​

Pre-call Variables

​

1. Declare the variable names on the agent

PUT /api/v2/agent/{id}
Authorization: Bearer rg_live_...
Content-Type: application/json

{
  "variables": ["callee_name", "mobile_number"]
}

​

2. Reference them in the prompt or greeting

You are calling {{callee_name}} regarding their order. Be friendly,
acknowledge them by name, and confirm we're reaching them on
{{mobile_number}}.

Hi {{callee_name}}, this is your friendly assistant.

​

3. Supply per-call values

POST /api/v2/calls/start
Authorization: Bearer rg_live_...
Content-Type: application/json

{
  "agent_id": "...",
  "to_number": "+919876543210",
  "provider": "twilio",
  "connection_id": "9b7f1c44-c87f-4f0c-9124-3c802a9c1a20",
  "variables": {
    "callee_name": "Sajal",
    "mobile_number": "+919876543210"
  }
}

​

4. Echoed in the webhook

​

Behavior

• Missing values render as empty strings. A prompt that says Hi {{callee_name}}! produces Hi ! if callee_name is omitted. The platform never errors on missing variables.
• Type coercion is automatic. Non-string values in the request body ({ age: 25 }, { active: true }) are stringified before substitution.
• Inbound calls receive no variables field by default; placeholders in the prompt render empty.
• Custom functions can read variables. Values supplied at call start are available to your configured custom functions, so handlers such as CRM lookup or calendar booking can use fields like customer_id directly.

​

Next steps