> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.getunleash.io/api/create-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] Create a context field

POST https://app.unleash-instance.example.com/api/admin/projects/{projectId}/context
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 creation of [custom context fields](https://docs.getunleash.io/concepts/unleash-context#custom-context-fields)

Reference: https://docs.getunleash.io/api/create-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)

### Body (application/json)

This endpoint expects a createContextFieldSchema.

- `name` (string, required) — The name of the context field.
- `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

### 201

The resource was successfully created.

- `name` (string, required) — The name of the context field
- `description` (string, optional, nullable) — The description of the context field.
- `stickiness` (boolean, optional) — Does this context field support being used for [stickiness](https://docs.getunleash.io/concepts/stickiness) calculations
- `sortOrder` (integer, optional) — Used when sorting a list of context fields. Is also used as a tiebreaker if a list of context fields is sorted alphabetically.
- `createdAt` (string, optional, nullable) — When this context field was created
- `usedInFeatures` (integer, optional, nullable) — Number of projects where this context field is used in
- `usedInProjects` (integer, optional, nullable) — Number of projects where this context field is used in
- `legalValues` (list of legalValueSchema, optional) — Allowed values for this context field schema. Can be used to narrow down accepted input
- `project` (string, optional) — The project this context field belongs to (if it is project-specific)

## 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
{
  "name": "subscriptionTier"
}
```

**Response**

```json
{
  "name": "userId",
  "description": "Used to uniquely identify users",
  "stickiness": true,
  "sortOrder": 900,
  "createdAt": "2023-06-29T10:19:00.000Z",
  "usedInFeatures": 3,
  "usedInProjects": 2,
  "legalValues": [
    {
      "value": "#c154c1",
      "description": "Deep fuchsia"
    }
  ],
  "project": "my-project"
}
```

**SDK Code**

```python
import requests

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

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

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

print(response.json())
```

```javascript
const url = 'https://app.unleash-instance.example.com/api/admin/projects/projectId/context';
const options = {
  method: 'POST',
  headers: {Authorization: '<apiKey>', 'Content-Type': 'application/json'},
  body: '{"name":"subscriptionTier"}'
};

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"

	payload := strings.NewReader("{\n  \"name\": \"subscriptionTier\"\n}")

	req, _ := http.NewRequest("POST", 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")

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

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

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

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://app.unleash-instance.example.com/api/admin/projects/projectId/context', [
  'body' => '{
  "name": "subscriptionTier"
}',
  '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");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"name\": \"subscriptionTier\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "<apiKey>",
  "Content-Type": "application/json"
]
let parameters = ["name": "subscriptionTier"] 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")! 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()
```