> 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 a tool

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

Update a tool's definition. Propagates live to every agent that references
this tool (their config cache is busted on update).


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

## 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

- `toolId` (string, required) — The tool id, format `tool_<24 lowercase alphanumerics>`.

### Body (application/json)

- `definition` (object, required) — The tool body — the same shape used inside an agent's `tools[]` (discriminated on `type`). `api_call` is the most common; `client_tool` and the built-in types are also valid.
  - `type` (enum, required) — The registry tool type.
    - Allowed values: `api_call`, `client_tool`
  - `name` (string, required) — Unique name for the tool (no spaces)
  - `description` (string, required) — What the tool does — the agent reads this to decide when to call it
  - `enabled` (boolean, optional, default: true) — Whether the tool is enabled
  - `url` (string, optional) — Required for api_call type. The URL to make the HTTP request to.
  - `method` (enum, optional) — Required for api_call type. HTTP method to use.
    - Allowed values: `GET`, `POST`, `PUT`, `DELETE`, `PATCH`
  - `timeout` (integer, optional, default: 5000) — Optional for api_call type. Request timeout in milliseconds (1000–30000).
  - `headers` (map from string to string, optional) — Optional for api_call type. Static HTTP headers as a key/value map.
  - `headersArray` (list of object, optional) — Optional for api_call type. Headers as an array of key/value objects (alternative to `headers` map).
    - `key` (string, required)
    - `value` (string, required)
  - `queryParams` (list of object, optional) — Optional for api\_call type. Query parameters to include in the request URL. Values support variable templating like `{{order_id}}`.
    - `key` (string, required)
    - `value` (string, required)
  - `requestBody` (string, optional) — Optional for api_call type. Raw request body as a JSON string. Supports variable templating.
  - `llmParameters` (list of object, optional) — Optional for api_call type. Parameters the LLM can supply dynamically at runtime.
    - `name` (string, required) — Parameter name
    - `description` (string, required) — What the parameter represents
    - `type` (enum, required)
      - Allowed values: `text`, `number`, `boolean`, `enum`
    - `values` (list of string, optional) — Required when type is `enum`. Allowed values.
    - `required` (boolean, optional, default: false)
  - `responseVariables` (list of object, optional, default: []) — Optional for api_call type. Variables to extract from the API response into the agent's variable store.
    - `variableName` (string, required) — Name to store the extracted value under
    - `jsonPath` (string, required) — JSON path to extract the value from the response
  - `auth` (object, optional) — Optional for `api_call` type. Authentication for the outbound request. Credentials are referenced **by secret name** (from the org Secrets vault, see `POST /secret`), never inline. At call time the platform decrypts the secret, injects it into the request, and strips the `auth` block before the config reaches the runtime, cache, or webhooks. `token`, `value`, and `password` below are secret names, not literal values.
    - `type` (enum, required) — Auth scheme. `bearer` sends `Authorization: Bearer <secret>`; `api_key` sends the secret in a header or query param you name; `basic` sends `Authorization: Basic <base64(username:secret)>`.
      - Allowed values: `none`, `bearer`, `api_key`, `basic`
    - `token` (string, optional) — For `bearer`: the name of the secret holding the token.
    - `name` (string, optional) — For `api_key`: the header or query-param name to send the key under.
    - `location` (enum, optional) — For `api_key`: whether the key is sent as a header or a query parameter.
      - Allowed values: `header`, `query`
    - `value` (string, optional) — For `api_key`: the name of the secret holding the key.
    - `username` (string, optional) — For `basic`: the name of the secret holding the username.
    - `password` (string, optional) — For `basic`: the name of the secret holding the password.
  - `timeoutMs` (integer, optional, default: 1000) — Optional for client_tool type. How long the agent waits for `function_call.result` before recovering verbally.
  - `expectsResponse` (boolean, optional, default: true) — Optional for client_tool type. When false, fire-and-forget — the app acts on the event and the agent does not wait for a result.
  - `fillerPhrases` (list of string, optional, default: []) — Optional for client_tool type. Phrases spoken while the tool runs so the pause is not silent.

## Response

### 200

Tool updated.

