Sending Whatsapp

WhatsApp Messaging with Sendly

WhatsApp is a first-class Sendly channel: connect a number you own, then send through the same Messages endpoint as SMS with channel: "whatsapp".

Not yet generally available. WhatsApp is gated behind the whatsapp_channel rollout flag. Until it is enabled for your account, /api/v1/whatsapp/* endpoints return not_found (404) and WhatsApp sends via /api/v1/messages return 403 whatsapp_not_enabled. Ask Sendly to enable it before relying on these endpoints. WhatsApp always requires a live API key — test keys get 403 whatsapp_requires_live_key (delivery is never sandbox-simulated on this channel).

The two rules that shape everything

1. Connecting a number needs a human. The signup returns a connectUrl that a person must open in a browser and log in with Facebook to link their WhatsApp Business Account. You (the agent) cannot complete this step programmatically — hand the URL to the account owner, then poll until the status is active.
2. The 24-hour window decides what you can send. Free-form text and media only deliver while a customer-service window is open (it opens, and resets to 24 hours, each time the recipient messages your number). Outside a window, only a Meta-approved template delivers.

Quick start

import Sendly from "@sendly/node";

const sendly = new Sendly(process.env.SENDLY_API_KEY!);

const { senders } = await sendly.whatsapp.senders.list();
const from = senders.find((s) => s.status === "active")?.phoneNumber;

const { open } = await sendly.whatsapp.window({ from, to: "+15551234567" });

const message = open
  ? await sendly.messages.send({
      channel: "whatsapp",
      to: "+15551234567",
      from,
      text: "Your table is ready!",
    })
  : await sendly.messages.send({
      channel: "whatsapp",
      to: "+15551234567",
      from,
      template: {
        name: "order_shipped",
        language: "en_US",
        variables: { "1": "Sam", "2": "#4821" },
      },
    });

REST API

Base URL: https://sendly.live/api/v1

Connect a number (a human must finish this)

curl -X POST https://sendly.live/api/v1/whatsapp/signup \
  -H "Authorization: Bearer $SENDLY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"phoneNumber": "+15125550190"}'

Required: phoneNumber — an active number in your workspace (purchased or ported into Sendly).

Response:

{
  "id": "0b64c1de-…",
  "connectUrl": "https://sendly.live/whatsapp/connect/…",
  "status": "initiated"
}

Relay connectUrl to the account owner: they open it in a browser and sign in with Facebook to link their WhatsApp Business Account. A one-time $19 setup fee is charged (no monthly WhatsApp fee). Calling again for a number with an in-flight signup returns the same signup without charging again.

Poll the signup until it is active:

curl https://sendly.live/api/v1/whatsapp/signup/0b64c1de-… \
  -H "Authorization: Bearer $SENDLY_API_KEY"

Statuses: initiated (waiting on the human) → registering → active; failed (see failureReasons) or expired (connect URL lapsed — start again).

List connected senders

Check this before sending — it answers "which numbers can I send WhatsApp from?"

curl https://sendly.live/api/v1/whatsapp/senders \
  -H "Authorization: Bearer $SENDLY_API_KEY"

Response:

{
  "senders": [
    {
      "phoneNumber": "+15125550190",
      "displayName": "Acme Coffee",
      "status": "active",
      "qualityRating": null,
      "createdAt": "2026-07-30T09:12:00Z"
    }
  ]
}

status is pending (connection in progress), active (sendable), or suspended. displayName is the name recipients see (Meta-reviewed, null until set); qualityRating is Meta's quality signal (null until reported). An empty list means no number is WhatsApp-connected yet — run the signup flow above.

Check a 24-hour window

curl "https://sendly.live/api/v1/whatsapp/window?from=%2B15125550190&to=%2B15551234567" \
  -H "Authorization: Bearer $SENDLY_API_KEY"

Response: { "open": true, "expiresAt": "2026-07-31T09:12:00Z" } — or { "open": false, "expiresAt": null }, in which case send a template.

Send a message

Same endpoint as SMS. Provide exactly one of text, mediaUrls, or template:

curl -X POST https://sendly.live/api/v1/messages \
  -H "Authorization: Bearer $SENDLY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "whatsapp",
    "to": "+15551234567",
    "from": "+15125550190",
    "template": {
      "name": "order_shipped",
      "language": "en_US",
      "variables": { "1": "Sam", "2": "#4821" }
    }
  }'

• Free-form text (text, max 4096 bytes) — window-bound. 1 credit.
• Media (mediaUrls, exactly one publicly reachable HTTPS URL) — window-bound; an optional text becomes the caption (max 1024 bytes). 1 credit.
• Template (template) — works regardless of the window; the template must be APPROVED. Priced by category and destination country.

from is required — there is no default-sender fallback on this channel. to must be in E.164.

Templates

Templates are Meta-reviewed message formats (review typically takes 24–48h) and the only way to start a conversation or reach someone whose window has closed.

Three categories, which drive review rules and per-message pricing:

• authentication — OTP/verification codes (no URLs or media allowed). Cheapest.
• utility — transactional updates tied to an existing customer interaction.
• marketing — promotions. Priced highest, and Meta currently pauses marketing template delivery to US (+1) recipients — plan US promotional traffic on SMS instead.

Meta may reclassify a template it deems miscategorized; the category on the record is authoritative.

curl -X POST https://sendly.live/api/v1/whatsapp/templates \
  -H "Authorization: Bearer $SENDLY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "sender": "+15125550190",
    "name": "order_shipped",
    "language": "en_US",
    "category": "utility",
    "body": "Hi {{1}}, your order {{2}} has shipped!",
    "examples": { "1": "Sam", "2": "#4821" }
  }'

Every {{n}} placeholder in the body needs an example value. List templates and their review status with GET /api/v1/whatsapp/templates; only APPROVED templates are sendable.

Rejection recovery: template names are locked for ~30 days once submitted (even after deletion). If Meta rejects a template, edit it with PATCH /api/v1/whatsapp/templates/{id} and resubmit under the same name — do not delete and re-create it.

Before-send checklist

1. GET /whatsapp/senders — is the from number listed with status active?
2. GET /whatsapp/window?from=…&to=… — window open? Free-form is fine (1 credit).
3. Window closed? GET /whatsapp/templates — pick an APPROVED template and send with template.

Node.js SDK

import Sendly from "@sendly/node";
const sendly = new Sendly(process.env.SENDLY_API_KEY!);

const signup = await sendly.whatsapp.signup.create({ phoneNumber: "+15125550190" });
const status = await sendly.whatsapp.signup.get(signup.id);

const { senders } = await sendly.whatsapp.senders.list();
const { open, expiresAt } = await sendly.whatsapp.window({ from: "+15125550190", to: "+15551234567" });

const { templates } = await sendly.whatsapp.templates.list();
await sendly.whatsapp.templates.create({
  sender: "+15125550190",
  name: "order_shipped",
  language: "en_US",
  category: "UTILITY",
  body: "Hi {{1}}, your order {{2}} has shipped!",
  examples: { "1": "Sam", "2": "#4821" },
});
await sendly.whatsapp.templates.update("wat_xxx", { body: "…" }); // rejected-template fix

Error handling

Full reference

• WhatsApp docs: https://sendly.live/docs/whatsapp
• WhatsApp API reference: https://sendly.live/docs/whatsapp-api
• Templates guide: https://sendly.live/docs/whatsapp/templates