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

# Register client usage metrics

POST https://app.unleash-instance.example.com/api/client/metrics
Content-Type: application/json

Registers usage metrics. Stores information about how many times each flag was evaluated to enabled and disabled within a time frame. If provided, this operation will also store data on how many times each feature flag's variants were displayed to the end user.

Reference: https://docs.getunleash.io/api/register-client-metrics

## 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

### Body (application/json)

This endpoint expects a clientMetricsSchema.

- `appName` (string, required) — The name of the application that is evaluating toggles
- `instanceId` (string, optional) — A [(somewhat) unique identifier](https://docs.getunleash.io/sdks/node#advanced-usage) for the application
- `sdkVersion` (string, optional) — An SDK version identifier. Usually formatted as "unleash-client-\<language>:\<version>"
- `platformName` (string, optional) — The platform the application is running on. For languages that compile to binaries, this can be omitted
- `platformVersion` (string, optional) — The version of the platform the application is running on. Languages that compile to binaries, this is expected to be the compiler version used to assemble the binary.
- `yggdrasilVersion` (string, optional) — The semantic version of the Yggdrasil engine used by the client. If the client is using a native engine this can be omitted.
- `specVersion` (string, optional) — The version of the Unleash client specification the client supports
- `sdkFlavor` (string, optional) — The identifier of an integration built on top of an Unleash SDK (e.g. an OpenFeature provider). Sent so adoption of the integration can be tracked alongside sdkVersion.
- `sdkFlavorVersion` (string, optional) — The version of the integration identified by sdk flavor, that has been built on top of an Unleash SDK
- `bucket` (ClientMetricsSchemaBucket, optional, nullable) — Holds all metrics gathered over a window of time. Typically 1 hour wide. May be omitted or null when the request only carries impact metrics.

## Response

### 202

This response has no body.

## Errors

### 400 Bad Request Error

The request data does not match what we expect.

- `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

### ClientMetricsSchemaBucket

Holds all metrics gathered over a window of time. Typically 1 hour wide. May be omitted or null when the request only carries impact metrics.

- `start` (dateSchema, required) — The start of the time window these metrics are valid for. The window is usually 1 hour wide
- `stop` (dateSchema, required) — The end of the time window these metrics are valid for. The window is 1 hour wide
- `toggles` (map from string to ClientMetricsSchemaBucketToggles, required) — an object containing feature names with yes/no plus variant usage

### dateSchema

A representation of a date. Either as a date-time string or as a UNIX timestamp.

### ClientMetricsSchemaBucketToggles

- `yes` (double, optional) — How many times the toggle evaluated to true
- `no` (integer, optional) — How many times the toggle evaluated to false
- `variants` (map from string to integer, optional, nullable) — An object describing how many times each variant was returned. Variant names are used as properties, and the number of times they were exposed is the corresponding value (i.e. `{ [variantName]: number }`).

## Examples

**Request**

```json
{
  "appName": "insurance-selector"
}
```

**Response**

```json
{}
```

**SDK Code**

```python
import requests

url = "https://app.unleash-instance.example.com/api/client/metrics"

payload = { "appName": "insurance-selector" }
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/client/metrics';
const options = {
  method: 'POST',
  headers: {Authorization: '<apiKey>', 'Content-Type': 'application/json'},
  body: '{"appName":"insurance-selector"}'
};

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/client/metrics"

	payload := strings.NewReader("{\n  \"appName\": \"insurance-selector\"\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/client/metrics")

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  \"appName\": \"insurance-selector\"\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/client/metrics")
  .header("Authorization", "<apiKey>")
  .header("Content-Type", "application/json")
  .body("{\n  \"appName\": \"insurance-selector\"\n}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://app.unleash-instance.example.com/api/client/metrics', [
  'body' => '{
  "appName": "insurance-selector"
}',
  'headers' => [
    'Authorization' => '<apiKey>',
    'Content-Type' => 'application/json',
  ],
]);

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

```csharp
using RestSharp;

var client = new RestClient("https://app.unleash-instance.example.com/api/client/metrics");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"appName\": \"insurance-selector\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

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

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

let request = NSMutableURLRequest(url: NSURL(string: "https://app.unleash-instance.example.com/api/client/metrics")! 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()
```