Create Experiment

curl --request POST \
  --url https://api.whop.com/api/v1/experiments \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "account_id": "internal",
  "flag_key": "checkout_redesign_v2",
  "bucket_by": "user",
  "control": {
    "related_resource": {
      "id": "<string>",
      "object": "app"
    }
  },
  "feature_flag_only": true,
  "hypothesis": "If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.",
  "name": "Checkout Redesign V2",
  "related_resource": {
    "id": "<string>",
    "object": "app"
  },
  "targeting_rules": [
    {
      "conditions": [
        {
          "operator": "any",
          "type": "user_id",
          "value": "<unknown>",
          "field": "<string>"
        }
      ],
      "type": "include"
    }
  ],
  "variants": [
    {
      "name": "treatment",
      "weight": 50,
      "related_resource": {
        "id": "<string>",
        "object": "app"
      }
    }
  ]
}
'

import requests

url = "https://api.whop.com/api/v1/experiments"

payload = {
    "account_id": "internal",
    "flag_key": "checkout_redesign_v2",
    "bucket_by": "user",
    "control": { "related_resource": {
            "id": "<string>",
            "object": "app"
        } },
    "feature_flag_only": True,
    "hypothesis": "If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.",
    "name": "Checkout Redesign V2",
    "related_resource": {
        "id": "<string>",
        "object": "app"
    },
    "targeting_rules": [
        {
            "conditions": [
                {
                    "operator": "any",
                    "type": "user_id",
                    "value": "<unknown>",
                    "field": "<string>"
                }
            ],
            "type": "include"
        }
    ],
    "variants": [
        {
            "name": "treatment",
            "weight": 50,
            "related_resource": {
                "id": "<string>",
                "object": "app"
            }
        }
    ]
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    account_id: 'internal',
    flag_key: 'checkout_redesign_v2',
    bucket_by: 'user',
    control: {related_resource: {id: '<string>', object: 'app'}},
    feature_flag_only: true,
    hypothesis: 'If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.',
    name: 'Checkout Redesign V2',
    related_resource: {id: '<string>', object: 'app'},
    targeting_rules: [
      {
        conditions: [{operator: 'any', type: 'user_id', value: '<unknown>', field: '<string>'}],
        type: 'include'
      }
    ],
    variants: [
      {
        name: 'treatment',
        weight: 50,
        related_resource: {id: '<string>', object: 'app'}
      }
    ]
  })
};

fetch('https://api.whop.com/api/v1/experiments', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.whop.com/api/v1/experiments",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'account_id' => 'internal',
    'flag_key' => 'checkout_redesign_v2',
    'bucket_by' => 'user',
    'control' => [
        'related_resource' => [
                'id' => '<string>',
                'object' => 'app'
        ]
    ],
    'feature_flag_only' => true,
    'hypothesis' => 'If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.',
    'name' => 'Checkout Redesign V2',
    'related_resource' => [
        'id' => '<string>',
        'object' => 'app'
    ],
    'targeting_rules' => [
        [
                'conditions' => [
                                [
                                                                'operator' => 'any',
                                                                'type' => 'user_id',
                                                                'value' => '<unknown>',
                                                                'field' => '<string>'
                                ]
                ],
                'type' => 'include'
        ]
    ],
    'variants' => [
        [
                'name' => 'treatment',
                'weight' => 50,
                'related_resource' => [
                                'id' => '<string>',
                                'object' => 'app'
                ]
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.whop.com/api/v1/experiments"

