> 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.

# Create a webhook

POST https://api.smallest.ai/atoms/v1/webhook
Content-Type: application/json

Create a new webhook with subscriptions for specific agents and events.

**400 is also returned when the endpoint URL is already registered:**
`"A webhook with this URL has already been registered"`


Reference: https://docs.smallest.ai/api-reference/voice-agents/webhooks/create

## 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

### Body (application/json)

This endpoint expects an object.

- `endpoint` (string, required) — The webhook endpoint URL
- `description` (string, required) — The description of the webhook
- `events` (list of WebhookPostRequestBodyContentApplicationJsonSchemaEventsItems, required) — Array of events to subscribe to

## Response

### 201

Webhook created successfully

- `status` (boolean, optional)
- `data` (string, optional) — The ID of the created webhook

## 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)

### 500 Internal Server Error

Internal server error

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

## Types

### WebhookPostRequestBodyContentApplicationJsonSchemaEventsItems

- `agentId` (string, required) — The ID of the agent
- `eventType` (enum, required) — The type of event to subscribe to
  - Allowed values: `pre-conversation`, `post-conversation`, `analytics-completed`

## Examples

**Request**

```json
{
  "endpoint": "https://example.com/webhook",
  "description": "Webhook for conversation events",
  "events": [
    {
      "agentId": "60d0fe4f5311236168a109ca",
      "eventType": "post-conversation"
    }
  ]
}
```

**Response**

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

**SDK Code**

```python
import requests

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

payload = {
    "endpoint": "https://example.com/webhook",
    "description": "Webhook for conversation events",
    "events": [
        {
            "agentId": "60d0fe4f5311236168a109ca",
            "eventType": "post-conversation"
        }
    ]
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.json())
```

```javascript
const url = 'https://api.smallest.ai/atoms/v1/webhook';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"endpoint":"https://example.com/webhook","description":"Webhook for conversation events","events":[{"agentId":"60d0fe4f5311236168a109ca","eventType":"post-conversation"}]}'
};

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/webhook"

	payload := strings.NewReader("{\n  \"endpoint\": \"https://example.com/webhook\",\n  \"description\": \"Webhook for conversation events\",\n  \"events\": [\n    {\n      \"agentId\": \"60d0fe4f5311236168a109ca\",\n      \"eventType\": \"post-conversation\"\n    }\n  ]\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.smallest.ai/atoms/v1/webhook")

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  \"endpoint\": \"https://example.com/webhook\",\n  \"description\": \"Webhook for conversation events\",\n  \"events\": [\n    {\n      \"agentId\": \"60d0fe4f5311236168a109ca\",\n      \"eventType\": \"post-conversation\"\n    }\n  ]\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.smallest.ai/atoms/v1/webhook")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"endpoint\": \"https://example.com/webhook\",\n  \"description\": \"Webhook for conversation events\",\n  \"events\": [\n    {\n      \"agentId\": \"60d0fe4f5311236168a109ca\",\n      \"eventType\": \"post-conversation\"\n    }\n  ]\n}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.smallest.ai/atoms/v1/webhook', [
  'body' => '{
  "endpoint": "https://example.com/webhook",
  "description": "Webhook for conversation events",
  "events": [
    {
      "agentId": "60d0fe4f5311236168a109ca",
      "eventType": "post-conversation"
    }
  ]
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

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

```csharp
using RestSharp;

var client = new RestClient("https://api.smallest.ai/atoms/v1/webhook");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"endpoint\": \"https://example.com/webhook\",\n  \"description\": \"Webhook for conversation events\",\n  \"events\": [\n    {\n      \"agentId\": \"60d0fe4f5311236168a109ca\",\n      \"eventType\": \"post-conversation\"\n    }\n  ]\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [
  "endpoint": "https://example.com/webhook",
  "description": "Webhook for conversation events",
  "events": [
    [
      "agentId": "60d0fe4f5311236168a109ca",
      "eventType": "post-conversation"
    ]
  ]
] as [String : Any]

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

let request = NSMutableURLRequest(url: NSURL(string: "https://api.smallest.ai/atoms/v1/webhook")! 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()
```