Twilio WhatsApp Destination

When to use this destination type

Choose TWILIO_WHATSAPP when the receiver target is Twilio Messages API for WhatsApp. Destinations are outbound delivery targets: they do not decide whether a source request should be accepted, and they do not own connection filters or transformations. They own where the final delivery goes and how FastHook should authenticate, pace, disable, and inspect that delivery.

A destination can be reused by multiple connections when several source branches should feed the same receiver. Reuse keeps receiver capacity, credentials, and attempt evidence attached to one destination id.

FastHook dashboard fields

In the dashboard, create a destination, set Destination Type to TWILIO_WHATSAPP, then fill the fields below.

API config fields

The REST API stores destination-specific behavior under config. Use PATCH for focused edits and PUT only when your request contains the full config you want to keep.

{
  "name": "ops-whatsapp-alerts",
  "type": "TWILIO_WHATSAPP",
  "config": {
    "from": "whatsapp:+14155238886",
    "to": "whatsapp:{{payload.customer.phone}}",
    "body_template": "FastHook event {{event_id}}\n{{payload}}",
    "messaging_service_sid": null,
    "content_sid": null,
    "content_variables_template": null,
    "auth_type": "TWILIO_AUTH_TOKEN",
    "auth": {
      "account_sid": "ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
      "auth_token": "twilio-auth-token"
    },
    "rate_limit": 1,
    "rate_limit_period": "second"
  }
}

curl -X POST "https://api.fasthook.io/v1/destinations" \
  -H "Authorization: Bearer $FASTHOOK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "name": "ops-whatsapp-alerts",
  "type": "TWILIO_WHATSAPP",
  "config": {
    "from": "whatsapp:+14155238886",
    "to": "whatsapp:{{payload.customer.phone}}",
    "body_template": "FastHook event {{event_id}}\n{{payload}}",
    "messaging_service_sid": null,
    "content_sid": null,
    "content_variables_template": null,
    "auth_type": "TWILIO_AUTH_TOKEN",
    "auth": {
      "account_sid": "ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
      "auth_token": "twilio-auth-token"
    },
    "rate_limit": 1,
    "rate_limit_period": "second"
  }
}'

Authentication

Destination authentication is outbound. It helps the receiver trust or accept FastHook delivery, and it is separate from source authentication that verifies the original webhook producer.

• Twilio Account SID and Auth Token
• Twilio WhatsApp Sandbox join flow for testing
• Approved Twilio WhatsApp sender or Messaging Service for production

HTTP methods and rate limit

This destination type uses the methods below for delivery attempts. Rate limits apply at the destination boundary, so every connection that targets the same destination shares that capacity.

Rate limit: Locked to 1 request per second.

Delivery behavior

• FastHook renders message templates per delivery and sends through Twilio's Messages API.
• WhatsApp addresses use the whatsapp:+E.164 format. Rendered template values can omit the prefix and FastHook will add it.
• For Sandbox testing, each recipient must send the join code from the exact WhatsApp account that should receive messages.
• A Twilio API 201 response means Twilio accepted the message. Final delivery can still move through queued, sent, delivered, read, or failed in Twilio message logs.
• Outside WhatsApp's 24-hour customer service window, Twilio requires an approved content template. Use Content SID and Content variables for that flow.
• Twilio WhatsApp destinations are locked to 1 request per second to avoid message bursts.

Setup checklist

1. For Sandbox testing, open Twilio Console, activate the WhatsApp Sandbox, and copy the Sandbox join code.
2. Have the recipient send join <your sandbox code> to +14155238886 from the exact WhatsApp or WhatsApp Business account that should receive messages.
3. Create a FastHook destination and choose TWILIO_WHATSAPP as the destination type.
4. Set From sender to whatsapp:+14155238886 for the Sandbox, or to an approved Twilio WhatsApp sender or Messaging Service SID for production.
5. Set To recipient to the target WhatsApp address, or use a template token that renders to a +E.164 phone number.
6. Paste the Twilio Account SID and Auth Token from Twilio Console API keys & tokens.
7. For production business-initiated messages outside the customer service window, add a Messaging Service SID, Content SID, and Content variables JSON.
8. Connect only WhatsApp-worthy events through filters before routing to the destination.

Troubleshooting

Related docs

• Destinations
• Twilio source type
• Twilio webhooks
• Filter and route events
• Control throughput
• Twilio WhatsApp Sandbox
• Twilio error 63015
• Twilio error 63031
• API reference