Send Messages

POST to Meta Graph API v24.0 with a Bearer token. Same shape for sandbox through the proxy and production direct.

The Basic Call

Every send is a POST to ${WHATSAPP_API_URL}/${WHATSAPP_PHONE_NUMBER_ID}/messages with Authorization: Bearer ${WHATSAPP_ACCESS_TOKEN} and a JSON body whose first key is messaging_product: "whatsapp".

The shape is identical for sandbox (through the HookMyApp proxy) and production (direct to Meta). For the full message-object reference see Meta's Cloud API docs.

curl Example

curl -X POST "${WHATSAPP_API_URL}/${WHATSAPP_PHONE_NUMBER_ID}/messages" \
  -H "Authorization: Bearer ${WHATSAPP_ACCESS_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{
    "messaging_product": "whatsapp",
    "to": "+15551234567",
    "type": "text",
    "text": { "body": "Hello from my app" }
  }'

Node/Express Example

Verbatim from the webhook starter kit.

export async function sendMessage(to, text) {
  const url = `${process.env.WHATSAPP_API_URL}/${process.env.WHATSAPP_PHONE_NUMBER_ID}/messages`;
  const res = await fetch(url, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${process.env.WHATSAPP_ACCESS_TOKEN}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      messaging_product: 'whatsapp',
      to,
      type: 'text',
      text: { body: text },
    }),
  });
  if (!res.ok) throw new Error(`WhatsApp API ${res.status}`);
  return res.json();
}

Templates Are Production-only

Sandbox blocks template sends.

The sandbox proxy rejects type: "template" messages. Test templates against a connected production WABA, not the sandbox.

Rate Limits And Retries

Meta enforces per-phone messaging tiers and per-WABA business-initiated-conversation quotas. HookMyApp passes rate-limit error responses through untouched so your retry logic sees them directly.

For current tier thresholds, pair rates, and the 429 retry contract, see Meta's rate-limit docs.

Next Steps

• Receive Webhooks: Handle the delivery and read receipts.
• Sandbox: Try the send flow end-to-end with a shared test number.