---
title: Cancel experiment
description: Cancel an experiment, ending it without a winning variant.
breadcrumbs: Documentación > API > Cancel experiment
---

> For the complete documentation index, see [llms.txt](https://dnd37xeb23o8n.cloudfront.net/jen.gilbert/astro-base/llms.txt).

# Cancel experiment

{% callout %}
This product or feature is not supported for the following sites: app.ddog-gov.com, us2.ddog-gov.com
{% /callout %}

## v2 (latest)

| Datadog site      | API endpoint                                                                 |
| ----------------- | ---------------------------------------------------------------------------- |
| app.datadoghq.com | POST https://api.datadoghq.com/api/v2/experiments/{experiment_id}/cancel     |
| us3.datadoghq.com | POST https://api.us3.datadoghq.com/api/v2/experiments/{experiment_id}/cancel |
| us5.datadoghq.com | POST https://api.us5.datadoghq.com/api/v2/experiments/{experiment_id}/cancel |
| app.datadoghq.eu  | POST https://api.datadoghq.eu/api/v2/experiments/{experiment_id}/cancel      |
| ap1.datadoghq.com | POST https://api.ap1.datadoghq.com/api/v2/experiments/{experiment_id}/cancel |
| ap2.datadoghq.com | POST https://api.ap2.datadoghq.com/api/v2/experiments/{experiment_id}/cancel |
| uk1.datadoghq.com | POST https://api.uk1.datadoghq.com/api/v2/experiments/{experiment_id}/cancel |
| app.ddog-gov.com  | POST https://api.ddog-gov.com/api/v2/experiments/{experiment_id}/cancel      |
| us2.ddog-gov.com  | POST https://api.us2.ddog-gov.com/api/v2/experiments/{experiment_id}/cancel  |

### Overview

Cancel an experiment, ending it without a winning variant. The experiment moves to CANCELLED status, the
supplied reason is recorded in its conclusion as the decision reason, and the experiment is unlinked from the
feature flag allocations that exposed it, which stops its exposure. An experiment that has already completed
its rollout, had its code removed, or been canceled cannot be canceled again. Canceling is not reversible: an
experiment cannot be returned to a running state afterward. It is also not idempotent: canceling an
already-canceled experiment returns 409, so a retry after a timeout cannot be distinguished from a
cancellation made by someone else.

This endpoint requires the `product_analytics_experiments_write` permission.

OAuth apps require the `product_analytics_experiments_write` authorization [scope](https://dnd37xeb23o8n.cloudfront.net/jen.gilbert/astro-base/es/api/latest/scopes.md#experiments) to access this endpoint.

### Arguments

#### Path Parameters

| Field                      | Type   | Description                 |
| -------------------------- | ------ | --------------------------- |
| experiment_id [*required*] | string | The UUID of the experiment. |

### Request

#### Body Data (required)

{% tabs %}
{% tab label="Model" %}
| Parent field | Field                   | Type   | Description                                                                                                                      |
| ------------ | ----------------------- | ------ | -------------------------------------------------------------------------------------------------------------------------------- |
|              | data [*required*]       | object | Experiment cancellation resource with the experiment identifier and reason.                                                      |
| data         | attributes [*required*] | object | Reason to record when canceling the experiment.                                                                                  |
| attributes   | reason [*required*]     | string | Reason the experiment was canceled. Stored as the decision reason on the experiment conclusion. Must not be blank.               |
| data         | id                      | string | Identifier of the experiment to cancel.                                                                                          |
| data         | type [*required*]       | enum   | Cancel experiment request resource type. Allowed enum values: `cancel-experiment-request`. Default: `cancel-experiment-request`. |
{% /tab %}

{% tab label="Example" %}
```json
{
  "data": {
    "type": "cancel-experiment-request",
    "attributes": {
      "reason": "Cancel the test experiment"
    }
  }
}
```
{% /tab %}
{% /tabs %}

### Response

{% tabs %}
{% tab label="204" %}
The experiment was canceled and unlinked from its feature flag allocations.
{% /tab %}

{% tab label="400" %}
Malformed experiment ID, malformed request body, or a missing/blank reason.

