---
title: Cancel experiment
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: Docs > API Reference > Experiments
---

> For the complete documentation index, see [llms.txt](https://docs.datadoghq.com/llms.txt).

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com, us2.ddog-gov.com

{% alert level="danger" %}
This product is not supported for your selected [Datadog site](https://docs.datadoghq.com/getting_started/site.md). ({% placeholder "user-datadog-site-name" /%}).
{% /alert %}

{% /callout %}

# Cancel experiment{% #cancel-experiment %}

{% tab title="v2" %}

| Datadog site      | API endpoint                                                                 |
| ----------------- | ---------------------------------------------------------------------------- |
| 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 |
| app.datadoghq.eu  | POST https://api.datadoghq.eu/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  |
| uk1.datadoghq.com | POST https://api.uk1.datadoghq.com/api/v2/experiments/{experiment_id}/cancel |
| 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 |

### 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://docs.datadoghq.com/api/latest/scopes.md#experiments) to access this endpoint.



### Arguments

#### Path Parameters

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

### Request

#### Body Data (required)



{% tab title="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`                          |

{% /tab %}

{% tab title="Example" %}

```json
{
  "data": {
    "type": "cancel-experiment-request",
    "attributes": {
      "reason": "Cancel the test experiment"
    }
  }
}
```

{% /tab %}

### Response

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

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

{% /tab %}

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

{% /tab %}

{% tab title="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.
{% tab title="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 title="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 %}

{% /tab %}

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

{% /tab %}

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

{% /tab %}

{% tab title="429" %}
Too many requests
{% tab title="Model" %}
API error response.

| Field                    | Type     | Description       |
| ------------------------ | -------- | ----------------- |
| errors [*required*] | [string] | A list of errors. |

{% /tab %}

{% tab title="Example" %}

```json
{
  "errors": [
    "Bad Request"
  ]
}
```

{% /tab %}

{% /tab %}

### Code Example

##### 
                          \## default
# 
 \# Path parameters export experiment_id="550e8400-e29b-41d4-a716-446655440000" \# Use a Personal Access Token or Service Access Token export DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>"  \# Curl command curl -X POST "https://api.datadoghq.com/api/v2/experiments/${experiment_id}/cancel" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer ${DD_BEARER_TOKEN}" \
-d @- << EOF
{
  "data": {
    "attributes": {
      "reason": "Experiment configuration was incorrect"
    },
    "type": "cancel-experiment-request"
  }
}
EOF 

                        
##### 

```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://docs.datadoghq.com/api/latest.md?code-lang=go) and then save the example to `main.go` and run following commands:
    DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" go run "main.go"
##### 

```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://docs.datadoghq.com/api/latest.md?code-lang=java) and then save the example to `Example.java` and run following commands:
    DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" java "Example.java"
##### 

```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://docs.datadoghq.com/api/latest.md?code-lang=python) and then save the example to `example.py` and run following commands:
    DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" python3 "example.py"
##### 

```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://docs.datadoghq.com/api/latest.md?code-lang=ruby) and then save the example to `example.rb` and run following commands:
    DD_SITE="datadoghq.com" DD_BEARER_TOKEN="<PERSONAL_ACCESS_TOKEN OR SERVICE_ACCESS_TOKEN>" rb "example.rb"
##### 

```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://docs.datadoghq.com/api/latest.md?code-lang=rust) and then save the example to `src/main.rs` and run following commands:
    DD_SITE="datadoghq.com" DD_API_KEY="<DD_API_KEY>" DD_APP_KEY="<DD_APP_KEY>" cargo run
{% /tab %}