Developers

WhatsApp and OTP in a few lines of code

One API key, plain JSON, signed webhooks. Send messages and verification codes from your CRM, shop or app.

send a WhatsApp message

curl -X POST https://signalxas.com/api/v1/whatsapp/messages \
  -H "Authorization: Bearer sx_live_…" \
  -H "Content-Type: application/json" \
  -d '{"to":"447700900123","text":"Your order has shipped 📦"}'

→ 202 {"id":123,"status":"QUEUED","to":"447700900123"}

Simple auth

Create keys in your portal; send them as a Bearer token. Only a hash is stored.

Text, media, templates

Images and documents by URL; approved templates on official API numbers.

OTP built in

Send and verify codes: hashed, 5-minute expiry, 5 tries, rate-limited.

Signed webhooks

Incoming messages and delivery receipts, signed with HMAC-SHA256.

Messages

message types

# image
{"to":"…","image":{"url":"https://…/photo.jpg","caption":"New stock"}}
# document
{"to":"…","document":{"url":"https://…/invoice.pdf","filename":"invoice.pdf"}}
# template (official Cloud API numbers)
{"to":"…","template":{"name":"order_ready","language":"en_US","params":["Ann"]}}
# send from a given number
{"to":"…","text":"…","number":"<number id>"}

status

GET /api/v1/whatsapp/messages/123
→ {"id":123,"status":"DELIVERED"}   QUEUED → SENT → DELIVERED → READ | FAILED

GET /api/v1/whatsapp/numbers
→ {"numbers":[{"id":"…","kind":"qr","phone":"…","status":"CONNECTED"}]}

OTP & webhooks

one-time codes

POST /api/v1/otp/send    {"to":"447700900123","brand":"Acme","length":6}
→ 202 {"id":"…","expiresIn":300}

POST /api/v1/otp/verify  {"to":"447700900123","code":"482913"}
→ {"valid":true}

webhook we POST to you

X-SignalXas-Event: message
X-SignalXas-Signature: sha256=<HMAC-SHA256(secret, body)>

{"event":"message","number":{"id":"…","phone":"…"},
 "message":{"id":124,"from":"447700900123","name":"Ann",
            "type":"text","body":"Hi!","at":"…"}}

Errors are plain

400 bad input · 401 wrong key · 402 balance too low · 409 number not linked · 429 limit reached — always with a readable “error” message.

Start building