{% tabs %}
{% tab label="Model" %}
API error response.

| Parent field | Field               | Type     | Description                                                                     |
| ------------ | ------------------- | -------- | ------------------------------------------------------------------------------- |
|              | errors [*required*] | [object] | A list of errors.                                                               |
| errors       | detail              | string   | A human-readable explanation specific to this occurrence of the error.          |
| errors       | meta                | object   | Non-standard meta-information about the error                                   |
| errors       | source              | object   | References to the source of the error.                                          |
| source       | header              | string   | A string indicating the name of a single request header which caused the error. |
| source       | parameter           | string   | A string indicating which URI query parameter caused the error.                 |
| source       | pointer             | string   | A JSON pointer to the value in the request document that caused the error.      |
| errors       | status              | string   | Status code of the response.                                                    |
| errors       | title               | string   | Short human-readable summary of the error.                                      |
{% /tab %}

{% tab label="Example" %}
```json
{
  "errors": [
    {
      "detail": "Missing required attribute in body",
      "meta": {},
      "source": {
        "header": "Authorization",
        "parameter": "limit",
        "pointer": "/data/attributes/title"
      },
      "status": "400",
      "title": "Bad Request"
    }
  ]
}
```
{% /tab %}
{% /tabs %}
{% /tab %}

{% tab label="401" %}
Missing or invalid authentication (dd-api-key + dd-application-key headers, or a valid user session).

{% tabs %}
{% tab label="Model" %}
API error response.

| Parent field | Field               | Type     | Description                                                                     |
| ------------ | ------------------- | -------- | ------------------------------------------------------------------------------- |
|              | errors [*required*] | [object] | A list of errors.                                                               |
| errors       | detail              | string   | A human-readable explanation specific to this occurrence of the error.          |
| errors       | meta                | object   | Non-standard meta-information about the error                                   |
| errors       | source              | object   | References to the source of the error.                                          |
| source       | header              | string   | A string indicating the name of a single request header which caused the error. |
| source       | parameter           | string   | A string indicating which URI query parameter caused the error.                 |
| source       | pointer             | string   | A JSON pointer to the value in the request document that caused the error.      |
| errors       | status              | string   | Status code of the response.                                                    |
| errors       | title               | string   | Short human-readable summary of the error.                                      |
{% /tab %}

{% tab label="Example" %}
```json
{
  "errors": [
    {
      "detail": "Missing required attribute in body",
      "meta": {},
      "source": {
        "header": "Authorization",
        "parameter": "limit",
        "pointer": "/data/attributes/title"
      },
      "status": "400",
      "title": "Bad Request"
    }
  ]
}
```
{% /tab %}
{% /tabs %}
{% /tab %}

{% tab label="403" %}
Authenticated caller lacks the product_analytics_experiments_write permission, lacks permission to edit this experiment, or lacks contribute permission on the feature flag owning its allocation.

{% tabs %}
{% tab label="Model" %}
API error response.

| Parent field | Field               | Type     | Description                                                                     |
| ------------ | ------------------- | -------- | ------------------------------------------------------------------------------- |
|              | errors [*required*] | [object] | A list of errors.                                                               |
| errors       | detail              | string   | A human-readable explanation specific to this occurrence of the error.          |
| errors       | meta                | object   | Non-standard meta-information about the error                                   |
| errors       | source              | object   | References to the source of the error.                                          |
| source       | header              | string   | A string indicating the name of a single request header which caused the error. |
| source       | parameter           | string   | A string indicating which URI query parameter caused the error.                 |
| source       | pointer             | string   | A JSON pointer to the value in the request document that caused the error.      |
| errors       | status              | string   | Status code of the response.                                                    |
| errors       | title               | string   | Short human-readable summary of the error.                                      |
{% /tab %}

{% tab label="Example" %}
```json
{
  "errors": [
    {
      "detail": "Missing required attribute in body",
      "meta": {},
      "source": {
        "header": "Authorization",
        "parameter": "limit",
        "pointer": "/data/attributes/title"
      },
      "status": "400",
      "title": "Bad Request"
    }
  ]
}
```
{% /tab %}
{% /tabs %}
{% /tab %}

{% tab label="404" %}
No experiment with this ID exists for the organization.

