> 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 agent metadata

PATCH https://api.smallest.ai/atoms/v1/agent/{id}
Content-Type: application/json

Update agent fields. Behavior depends on whether the agent has versioning enabled:

**Versioned agents** (have an active published version): only metadata fields are accepted:
`name`, `description`, `avatarUrl`, `telephonyProductId`, `allowInboundCall`, `visibleToEveryone`.
Submitting any config-level field returns 400 with the message
`"Config changes must be made through a branch draft. Use PUT /agent/:id/branches/:branchId/draft."`.
Use the branches flow. See `GET /agent/{id}/branches` to list branches and `PUT /agent/{id}/branches/{branchId}/draft` to open or edit a draft on a branch.

**Non-versioned agents** (no active version): all configuration fields are accepted,
the same full set as `POST /agent`.

**400 is also returned when a cross-field constraint is violated** (for example, `north_indic` language requires `transcriberType: pulse`).

**403** is returned when selecting a gated model (`gpt-5.2`, `electron-kogta`, `electron-kogta-v2`)
without org-level access.

Reference: https://docs.smallest.ai/api-reference/voice-agents/agents/update-agent

## 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

- `id` (string, required)

### Body (application/json)

This endpoint expects an UpdateAgentRequest.

- `name` (string, optional) — Name of the agent.
- `description` (string, optional) — Description of the agent.
- `avatarUrl` (string, optional) — URL of the agent's avatar image.
- `visibleToEveryone` (boolean, optional) — Whether the agent is visible to all members of the organization.
- `transcriberType` (enum, optional) — STT engine for the agent's turn detection and transcription. `pulse-legacy` is retained for older integrations. Only accepted on non-versioned agents; versioned agents change transcriber via the branch-draft flow (`PUT /agent/{id}/branches/{branchId}/draft`).
  - Allowed values: `pulse`, `pulse-legacy`, `gpt-realtime`, `gpt-realtime-mini`
- `telephonyProductId` (list of string, optional, deprecated) — **Deprecated.** Applied as the agent's answer sources during the migration window (replace semantics; the response carries `Deprecation: true` when sent). Use `POST /agent/{agentId}/answers` instead.
- `allowInboundCall` (boolean, optional, deprecated) — **Deprecated.** `false` still works as a routing kill switch during the migration window; `true` undoes a previous `false`, otherwise no effect. Detach the number via `DELETE /agent/{agentId}/answers/{sourceId}` instead.

## Response

### 200

Agent updated successfully

- `status` (boolean, optional)
- `data` (string, optional) — The ID of the updated agent

## Errors

### 400 Bad Request Error

Invalid input

- `status` (boolean, optional)
- `errors` (list of string, optional)

### 401 Unauthorized Error

Unauthorized access

- `status` (boolean, optional)
- `errors` (list of string, optional)

### 403 Forbidden Error

Forbidden access

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

### 404 Not Found Error

Agent not found

- `any`

### 500 Internal Server Error

Internal server error

- `status` (boolean, optional)
- `errors` (list of string, optional)

## Types

### ApiResponseData

## Examples

**Request**

```json
{}
```

**Response**

```json
{
  "status": true,
  "data": "60d0fe4f5311236168a109ca"
}
```

**SDK Code**

```python
import requests

url = "https://api.smallest.ai/atoms/v1/agent/id"

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/agent/id';
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/agent/id"

	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/agent/id")

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/agent/id")
  .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/agent/id', [
  '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/agent/id");
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/agent/id")! 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()
```