivery from a transactional outbox, HMAC signatures, retries with backoff, delivery logs and replay.
Scoped API keys: Least-privilege scopes, rotation and instant revocation. Secrets are shown once and stored only as keyed hashes.
Multi-tenant by design: Map each of your tenants to an instance with externalReference. Projects isolate products and environments.
Events for everything: Messages, conversations, campaigns, leads, deals and follow-ups all emit webhook events, so your systems stay in sync.
SDKs and OpenAPI: Official TypeScript (@whatstig/sdk) and .NET (WhatsTig.Client) clients generated from the OpenAPI 3.1 contract, plus a Postman collection.

How it works

01Create an API keyPick only the scopes your integration needs.
02Link a numberCreate an instance and scan its QR code, or send your customer a connect link.
03Send over HTTPPOST /v1/messages with an Idempotency-Key. Messages are durably queued and sent asynchronously.
04React to eventsVerify the signature of each webhook and handle delivery receipts and incoming messages.