Delete a Holdout

curl --request DELETE \
     --url https://api.optimizely.com/flags/v1//projects/{project_id}/holdouts/{holdout_id} \
     --header 'accept: application/json'

var myHeaders = new Headers();
myHeaders.append("accept", "application/json");
myHeaders.append("content-type", "application/json");

var requestOptions = {
   method: 'DELETE',
   headers: myHeaders,
   redirect: 'follow'
};

fetch("https://api.optimizely.com/flags/v1//projects/{project_id}/holdouts/{holdout_id}", requestOptions)
   .then(response => response.text())
   .then(result => console.log(result))
   .catch(error => console.log('error', error));

require "uri"
require "json"
require "net/http"

url = URI("https://api.optimizely.com/flags/v1//projects/{project_id}/holdouts/{holdout_id}")

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

request = Net::HTTP::Delete.new(url)
request["accept"] = "application/json"
request["content-type"] = "application/json"

response = https.request(request)
puts response.read_body

import requests
import json

url = "https://api.optimizely.com/flags/v1//projects/{project_id}/holdouts/{holdout_id}"

payload = {}
headers = {
   'accept': 'application/json',
   'content-type': 'application/json'
}

response = requests.request("DELETE", url, headers=headers, data=payload)

print(response.text)

// Successfully deleted the holdout. No response body is returned.
Deletion completed:

Holdout configuration permanently removed from database
Associated metrics deleted
All experiment rules and historical data destroyed
Holdout is no longer accessible via any API endpoints

What happens after deletion:

GET requests to this holdout will return 404 Not Found
The holdout will not appear in list responses
Associated URLs (update_url, fetch_url, etc.) become invalid
Any references to this holdout in other systems should be cleaned up

A successful 204 response confirms the holdout has been completely removed from all systems.

// Bad Request - Invalid request parameters or malformed holdout ID.
Common causes:

Invalid holdout_id format (must be a positive integer)
Invalid project_id format (must be a positive integer)
Malformed request structure
{
  "detail": "",
  "status": 0,
  "title": "",
  "type": "",
  "uuid": ""
}

// Invalid credentials

// Forbidden - You don't have permission to delete holdouts in this project.
Permission requirements:

Must have project-level access
Must have holdout deletion permissions
Holdouts feature must be enabled for this project

Common causes:

Insufficient user permissions for destructive operations
Project-level permissions don't include holdout management
Organization-level policies restrict holdout deletion
Holdouts feature flag is disabled for this project
{
  "detail": "",
  "status": 0,
  "title": "",
  "type": "",
  "uuid": ""
}

// Forbidden - You don't have permission to delete holdouts in this project.
Permission requirements:

Must have project-level access
Must have holdout deletion permissions
Holdouts feature must be enabled for this project

Common causes:

Insufficient user permissions for destructive operations
Project-level permissions don't include holdout management
Organization-level policies restrict holdout deletion
Holdouts feature flag is disabled for this project
{
  "detail": "",
  "status": 0,
  "title": "",
  "type": "",
  "uuid": ""
}

// Holdouts feature disabled
{
  "detail": "Holdouts feature is not enabled for this project",
  "status": 403,
  "title": "Feature not enabled",
  "type": "about:blank"
}

// Insufficient permissions
{
  "detail": "Permission denied - insufficient privileges to delete holdouts",
  "status": 403,
  "title": "Forbidden",
  "type": "about:blank"
}

// Not Found - The specified holdout does not exist or has already been deleted.
Possible reasons:

Holdout ID does not exist in the specified project
Project ID does not exist or you don't have access to it
Holdout was already deleted by another user/process
Insufficient permissions to view or delete this holdout

Note: This is also returned if the holdout exists but you lack delete permissions,
for security reasons (to prevent ID enumeration attacks).
{
  "detail": "",
  "status": 0,
  "title": "",
  "type": "",
  "uuid": ""
}

// Not Found - The specified holdout does not exist or has already been deleted.
Possible reasons:

Holdout ID does not exist in the specified project
Project ID does not exist or you don't have access to it
Holdout was already deleted by another user/process
Insufficient permissions to view or delete this holdout

Note: This is also returned if the holdout exists but you lack delete permissions,
for security reasons (to prevent ID enumeration attacks).
{
  "detail": "",
  "status": 0,
  "title": "",
  "type": "",
  "uuid": ""
}

// Holdout does not exist
{
  "detail": "Holdout not found with id '987'",
  "status": 404,
  "title": "Holdout not found",
  "type": "about:blank"
}

// Project does not exist
{
  "detail": "Project not found with id '12345'",
  "status": 404,
  "title": "Project not found",
  "type": "about:blank"
}