- `status` (boolean, optional)
- `data` (object, optional) — A tool in the org-level Tools library. Referenced from agents by `toolId` (see `toolRefs` on the agent config). Editing a library tool propagates to every agent that references it.
  - `_id` (string, optional) — MongoDB id.
  - `toolId` (string, optional) — Stable public id, format `tool_<24 lowercase alphanumerics>`. This is what agents reference.
  - `organizationId` (string, optional)
  - `type` (string, optional) — The tool type (mirrors `definition.type`).
  - `definition` (object, optional) — A reusable tool definition for the org Tools registry. Only two types are registry tools: `api_call` (calls your API) and `client_tool` (runs in your app over the websocket). The built-in/system tools — `transfer_call`, `end_call`, `knowledge_base_search`, and the like — are configured per-agent in the agent's Tools tab, not created here.
    - `type` (enum, required) — The registry tool type.
      - Allowed values: `api_call`, `client_tool`
    - `name` (string, required) — Unique name for the tool (no spaces)
    - `description` (string, required) — What the tool does — the agent reads this to decide when to call it
    - `enabled` (boolean, optional, default: true) — Whether the tool is enabled
    - `url` (string, optional) — Required for api_call type. The URL to make the HTTP request to.
    - `method` (enum, optional) — Required for api_call type. HTTP method to use.
      - Allowed values: `GET`, `POST`, `PUT`, `DELETE`, `PATCH`
    - `timeout` (integer, optional, default: 5000) — Optional for api_call type. Request timeout in milliseconds (1000–30000).
    - `headers` (map from string to string, optional) — Optional for api_call type. Static HTTP headers as a key/value map.
    - `headersArray` (list of object, optional) — Optional for api_call type. Headers as an array of key/value objects (alternative to `headers` map).
      - `key` (string, required)
      - `value` (string, required)
    - `queryParams` (list of object, optional) — Optional for api\_call type. Query parameters to include in the request URL. Values support variable templating like `{{order_id}}`.
      - `key` (string, required)
      - `value` (string, required)
    - `requestBody` (string, optional) — Optional for api_call type. Raw request body as a JSON string. Supports variable templating.
    - `llmParameters` (list of object, optional) — Optional for api_call type. Parameters the LLM can supply dynamically at runtime.
      - `name` (string, required) — Parameter name
      - `description` (string, required) — What the parameter represents
      - `type` (enum, required)
        - Allowed values: `text`, `number`, `boolean`, `enum`
      - `values` (list of string, optional) — Required when type is `enum`. Allowed values.
      - `required` (boolean, optional, default: false)
    - `responseVariables` (list of object, optional, default: []) — Optional for api_call type. Variables to extract from the API response into the agent's variable store.
      - `variableName` (string, required) — Name to store the extracted value under
      - `jsonPath` (string, required) — JSON path to extract the value from the response
    - `auth` (object, optional) — Optional for `api_call` type. Authentication for the outbound request. Credentials are referenced **by secret name** (from the org Secrets vault, see `POST /secret`), never inline. At call time the platform decrypts the secret, injects it into the request, and strips the `auth` block before the config reaches the runtime, cache, or webhooks. `token`, `value`, and `password` below are secret names, not literal values.
      - `type` (enum, required) — Auth scheme. `bearer` sends `Authorization: Bearer <secret>`; `api_key` sends the secret in a header or query param you name; `basic` sends `Authorization: Basic <base64(username:secret)>`.
        - Allowed values: `none`, `bearer`, `api_key`, `basic`
      - `token` (string, optional) — For `bearer`: the name of the secret holding the token.
      - `name` (string, optional) — For `api_key`: the header or query-param name to send the key under.
      - `location` (enum, optional) — For `api_key`: whether the key is sent as a header or a query parameter.
        - Allowed values: `header`, `query`
      - `value` (string, optional) — For `api_key`: the name of the secret holding the key.
      - `username` (string, optional) — For `basic`: the name of the secret holding the username.
      - `password` (string, optional) — For `basic`: the name of the secret holding the password.
    - `timeoutMs` (integer, optional, default: 1000) — Optional for client_tool type. How long the agent waits for `function_call.result` before recovering verbally.
    - `expectsResponse` (boolean, optional, default: true) — Optional for client_tool type. When false, fire-and-forget — the app acts on the event and the agent does not wait for a result.
    - `fillerPhrases` (list of string, optional, default: []) — Optional for client_tool type. Phrases spoken while the tool runs so the pause is not silent.
  - `createdAt` (datetime, optional)
  - `updatedAt` (datetime, optional)

