> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.getunleash.io/api/update-context-field-for-project/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.getunleash.io/_mcp/server.

# [BETA] Update an existing context field

PUT https://app.unleash-instance.example.com/api/admin/projects/{projectId}/context/{contextField}
Content-Type: application/json

**[BETA]** This API is in beta state, which means it may change or be removed in the future.

Endpoint that allows updating a custom context field. Used to toggle stickiness and add/remove legal values for this context field

Reference: https://docs.getunleash.io/api/update-context-field-for-project

## Authentication

- `Authorization` header (required) — API key needed to access this API
- `Authorization` header (bearer token, required) — API key needed to access this API, in Bearer token format

## Request

### Path parameters

- `projectId` (string, required)
- `contextField` (string, required)

### Body (application/json)

This endpoint expects an updateContextFieldSchema.

- `description` (string, optional) — A description of the context field
- `stickiness` (boolean, optional) — `true` if this field should be available for use with [custom stickiness](https://docs.getunleash.io/concepts/stickiness#custom-stickiness), otherwise `false`
- `sortOrder` (integer, optional) — How this context field should be sorted if no other sort order is selected
- `legalValues` (list of legalValueSchema, optional) — A list of allowed values for this context field
- `project` (string, optional) — The project this context field belongs to (if it is project-specific)

## Response

### 200

This response has no body.

## Types

### legalValueSchema

Describes a legal value. Typically used to limit possible values for contextFields or strategy properties

- `value` (string, required) — The valid value
- `description` (string, optional) — Describes this specific legal value

## Examples

**Request**

```json
{}
```

**Response**

```json
{}
```

**SDK Code**

```python
import requests

url = "https://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField"

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

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

print(response.json())
```

```javascript
const url = 'https://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField';
const options = {
  method: 'PUT',
  headers: {Authorization: '<apiKey>', '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://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField"

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

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

	req.Header.Add("Authorization", "<apiKey>")
	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://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField")

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

request = Net::HTTP::Put.new(url)
request["Authorization"] = '<apiKey>'
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.put("https://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField")
  .header("Authorization", "<apiKey>")
  .header("Content-Type", "application/json")
  .body("{}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('PUT', 'https://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField', [
  'body' => '{}',
  'headers' => [
    'Authorization' => '<apiKey>',
    'Content-Type' => 'application/json',
  ],
]);

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

```csharp
using RestSharp;

var client = new RestClient("https://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField");
var request = new RestRequest(Method.PUT);
request.AddHeader("Authorization", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

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

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

let request = NSMutableURLRequest(url: NSURL(string: "https://app.unleash-instance.example.com/api/admin/projects/projectId/context/contextField")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "PUT"
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()
```