> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 (current TTS) and Pulse (current
> STT). Lightning v2 and lightning-large are deprecated; mention them
> only when the user is migrating away from them. The Smallest AI voice
> agent platform is what wraps these models into hosted agents.

# Update an outbound SIP trunk

PATCH https://api.smallest.ai/atoms/v1/sip-trunk/outbound/{trunkId}
Content-Type: application/json

Partial update; `address` and `transport` cannot be changed (delete and recreate
instead). Removing a caller ID still used by a live campaign, as an agent's
transfer source, or attached as an agent's caller ID returns `409` naming what
uses it. Updating `cpsLimit` applies to every trunk on the same carrier address.


Reference: https://docs.smallest.ai/api-reference/voice-agents/sip-trunks/update-outbound

## Authentication

- `Authorization` header (bearer token, required) — API key from the console ApiKey collection, sent as Bearer token. Also accepts session cookies for browser-based auth.

## Request

### Path parameters

- `trunkId` (string, required)

### Body (application/json)

This endpoint expects an object.

- `name` (string, optional)
- `numbers` (list of string, optional) — Replaces the caller-ID list. E.164 with leading `+`.
- `mediaEncryption` (enum, optional)
  - Allowed values: `disable`, `allow`, `require`
- `destinationCountry` (string, optional)
- `cpsLimit` (integer, optional)
- `authUsername` (string, optional)
- `authPassword` (string, optional)

## Response

### 200

Updated trunk

- `status` (boolean, optional)
- `data` (SipOutboundTrunk, optional)

## Errors

### 404 Not Found Error

SIP trunk not found

- `any`

### 409 Conflict Error

A caller ID being removed is still in use (live campaign, transfer source, or attached as an agent caller ID), or a number being added is already a caller ID on another trunk

- `any`

## Types

### SipOutboundTrunk

- `_id` (string, optional)
- `livekitTrunkId` (string, optional)
- `name` (string, optional)
- `address` (string, optional) — The carrier termination host
- `transport` (enum, optional)
  - Allowed values: `auto`, `udp`, `tcp`, `tls`
- `numbers` (list of string, optional) — Caller IDs this trunk may present
- `mediaEncryption` (enum, optional)
  - Allowed values: `disable`, `allow`, `require`
- `cpsLimit` (integer, optional)
- `authUsername` (string, optional)
- `isActive` (boolean, optional)
- `createdAt` (datetime, optional)
- `updatedAt` (datetime, optional)

## Examples

**Request**

```json
{}
```

**Response**

```json
{
  "status": true,
  "data": {
    "_id": "string",
    "livekitTrunkId": "string",
    "name": "string",
    "address": "string",
    "transport": "auto",
    "numbers": [
      "string"
    ],
    "mediaEncryption": "disable",
    "cpsLimit": 1,
    "authUsername": "string",
    "isActive": true,
    "createdAt": "2024-01-15T09:30:00Z",
    "updatedAt": "2024-01-15T09:30:00Z"
  }
}
```

**SDK Code**

```python
import requests

url = "https://api.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId"

payload = {}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.json())
```

```javascript
const url = 'https://api.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId';
const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

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

func main() {

	url := "https://api.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId"

	payload := strings.NewReader("{}")

	req, _ := http.NewRequest("PATCH", 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.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId")

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

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{}"

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.patch("https://api.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('PATCH', 'https://api.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId', [
  'body' => '{}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId");
var request = new RestRequest(Method.PATCH);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [] as [String : Any]

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

let request = NSMutableURLRequest(url: NSURL(string: "https://api.smallest.ai/atoms/v1/sip-trunk/outbound/trunkId")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "PATCH"
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()
```