## Examples

**Request**

```json
{
  "definition": {
    "type": "api_call",
    "name": "get_order_status",
    "description": "Look up a customer's order by id and read back its status."
  }
}
```

**Response**

```json
{
  "status": true,
  "data": {
    "_id": "6a86c89eb3073ea15c328ce0",
    "toolId": "tool_ab12cd34ef56gh78ij90kl12",
    "organizationId": "6a5f9c9fcf10167aad404c40",
    "type": "api_call",
    "definition": {
      "type": "api_call",
      "name": "get_order_status",
      "description": "Look up a customer's order by id and read back its status.",
      "enabled": true,
      "url": "https://api.example.com/orders",
      "method": "GET",
      "timeout": 5000,
      "headers": {
        "Authorization": "Bearer TOKEN",
        "Content-Type": "application/json"
      },
      "headersArray": [
        {
          "key": "Authorization",
          "value": "Bearer TOKEN"
        }
      ],
      "queryParams": [
        {
          "key": "id",
          "value": "{{order_id}}"
        }
      ],
      "requestBody": "{\"customer_id\": \"{{customer_id}}\"}",
      "llmParameters": [
        {
          "name": "string",
          "description": "string",
          "type": "text",
          "values": [
            "string"
          ],
          "required": false
        }
      ],
      "responseVariables": [
        {
          "variableName": "orderStatus",
          "jsonPath": "$.data.status"
        }
      ],
      "auth": {
        "type": "none",
        "token": "ORDER_API_TOKEN",
        "name": "X-API-Key",
        "location": "header",
        "value": "SEARCH_API_KEY",
        "username": "string",
        "password": "string"
      },
      "timeoutMs": 1000,
      "expectsResponse": true,
      "fillerPhrases": [
        "Let me check that for you",
        "One moment please"
      ]
    },
    "createdAt": "2024-01-15T09:30:00Z",
    "updatedAt": "2024-01-15T09:30:00Z"
  }
}
```

**SDK Code**

```python
import requests

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

payload = { "definition": {
        "type": "api_call",
        "name": "get_order_status",
        "description": "Look up a customer's order by id and read back its status."
    } }
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/tool/toolId';
const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"definition":{"type":"api_call","name":"get_order_status","description":"Look up a customer\'s order by id and read back its status."}}'
};

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/tool/toolId"

	payload := strings.NewReader("{\n  \"definition\": {\n    \"type\": \"api_call\",\n    \"name\": \"get_order_status\",\n    \"description\": \"Look up a customer's order by id and read back its status.\"\n  }\n}")

	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/tool/toolId")

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 = "{\n  \"definition\": {\n    \"type\": \"api_call\",\n    \"name\": \"get_order_status\",\n    \"description\": \"Look up a customer's order by id and read back its status.\"\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.patch("https://api.smallest.ai/atoms/v1/tool/toolId")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"definition\": {\n    \"type\": \"api_call\",\n    \"name\": \"get_order_status\",\n    \"description\": \"Look up a customer's order by id and read back its status.\"\n  }\n}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('PATCH', 'https://api.smallest.ai/atoms/v1/tool/toolId', [
  'body' => '{
  "definition": {
    "type": "api_call",
    "name": "get_order_status",
    "description": "Look up a customer\'s order by id and read back its status."
  }
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

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

```csharp
using RestSharp;

var client = new RestClient("https://api.smallest.ai/atoms/v1/tool/toolId");
var request = new RestRequest(Method.PATCH);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"definition\": {\n    \"type\": \"api_call\",\n    \"name\": \"get_order_status\",\n    \"description\": \"Look up a customer's order by id and read back its status.\"\n  }\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = ["definition": [
    "type": "api_call",
    "name": "get_order_status",
    "description": "Look up a customer's order by id and read back its status."
  ]] as [String : Any]

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

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