WhatsApp Webhooks: Complete Developer Guide with Omdaa API

Webhooks turn WhatsApp into a real-time event stream for your backend, n8n, Zapier, or AI agents. This guide uses Omdaa API — free forever, no message limits.

Series: Free Forever WhatsApp Dev · Docs: omdaa.com/whatsapp-webhooks

Why webhooks?

Polling is slow and wasteful. With webhooks you get instant events:

• message / message.received — inbound messages
• session — connected / disconnected
• Delivery & status updates for outbound messages

Perfect for n8n, Zapier, custom Node servers, or Cursor MCP.

Step 1: Install the SDK

``bash npm install @omdaafreeapi/omdaa-api-client `

Step 2: Set your webhook URL

`javascript const { OmdaaClient } = require('@omdaafreeapi/omdaa-api-client');

const client = new OmdaaClient({ apiKey: process.env.OMDAA_API_KEY });

await client.webhooks.set({ url: 'https://your-server.com/webhook', events: ['message.received', 'session'], enabled: true, });

await client.webhooks.test(); `

cURL alternative:

`bash curl -X POST "https://omdaa.com/api/v1/webhooks" \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "url": "https://your-server.com/webhook", "events": ["message.received", "session"], "enabled": true }' `

Or configure from Dashboard → Webhooks / MCP tool set_webhook.

Step 3: Verify signatures (recommended)

Omdaa signs payloads with HMAC-SHA256. Validate before processing:

` X-Webhook-Signature: sha256= `

Compute HMAC-SHA256 over the raw request body with your webhook secret. Reject mismatches with 401.

Step 4: Handle events

`javascript app.post('/webhook', express.raw({ type: '*/*' }), (req, res) => { // verify signature on req.body (Buffer) first const payload = JSON.parse(req.body.toString('utf8')); const { event, data } = payload;

if (event === 'message.received' || event?.includes('message')) { console.log('From:', data?.from, 'Text:', data?.text || data?.message?.body); }

res.sendStatus(200); // ack fast — process async }); `

Built-in reliability

Connect to n8n / Zapier

1. Import integrations/n8n/omdaa-whatsapp-inbound.workflow.json 2. Point webhook URL to https://omdaa.com/n8n/webhook/omdaa-whatsapp 3. Or use a Zapier Catch Hook — see the Zapier tutorial

Troubleshooting

Next steps

1. Create free account 2. Connect WhatsApp session 3. Add Omdaa AI auto-replies 4. Cursor MCP catalog

Omdaa API — Free Forever. Real-time WhatsApp events without Meta Cloud API complexity.