{% tabs %}
{% tab label="Model" %}
API error response.

| Parent field | Field               | Type     | Description                                                                     |
| ------------ | ------------------- | -------- | ------------------------------------------------------------------------------- |
|              | errors [*required*] | [object] | A list of errors.                                                               |
| errors       | detail              | string   | A human-readable explanation specific to this occurrence of the error.          |
| errors       | meta                | object   | Non-standard meta-information about the error                                   |
| errors       | source              | object   | References to the source of the error.                                          |
| source       | header              | string   | A string indicating the name of a single request header which caused the error. |
| source       | parameter           | string   | A string indicating which URI query parameter caused the error.                 |
| source       | pointer             | string   | A JSON pointer to the value in the request document that caused the error.      |
| errors       | status              | string   | Status code of the response.                                                    |
| errors       | title               | string   | Short human-readable summary of the error.                                      |
{% /tab %}

{% tab label="Example" %}
```json
{
  "errors": [
    {
      "detail": "Missing required attribute in body",
      "meta": {},
      "source": {
        "header": "Authorization",
        "parameter": "limit",
        "pointer": "/data/attributes/title"
      },
      "status": "400",
      "title": "Bad Request"
    }
  ]
}
```
{% /tab %}
{% /tabs %}
{% /tab %}

{% tab label="409" %}
The experiment cannot be canceled in its current state.

{% tabs %}
{% tab label="Model" %}
API error response.

| Parent field | Field               | Type     | Description                                                                     |
| ------------ | ------------------- | -------- | ------------------------------------------------------------------------------- |
|              | errors [*required*] | [object] | A list of errors.                                                               |
| errors       | detail              | string   | A human-readable explanation specific to this occurrence of the error.          |
| errors       | meta                | object   | Non-standard meta-information about the error                                   |
| errors       | source              | object   | References to the source of the error.                                          |
| source       | header              | string   | A string indicating the name of a single request header which caused the error. |
| source       | parameter           | string   | A string indicating which URI query parameter caused the error.                 |
| source       | pointer             | string   | A JSON pointer to the value in the request document that caused the error.      |
| errors       | status              | string   | Status code of the response.                                                    |
| errors       | title               | string   | Short human-readable summary of the error.                                      |
{% /tab %}

{% tab label="Example" %}
```json
{
  "errors": [
    {
      "detail": "Missing required attribute in body",
      "meta": {},
      "source": {
        "header": "Authorization",
        "parameter": "limit",
        "pointer": "/data/attributes/title"
      },
      "status": "400",
      "title": "Bad Request"
    }
  ]
}
```
{% /tab %}
{% /tabs %}
{% /tab %}

{% tab label="429" %}
Too many requests

{% tabs %}
{% tab label="Model" %}
API error response.

| Field               | Type     | Description       |
| ------------------- | -------- | ----------------- |
| errors [*required*] | [string] | A list of errors. |
{% /tab %}

{% tab label="Example" %}
```json
{
  "errors": [
    "Bad Request"
  ]
}
```
{% /tab %}
{% /tabs %}
{% /tab %}
{% /tabs %}

### Code Example

{% tabs %}
{% tab label="Curl" %}
```bash
# Path parameters
export experiment_id="550e8400-e29b-41d4-a716-446655440000"

# Set your Datadog site and credentials
export DD_SITE="datadoghq.com" # Or us3.datadoghq.com, us5.datadoghq.com, datadoghq.eu, ap1.datadoghq.com, ap2.datadoghq.com, uk1.datadoghq.com, ddog-gov.com, us2.ddog-gov.com
# Use a Personal Access Token or Service Access Token
export DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>"

curl -X POST "https://api.${DD_SITE}/api/v2/experiments/${experiment_id}/cancel" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer ${DD_BEARER_TOKEN}" \
-d @- << EOF
{
  "data": {
    "type": "cancel-experiment-request",
    "attributes": {
      "reason": "Cancel the test experiment"
    }
  }
}
EOF
```
{% /tab %}

{% tab label="Go" %}
```go
// Cancel experiment returns "The experiment was canceled and unlinked from its feature flag allocations." response

package main

import (
	"context"
	"fmt"
	"os"

	"github.com/DataDog/datadog-api-client-go/v2/api/datadog"
	"github.com/DataDog/datadog-api-client-go/v2/api/datadogV2"
	"github.com/google/uuid"
)

func main() {
	// there is a valid "experiment" in the system
	ExperimentDataID := uuid.MustParse(os.Getenv("EXPERIMENT_DATA_ID"))

	body := datadogV2.ExperimentsCancelExperimentV2Request{
		Data: datadogV2.ExperimentsCancelExperimentV2RequestData{
			Type: datadogV2.EXPERIMENTSCANCELEXPERIMENTV2REQUESTDATATYPE_CANCEL_EXPERIMENT_REQUEST,
			Attributes: datadogV2.ExperimentsCancelExperimentV2RequestDataAttributes{
				Reason: "Cancel the test experiment",
			},
		},
	}
	ctx := datadog.NewDefaultContext(context.Background())
	ctx = context.WithValue(ctx, datadog.ContextAccessToken, os.Getenv("DD_BEARER_TOKEN"))
	configuration := datadog.NewConfiguration()
	apiClient := datadog.NewAPIClient(configuration)
	api := datadogV2.NewExperimentsApi(apiClient)
	r, err := api.CancelExperiment(ctx, ExperimentDataID, body)

	if err != nil {
		fmt.Fprintf(os.Stderr, "Error when calling `ExperimentsApi.CancelExperiment`: %v\n", err)
		fmt.Fprintf(os.Stderr, "Full HTTP response: %v\n", r)
	}
}
```

