Redial API Documentation

Version: v1

Overview

The Redial API is an end-to-end solution for placing AI-powered phone calls.

Without it, developers would have to build and maintain three separate services to integrate AI calling into their products:

1. An async WebSocket service for the OpenAI Realtime Audio API,
2. A WebSocket handler for Twilio or another telephony provider, and
3. A robust, fault-tolerant scheduling system to coordinate these calls.

Redial eliminates these complexities by combining all three services into a single, synchronous API. This significantly reduces development overhead and infrastructure cost.

With Redial, you can easily schedule, manage, and retrieve the results of AI phone calls through a simple API interface.

Base URL

https://api.redialapi.com/v1/

Authentication

All requests must include a Bearer token in the Authorization header.

Authorization: Bearer YOUR_API_KEY

Response Format

All responses are returned in JSON format.

Endpoints

• Schedule a Call
• Cancel a Call
• Check Call Status
• Get Transcript

1. Schedule a Call

Endpoint: POST /call/schedule

Request Body

{
  "who_to_call": "string",              // Phone number to call
  "when": 1714070400,                   // Epoch time in seconds, or 0 to place the call ASAP
  "model": "gpt-4o-realtime-preview",   // or "gpt-4o-mini-realtime-preview"
  "instructions": "string",             // Instructions for the model
  "custom_llm_config": {                // Optional: LLM-specific settings
    "voice": "alloy",
    "turn_detection": false
  }
}

Note: custom_llm_config aligns with OpenAI’s realtime audio API settings.

Response

{
  "event_id": "string",
  "status": "scheduled",  // or "error_scheduling"
  "error": null
}

2. Cancel a Call

Endpoint: POST /call/cancel

Request Body

{
  "event_id": "string"
}

Response

{
  "success": true // or false
}

3. Check Status of a Call

Endpoint: GET /call/status

Query Parameters

?event_id=string

Response

{
  "status": "completed" // or no_response, cancelled, scheduled, error
}

4. Get Transcript of a Call

Endpoint: GET /call/transcript

Query Parameters

?event_id=string

Response

{
  "status": "completed",  // or other status codes
  "transcript": "...."
}

Status Codes

Code Examples

Python (requests)

import time
import requests

one_minute_from_now = int(time.time()) + 60
url = "https://api.redialapi.com/v1/call/schedule"
headers = {
    "Authorization": "Bearer YOUR_REDIAL_API_KEY",
    "Content-Type": "application/json"
}
data = {
    "who_to_call": "+1234567890",
    "when": one_minute_from_now,
    "model": "gpt-4o-realtime-preview",
    "instructions": "Find the earliest availability."
}

response = requests.post(url, headers=headers, json=data)
print(response.json())

cURL

curl -X POST https://api.redialapi.com/v1/call/schedule \
  -H "Authorization: Bearer YOUR_REDIAL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
        "who_to_call": "+1234567890",
        "when": 1714070400,
        "model": "gpt-4o-realtime-preview",
        "instructions": "Find the earliest availability.",
        "custom_llm_config": {
          "voice": "coral",
          "turn_detection": {
            "type": "server_vad",
            "threshold": 0.5,
            "prefix_padding_ms": 250,
            "silence_duration_ms": 300
          }
        }
      }'

JavaScript (fetch)

const oneMinuteFromNow = Math.floor(Date.now() / 1000) + 60;

fetch("https://api.redialapi.com/v1/call/schedule", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_REDIAL_API_KEY",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    who_to_call: "+1234567890",
    when: oneMinuteFromNow,
    model: "gpt-4o-realtime-preview",
    instructions: "Find the earliest availability."
  })
})
.then(res => res.json())
.then(console.log);