	payload := strings.NewReader("{\n  \"account_id\": \"internal\",\n  \"flag_key\": \"checkout_redesign_v2\",\n  \"bucket_by\": \"user\",\n  \"control\": {\n    \"related_resource\": {\n      \"id\": \"<string>\",\n      \"object\": \"app\"\n    }\n  },\n  \"feature_flag_only\": true,\n  \"hypothesis\": \"If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.\",\n  \"name\": \"Checkout Redesign V2\",\n  \"related_resource\": {\n    \"id\": \"<string>\",\n    \"object\": \"app\"\n  },\n  \"targeting_rules\": [\n    {\n      \"conditions\": [\n        {\n          \"operator\": \"any\",\n          \"type\": \"user_id\",\n          \"value\": \"<unknown>\",\n          \"field\": \"<string>\"\n        }\n      ],\n      \"type\": \"include\"\n    }\n  ],\n  \"variants\": [\n    {\n      \"name\": \"treatment\",\n      \"weight\": 50,\n      \"related_resource\": {\n        \"id\": \"<string>\",\n        \"object\": \"app\"\n      }\n    }\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.whop.com/api/v1/experiments")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"account_id\": \"internal\",\n  \"flag_key\": \"checkout_redesign_v2\",\n  \"bucket_by\": \"user\",\n  \"control\": {\n    \"related_resource\": {\n      \"id\": \"<string>\",\n      \"object\": \"app\"\n    }\n  },\n  \"feature_flag_only\": true,\n  \"hypothesis\": \"If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.\",\n  \"name\": \"Checkout Redesign V2\",\n  \"related_resource\": {\n    \"id\": \"<string>\",\n    \"object\": \"app\"\n  },\n  \"targeting_rules\": [\n    {\n      \"conditions\": [\n        {\n          \"operator\": \"any\",\n          \"type\": \"user_id\",\n          \"value\": \"<unknown>\",\n          \"field\": \"<string>\"\n        }\n      ],\n      \"type\": \"include\"\n    }\n  ],\n  \"variants\": [\n    {\n      \"name\": \"treatment\",\n      \"weight\": 50,\n      \"related_resource\": {\n        \"id\": \"<string>\",\n        \"object\": \"app\"\n      }\n    }\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.whop.com/api/v1/experiments")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"account_id\": \"internal\",\n  \"flag_key\": \"checkout_redesign_v2\",\n  \"bucket_by\": \"user\",\n  \"control\": {\n    \"related_resource\": {\n      \"id\": \"<string>\",\n      \"object\": \"app\"\n    }\n  },\n  \"feature_flag_only\": true,\n  \"hypothesis\": \"If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.\",\n  \"name\": \"Checkout Redesign V2\",\n  \"related_resource\": {\n    \"id\": \"<string>\",\n    \"object\": \"app\"\n  },\n  \"targeting_rules\": [\n    {\n      \"conditions\": [\n        {\n          \"operator\": \"any\",\n          \"type\": \"user_id\",\n          \"value\": \"<unknown>\",\n          \"field\": \"<string>\"\n        }\n      ],\n      \"type\": \"include\"\n    }\n  ],\n  \"variants\": [\n    {\n      \"name\": \"treatment\",\n      \"weight\": 50,\n      \"related_resource\": {\n        \"id\": \"<string>\",\n        \"object\": \"app\"\n      }\n    }\n  ]\n}"

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

{
  "account_id": "internal",
  "assignment_seed": "verb_end_exp1768435200",
  "configuration_revision": 2,
  "control": {
    "related_resource": {
      "id": "<string>",
      "object": "app"
    }
  },
  "flag_key": "verb_end_exp",
  "id": "expt_xxxxxxxxxxxxxx",
  "name": "Verb End",
  "related_resource": {
    "id": "<string>",
    "object": "app"
  },
  "status": "ended",
  "targeting_rules": [
    {
      "conditions": [
        {
          "operator": "any",
          "type": "user_id",
          "value": "<unknown>",
          "field": "<string>"
        }
      ],
      "type": "include"
    }
  ],
  "updated_at": "2026-01-01T12:00:00.000Z",
  "variants": [
    {
      "name": "treatment",
      "weight": 50,
      "ranges": [
        [
          0,
          50
        ]
      ],
      "related_resource": {
        "id": "<string>",
        "object": "app"
      }
    }
  ],
  "bucket_by": "user",
  "created_at": "2026-01-01T12:00:00.000Z",
  "created_by": "user_xxxxxxxxxxxxxx",
  "ended_at": "2026-01-01T12:00:00.000Z",
  "feature_flag_only": false,
  "findings": "Treatment lifted conversion 8%",
  "hypothesis": "Users will convert more",
  "started_at": "2026-01-01T12:00:00.000Z",
  "winning_arm": "treatment"
}

{
  "error": {
    "message": "account_id is required",
    "type": "bad_request",
    "code": "<string>"
  }
}

