> For a complete page index, fetch https://docs.synthflow.ai/llms.txt. For full documentation content, fetch https://docs.synthflow.ai/llms-full.txt.

# Start an outbound chat conversation

POST https://api.synthflow.ai/v2/chat/outbound
Content-Type: application/json

Create a new outbound WhatsApp or SMS conversation for a chat agent.

Reference: https://docs.synthflow.ai/api-reference/platform-api/chat/create-outbound-chat

## Authentication

- `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer <token>`, where token is your auth token.

## Servers

- `https://api.synthflow.ai/v2` (Global, default)
- `https://api.us.synthflow.ai/v2` (United States)
- `https://api.eu.synthflow.ai/v2` (European Union)

## Request

### Body (application/json)

This endpoint expects an OutboundChatRequest.

- `agent_id` (string, required) — The ID of the chat agent that will handle the conversation.
- `channel` (enum, required) — Outbound messaging channel.
  - Allowed values: `sms`, `whatsapp`
- `to_number` (string, required) — Recipient phone number in E.164 format.
- `from_number` (string, required) — Twilio sender phone number in E.164 format.
- `initial_message` (string, optional) — Freeform opening message. For WhatsApp, this is only valid within the 24-hour customer service window.
- `template` (OutboundChatTemplate, optional) — Approved Twilio Content Template for WhatsApp outbound messages. Required outside the 24-hour customer service window, optional within it.
- `custom_variables` (map from string to any, optional) — Custom prompt variables to inject into the agent configuration for this conversation.

## Response

### 200

200

- `status` (string, required) — Whether the request was successful.
- `response` (OutboundChatResponseResponse, required)

## Errors

### 400 Bad Request Error

400

## Types

### OutboundChatTemplate

Twilio Content Template to use for outbound WhatsApp delivery.

- `content_sid` (string, required) — The SID of an approved Twilio Content Template.
- `variables` (map from string to any, optional) — Template variable substitutions keyed by placeholder number.

### OutboundChatResponseResponse

- `conversation_id` (string, required) — Unique identifier for the created conversation.

## Examples

**Request**

```json
{
  "agent_id": "2a886b7d-d52d-4f8b-8ea0-19d3edc79214",
  "channel": "whatsapp",
  "to_number": "+15559876543",
  "from_number": "+15551234567",
  "initial_message": "Hi! How can I help you today?"
}
```

**Response**

```json
{
  "status": "ok",
  "response": {
    "conversation_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
  }
}
```

**SDK Code**

```python
import requests

url = "https://api.synthflow.ai/v2/chat/outbound"

payload = {
    "agent_id": "2a886b7d-d52d-4f8b-8ea0-19d3edc79214",
    "channel": "whatsapp",
    "to_number": "+15559876543",
    "from_number": "+15551234567",
    "initial_message": "Hi! How can I help you today?"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.synthflow.ai/v2/chat/outbound"

	payload := strings.NewReader("{\n  \"agent_id\": \"2a886b7d-d52d-4f8b-8ea0-19d3edc79214\",\n  \"channel\": \"whatsapp\",\n  \"to_number\": \"+15559876543\",\n  \"from_number\": \"+15551234567\",\n  \"initial_message\": \"Hi! How can I help you today?\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.synthflow.ai/v2/chat/outbound")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"agent_id\": \"2a886b7d-d52d-4f8b-8ea0-19d3edc79214\",\n  \"channel\": \"whatsapp\",\n  \"to_number\": \"+15559876543\",\n  \"from_number\": \"+15551234567\",\n  \"initial_message\": \"Hi! How can I help you today?\"\n}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.synthflow.ai/v2/chat/outbound")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"agent_id\": \"2a886b7d-d52d-4f8b-8ea0-19d3edc79214\",\n  \"channel\": \"whatsapp\",\n  \"to_number\": \"+15559876543\",\n  \"from_number\": \"+15551234567\",\n  \"initial_message\": \"Hi! How can I help you today?\"\n}")
  .asString();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.synthflow.ai/v2/chat/outbound");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"agent_id\": \"2a886b7d-d52d-4f8b-8ea0-19d3edc79214\",\n  \"channel\": \"whatsapp\",\n  \"to_number\": \"+15559876543\",\n  \"from_number\": \"+15551234567\",\n  \"initial_message\": \"Hi! How can I help you today?\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [
  "agent_id": "2a886b7d-d52d-4f8b-8ea0-19d3edc79214",
  "channel": "whatsapp",
  "to_number": "+15559876543",
  "from_number": "+15551234567",
  "initial_message": "Hi! How can I help you today?"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.synthflow.ai/v2/chat/outbound")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```