#### Instructions

First [install the library and its dependencies](https://dnd37xeb23o8n.cloudfront.net/api/latest.md?code-lang=go) and then save the example to `main.go` and run following commands:

```bash
DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" go run "main.go"
```
{% /tab %}

{% tab label="Java" %}
```java
// Cancel experiment returns "The experiment was canceled and unlinked from its feature flag
// allocations." response

import com.datadog.api.client.ApiClient;
import com.datadog.api.client.ApiException;
import com.datadog.api.client.v2.api.ExperimentsApi;
import com.datadog.api.client.v2.model.ExperimentsCancelExperimentV2Request;
import com.datadog.api.client.v2.model.ExperimentsCancelExperimentV2RequestData;
import com.datadog.api.client.v2.model.ExperimentsCancelExperimentV2RequestDataAttributes;
import com.datadog.api.client.v2.model.ExperimentsCancelExperimentV2RequestDataType;
import java.util.UUID;

public class Example {
  public static void main(String[] args) {
    ApiClient defaultClient = ApiClient.getDefaultApiClient();
    defaultClient.setAccessToken(System.getenv("DD_BEARER_TOKEN"));
    ExperimentsApi apiInstance = new ExperimentsApi(defaultClient);

    // there is a valid "experiment" in the system
    UUID EXPERIMENT_DATA_ID = null;
    try {
      EXPERIMENT_DATA_ID = UUID.fromString(System.getenv("EXPERIMENT_DATA_ID"));
    } catch (IllegalArgumentException e) {
      System.err.println("Error parsing UUID: " + e.getMessage());
    }

    ExperimentsCancelExperimentV2Request body =
        new ExperimentsCancelExperimentV2Request()
            .data(
                new ExperimentsCancelExperimentV2RequestData()
                    .type(ExperimentsCancelExperimentV2RequestDataType.CANCEL_EXPERIMENT_REQUEST)
                    .attributes(
                        new ExperimentsCancelExperimentV2RequestDataAttributes()
                            .reason("Cancel the test experiment")));

    try {
      apiInstance.cancelExperiment(EXPERIMENT_DATA_ID, body);
    } catch (ApiException e) {
      System.err.println("Exception when calling ExperimentsApi#cancelExperiment");
      System.err.println("Status code: " + e.getCode());
      System.err.println("Reason: " + e.getResponseBody());
      System.err.println("Response headers: " + e.getResponseHeaders());
      e.printStackTrace();
    }
  }
}
```

#### Instructions

First [install the library and its dependencies](https://dnd37xeb23o8n.cloudfront.net/api/latest.md?code-lang=java) and then save the example to `Example.java` and run following commands:

```bash
DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" java "Example.java"
```
{% /tab %}

{% tab label="Python" %}
```python
"""
Cancel experiment returns "The experiment was canceled and unlinked from its feature flag allocations." response
"""

from os import environ
from datadog_api_client import ApiClient, Configuration
from datadog_api_client.v2.api.experiments_api import ExperimentsApi
from datadog_api_client.v2.model.experiments_cancel_experiment_v2_request import ExperimentsCancelExperimentV2Request
from datadog_api_client.v2.model.experiments_cancel_experiment_v2_request_data import (
    ExperimentsCancelExperimentV2RequestData,
)
from datadog_api_client.v2.model.experiments_cancel_experiment_v2_request_data_attributes import (
    ExperimentsCancelExperimentV2RequestDataAttributes,
)
from datadog_api_client.v2.model.experiments_cancel_experiment_v2_request_data_type import (
    ExperimentsCancelExperimentV2RequestDataType,
)

# there is a valid "experiment" in the system
EXPERIMENT_DATA_ID = environ["EXPERIMENT_DATA_ID"]

body = ExperimentsCancelExperimentV2Request(
    data=ExperimentsCancelExperimentV2RequestData(
        type=ExperimentsCancelExperimentV2RequestDataType.CANCEL_EXPERIMENT_REQUEST,
        attributes=ExperimentsCancelExperimentV2RequestDataAttributes(
            reason="Cancel the test experiment",
        ),
    ),
)

configuration = Configuration()
configuration.access_token = environ["DD_BEARER_TOKEN"]
with ApiClient(configuration) as api_client:
    api_instance = ExperimentsApi(api_client)
    api_instance.cancel_experiment(experiment_id=EXPERIMENT_DATA_ID, body=body)
```

