Developers
sendlz API documentation
One REST API for WhatsApp and email. Bearer keys, idempotent sends, signed webhooks, per-key rate limits and an OpenAPI spec you can generate clients from.
- 6 core
- endpoints cover 90% of use
- 5 SDKs
- Node, Python, PHP, Java, Go
- OpenAPI 3.1
- spec published
What you need to know before the first call
Auth
Bearer token per key. Keys are scoped by capability and environment; rotate without downtime using overlapping keys.
Idempotency
Send an Idempotency-Key header; retries within 24 hours return the original message id rather than duplicating.
Rate limits
Per-key limits with standard RateLimit headers, and a burst allowance that follows your Meta messaging tier.
Webhooks
HMAC-signed, replay-protected, with at-least-once delivery and a 7-day replay window from the console.
Errors
Typed error codes with a docs URL per code — no guessing what error 4013 means.
Sandbox
A test number and test inbox that mirror production behaviour including template rejection and bounce events.
One REST call for WhatsApp. The same one for email.
Idempotent sends, signed webhooks, sandbox keys, per-key rate limits and an OpenAPI spec. Server SDKs for Node, Python, PHP, Java and Go, plus no-code via Shopify, WooCommerce, Zapier and Pabbly.
- POST /v1/messages
- POST /v1/email/send
- GET /v1/templates
- POST /v1/contacts
- GET /v1/reports/delivery
- POST /v1/webhooks
curl -X POST https://api.sendlz.com/v1/messages \
-H "Authorization: Bearer $SENDLZ_KEY" \
-H "Idempotency-Key: ord_48120_shipped" \
-d channel=whatsapp \
-d to=+919812345678 \
-d template=order_shipped_v3 \
-d vars[name]=Ananya \
-d vars[awb]=SL48120IN
{ "id": "msg_01JQ...", "status": "queued",
"category": "utility", "price": 0.115 }Send smarter. Sell faster.
Start free with 1,000 conversations. Bring your own Meta number or apply for a new one — we handle verification, templates and the green tick with you.