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

# Adds a tag to the specified features

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

Add a tag to a list of features. Create tags if needed.

Reference: https://docs.getunleash.io/api/add-tag-to-features

## 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 tagsBulkAddSchema.

- `features` (list of string, required) — The list of features that will be affected by the tag changes.
- `tags` (updateTagsSchema, required) — The tag changes to be applied to the features.

## Response

### 200

This response has no body.

## Errors

### 401 Unauthorized Error

Authorization information is missing or invalid. Provide a valid API token as the `authorization` header, e.g. `authorization:*.*.my-admin-token`.

- `id` (string, optional) — The ID of the error instance
- `name` (string, optional) — The name of the error kind
- `message` (string, optional) — A description of what went wrong.

### 403 Forbidden Error

The provided user credentials are valid, but the user does not have the necessary permissions to perform this operation

- `id` (string, optional) — The ID of the error instance
- `name` (string, optional) — The name of the error kind
- `message` (string, optional) — A description of what went wrong.

### 404 Not Found Error

The requested resource was not found.

- `id` (string, optional) — The ID of the error instance
- `name` (string, optional) — The name of the error kind
- `message` (string, optional) — A description of what went wrong.

### 415 Unsupported Media Type Error

The operation does not support request payloads of the provided type. Please ensure that you're using one of the listed payload types and that you have specified the right content type in the "content-type" header.

- `id` (string, optional) — The ID of the error instance
- `name` (string, optional) — The name of the error kind
- `message` (string, optional) — A description of what went wrong.

## Types

### updateTagsSchema

Represents a set of changes to a feature's tags, such as adding or removing tags.

- `addedTags` (list of tagSchema, required) — Tags to add to the feature.
- `removedTags` (list of tagSchema, required) — Tags to remove from the feature.

### tagSchema

Representation of a [tag](https://docs.getunleash.io/concepts/feature-flags#tags)

- `value` (string, required) — The value of the tag.
- `type` (string, required) — The [type](https://docs.getunleash.io/concepts/feature-flags#tags) of the tag
- `color` (string, optional, nullable) — The hexadecimal color code for the tag type.

## Examples

**Request**

```json
{
  "features": [
    "string"
  ],
  "tags": {
    "addedTags": [
      {
        "value": "tag-to-add",
        "type": "simple"
      }
    ],
    "removedTags": [
      {
        "value": "tag-to-remove",
        "type": "simple"
      }
    ]
  }
}
```

**Response**

```json
{}
```

**SDK Code**

```python
import requests

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

payload = {
    "features": ["string"],
    "tags": {
        "addedTags": [
            {
                "value": "tag-to-add",
                "type": "simple"
            }
        ],
        "removedTags": [
            {
                "value": "tag-to-remove",
                "type": "simple"
            }
        ]
    }
}
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/tags';
const options = {
  method: 'PUT',
  headers: {Authorization: '<apiKey>', 'Content-Type': 'application/json'},
  body: '{"features":["string"],"tags":{"addedTags":[{"value":"tag-to-add","type":"simple"}],"removedTags":[{"value":"tag-to-remove","type":"simple"}]}}'
};

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/tags"

	payload := strings.NewReader("{\n  \"features\": [\n    \"string\"\n  ],\n  \"tags\": {\n    \"addedTags\": [\n      {\n        \"value\": \"tag-to-add\",\n        \"type\": \"simple\"\n      }\n    ],\n    \"removedTags\": [\n      {\n        \"value\": \"tag-to-remove\",\n        \"type\": \"simple\"\n      }\n    ]\n  }\n}")

	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/tags")

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 = "{\n  \"features\": [\n    \"string\"\n  ],\n  \"tags\": {\n    \"addedTags\": [\n      {\n        \"value\": \"tag-to-add\",\n        \"type\": \"simple\"\n      }\n    ],\n    \"removedTags\": [\n      {\n        \"value\": \"tag-to-remove\",\n        \"type\": \"simple\"\n      }\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.put("https://app.unleash-instance.example.com/api/admin/projects/projectId/tags")
  .header("Authorization", "<apiKey>")
  .header("Content-Type", "application/json")
  .body("{\n  \"features\": [\n    \"string\"\n  ],\n  \"tags\": {\n    \"addedTags\": [\n      {\n        \"value\": \"tag-to-add\",\n        \"type\": \"simple\"\n      }\n    ],\n    \"removedTags\": [\n      {\n        \"value\": \"tag-to-remove\",\n        \"type\": \"simple\"\n      }\n    ]\n  }\n}")
  .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/tags', [
  'body' => '{
  "features": [
    "string"
  ],
  "tags": {
    "addedTags": [
      {
        "value": "tag-to-add",
        "type": "simple"
      }
    ],
    "removedTags": [
      {
        "value": "tag-to-remove",
        "type": "simple"
      }
    ]
  }
}',
  '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/tags");
var request = new RestRequest(Method.PUT);
request.AddHeader("Authorization", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"features\": [\n    \"string\"\n  ],\n  \"tags\": {\n    \"addedTags\": [\n      {\n        \"value\": \"tag-to-add\",\n        \"type\": \"simple\"\n      }\n    ],\n    \"removedTags\": [\n      {\n        \"value\": \"tag-to-remove\",\n        \"type\": \"simple\"\n      }\n    ]\n  }\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "<apiKey>",
  "Content-Type": "application/json"
]
let parameters = [
  "features": ["string"],
  "tags": [
    "addedTags": [
      [
        "value": "tag-to-add",
        "type": "simple"
      ]
    ],
    "removedTags": [
      [
        "value": "tag-to-remove",
        "type": "simple"
      ]
    ]
  ]
] 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/tags")! 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()
```