#### Instructions

First [install the library and its dependencies](https://dnd37xeb23o8n.cloudfront.net/api/latest.md?code-lang=python) and then save the example to `example.py` and run following commands:

```bash
DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" python3 "example.py"
```
{% /tab %}

{% tab label="Ruby" %}
```ruby
# Cancel experiment returns "The experiment was canceled and unlinked from its feature flag allocations." response

require "datadog_api_client"
DatadogAPIClient.configure do |config|
  config.access_token = ENV["DD_BEARER_TOKEN"]
end
api_instance = DatadogAPIClient::V2::ExperimentsAPI.new

# there is a valid "experiment" in the system
EXPERIMENT_DATA_ID = ENV["EXPERIMENT_DATA_ID"]

body = DatadogAPIClient::V2::ExperimentsCancelExperimentV2Request.new({
  data: DatadogAPIClient::V2::ExperimentsCancelExperimentV2RequestData.new({
    type: DatadogAPIClient::V2::ExperimentsCancelExperimentV2RequestDataType::CANCEL_EXPERIMENT_REQUEST,
    attributes: DatadogAPIClient::V2::ExperimentsCancelExperimentV2RequestDataAttributes.new({
      reason: "Cancel the test experiment",
    }),
  }),
})
api_instance.cancel_experiment(EXPERIMENT_DATA_ID, body)
```

#### Instructions

First [install the library and its dependencies](https://dnd37xeb23o8n.cloudfront.net/api/latest.md?code-lang=ruby) and then save the example to `example.rb` and run following commands:

```bash
DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" rb "example.rb"
```
{% /tab %}

{% tab label="Rust" %}
```rust
// Cancel experiment returns "The experiment was canceled and unlinked from its
// feature flag allocations." response
use datadog_api_client::datadog;
use datadog_api_client::datadogV2::api_experiments::ExperimentsAPI;
use datadog_api_client::datadogV2::model::ExperimentsCancelExperimentV2Request;
use datadog_api_client::datadogV2::model::ExperimentsCancelExperimentV2RequestData;
use datadog_api_client::datadogV2::model::ExperimentsCancelExperimentV2RequestDataAttributes;
use datadog_api_client::datadogV2::model::ExperimentsCancelExperimentV2RequestDataType;

#[tokio::main]
async fn main() {
    // there is a valid "experiment" in the system
    let experiment_data_id =
        uuid::Uuid::parse_str(&std::env::var("EXPERIMENT_DATA_ID").unwrap()).expect("Invalid UUID");
    let body =
        ExperimentsCancelExperimentV2Request::new(ExperimentsCancelExperimentV2RequestData::new(
            ExperimentsCancelExperimentV2RequestDataAttributes::new(
                "Cancel the test experiment".to_string(),
            ),
            ExperimentsCancelExperimentV2RequestDataType::CANCEL_EXPERIMENT_REQUEST,
        ));
    let configuration = datadog::Configuration::new();
    let api = ExperimentsAPI::with_config(configuration);
    let resp = api
        .cancel_experiment(experiment_data_id.clone(), body)
        .await;
    if let Ok(value) = resp {
        println!("{:#?}", value);
    } else {
        println!("{:#?}", resp.unwrap_err());
    }
}
```

#### Instructions

First [install the library and its dependencies](https://dnd37xeb23o8n.cloudfront.net/api/latest.md?code-lang=rust) and then save the example to `src/main.rs` and run following commands:

```bash
DD_SITE="datadoghq.com" DD_API_KEY="<DD_API_KEY>" DD_APP_KEY="<DD_APP_KEY>" cargo run
```
{% /tab %}
{% /tabs %}