> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://respan.ai/docs/apis/behaviors/update-custom-behavior/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://respan.ai/_mcp/server.

# Update a custom behavior

PATCH https://api.respan.ai/api/pulses/behaviors/custom/{id}/
Content-Type: application/json

Changes a custom behavior's name, definition or polarity. A new definition reaches new spans within about a minute; past spans are not rescored.

Reference: https://respan.ai/docs/apis/behaviors/update-custom-behavior

## Authentication

- `Authorization` header (bearer token, required) — Use your Respan API key for Respan API authentication. Enter only the Respan API key value; clients send Authorization: Bearer \<RESPAN\_API\_KEY>. For /api/responses, provider credentials such as Perplexity, OpenAI, or Azure OpenAI go in Settings -> Providers or respan\_params.credential\_override in the request body, not in this authentication field.

## Request

### Path parameters

- `id` (string, required) — Custom behavior ID.

### Body (application/json)

This endpoint expects a CustomBehaviorUpdateRequest.

- `description` (string, optional) — New definition. New spans are scored against it within about a minute. Past spans are not rescored.
- `name` (string, optional, nullable) — New display name. Blank or `null` clears it.
- `polarity` (enum, optional) — Whether the behavior firing is good or bad: `negative` (an Issue), `positive` (a Win) or `neutral` (Info). Display metadata only; it does not change how spans are scored.
  - Allowed values: `negative`, `positive`, `neutral`

## Response

### 200

The updated behavior, without tags.

- `id` (string, required) — Custom behavior ID. It is also the behavior's key in analytics, filters and span verdicts.
- `name` (string, required, nullable) — Display name. Optional and not unique; behaviors are identified by `id`.
- `description` (string, required) — The plain-language definition span-01 scores each span against. Say what counts and what doesn't. At least 3 characters after trimming.
- `polarity` (enum, required) — Whether the behavior firing is good or bad: `negative` (an Issue), `positive` (a Win) or `neutral` (Info). Display metadata only; it does not change how spans are scored.
  - Allowed values: `negative`, `positive`, `neutral`
- `created_at` (datetime, required)
- `updated_at` (datetime, required)

## Errors

### 400 Bad Request Error

Validation failed. The body maps each invalid field to its errors.

- `map from string to list of string`

### 403 Forbidden Error

Forbidden: the API key is missing, invalid or expired; the key doesn't grant `custom_behaviors:update` (Write access does); behaviors are turned off for the organization.

- `detail` (string, required)

### 404 Not Found Error

No custom behavior with this ID in your organization.

- `detail` (string, required)

### 429 Too Many Requests Error

Rate limited. This endpoint allows 30 requests per minute per organization.

- `detail` (string, required)

## Examples

**Request**

```json
{
  "polarity": "negative"
}
```

**Response**

```json
{
  "id": "6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93",
  "name": "Refund promise",
  "description": "The assistant promises a refund, credit, or compensation that the policy in the system prompt does not allow.",
  "polarity": "negative",
  "created_at": "2026-09-28T17:41:09.512340Z",
  "updated_at": "2026-09-28T17:41:09.512340Z"
}
```

**SDK Code**

```python Behaviors_updateCustomBehavior_example
import requests

url = "https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/"

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

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

print(response.json())
```

```javascript Behaviors_updateCustomBehavior_example
const url = 'https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/';
const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <respanApiKey>', 'Content-Type': 'application/json'},
  body: '{"polarity":"negative"}'
};

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

```go Behaviors_updateCustomBehavior_example
package main

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

func main() {

	url := "https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/"

	payload := strings.NewReader("{\n  \"polarity\": \"negative\"\n}")

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

	req.Header.Add("Authorization", "Bearer <respanApiKey>")
	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 Behaviors_updateCustomBehavior_example
require 'uri'
require 'net/http'

url = URI("https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/")

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

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

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

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

HttpResponse<String> response = Unirest.patch("https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/")
  .header("Authorization", "Bearer <respanApiKey>")
  .header("Content-Type", "application/json")
  .body("{\n  \"polarity\": \"negative\"\n}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('PATCH', 'https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/', [
  'body' => '{
  "polarity": "negative"
}',
  'headers' => [
    'Authorization' => 'Bearer <respanApiKey>',
    'Content-Type' => 'application/json',
  ],
]);

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

```csharp Behaviors_updateCustomBehavior_example
using RestSharp;

var client = new RestClient("https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/");
var request = new RestRequest(Method.PATCH);
request.AddHeader("Authorization", "Bearer <respanApiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"polarity\": \"negative\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Behaviors_updateCustomBehavior_example
import Foundation

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

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

let request = NSMutableURLRequest(url: NSURL(string: "https://api.respan.ai/api/pulses/behaviors/custom/6f1c2a9e-3b7d-4c55-9a0e-2d8f4b1c7e93/")! 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()
```