POST

experiments

Create Experiment

curl --request POST \
  --url https://api.whop.com/api/v1/experiments \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "account_id": "internal",
  "flag_key": "checkout_redesign_v2",
  "bucket_by": "user",
  "control": {
    "related_resource": {
      "id": "<string>",
      "object": "app"
    }
  },
  "feature_flag_only": true,
  "hypothesis": "If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.",
  "name": "Checkout Redesign V2",
  "related_resource": {
    "id": "<string>",
    "object": "app"
  },
  "targeting_rules": [
    {
      "conditions": [
        {
          "operator": "any",
          "type": "user_id",
          "value": "<unknown>",
          "field": "<string>"
        }
      ],
      "type": "include"
    }
  ],
  "variants": [
    {
      "name": "treatment",
      "weight": 50,
      "related_resource": {
        "id": "<string>",
        "object": "app"
      }
    }
  ]
}
'

import requests

url = "https://api.whop.com/api/v1/experiments"

payload = {
    "account_id": "internal",
    "flag_key": "checkout_redesign_v2",
    "bucket_by": "user",
    "control": { "related_resource": {
            "id": "<string>",
            "object": "app"
        } },
    "feature_flag_only": True,
    "hypothesis": "If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.",
    "name": "Checkout Redesign V2",
    "related_resource": {
        "id": "<string>",
        "object": "app"
    },
    "targeting_rules": [
        {
            "conditions": [
                {
                    "operator": "any",
                    "type": "user_id",
                    "value": "<unknown>",
                    "field": "<string>"
                }
            ],
            "type": "include"
        }
    ],
    "variants": [
        {
            "name": "treatment",
            "weight": 50,
            "related_resource": {
                "id": "<string>",
                "object": "app"
            }
        }
    ]
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    account_id: 'internal',
    flag_key: 'checkout_redesign_v2',
    bucket_by: 'user',
    control: {related_resource: {id: '<string>', object: 'app'}},
    feature_flag_only: true,
    hypothesis: 'If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.',
    name: 'Checkout Redesign V2',
    related_resource: {id: '<string>', object: 'app'},
    targeting_rules: [
      {
        conditions: [{operator: 'any', type: 'user_id', value: '<unknown>', field: '<string>'}],
        type: 'include'
      }
    ],
    variants: [
      {
        name: 'treatment',
        weight: 50,
        related_resource: {id: '<string>', object: 'app'}
      }
    ]
  })
};

fetch('https://api.whop.com/api/v1/experiments', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.whop.com/api/v1/experiments",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'account_id' => 'internal',
    'flag_key' => 'checkout_redesign_v2',
    'bucket_by' => 'user',
    'control' => [
        'related_resource' => [
                'id' => '<string>',
                'object' => 'app'
        ]
    ],
    'feature_flag_only' => true,
    'hypothesis' => 'If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.',
    'name' => 'Checkout Redesign V2',
    'related_resource' => [
        'id' => '<string>',
        'object' => 'app'
    ],
    'targeting_rules' => [
        [
                'conditions' => [
                                [
                                                                'operator' => 'any',
                                                                'type' => 'user_id',
                                                                'value' => '<unknown>',
                                                                'field' => '<string>'
                                ]
                ],
                'type' => 'include'
        ]
    ],
    'variants' => [
        [
                'name' => 'treatment',
                'weight' => 50,
                'related_resource' => [
                                'id' => '<string>',
                                'object' => 'app'
                ]
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.whop.com/api/v1/experiments"

	payload := strings.NewReader("{\n  \"account_id\": \"internal\",\n  \"flag_key\": \"checkout_redesign_v2\",\n  \"bucket_by\": \"user\",\n  \"control\": {\n    \"related_resource\": {\n      \"id\": \"<string>\",\n      \"object\": \"app\"\n    }\n  },\n  \"feature_flag_only\": true,\n  \"hypothesis\": \"If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.\",\n  \"name\": \"Checkout Redesign V2\",\n  \"related_resource\": {\n    \"id\": \"<string>\",\n    \"object\": \"app\"\n  },\n  \"targeting_rules\": [\n    {\n      \"conditions\": [\n        {\n          \"operator\": \"any\",\n          \"type\": \"user_id\",\n          \"value\": \"<unknown>\",\n          \"field\": \"<string>\"\n        }\n      ],\n      \"type\": \"include\"\n    }\n  ],\n  \"variants\": [\n    {\n      \"name\": \"treatment\",\n      \"weight\": 50,\n      \"related_resource\": {\n        \"id\": \"<string>\",\n        \"object\": \"app\"\n      }\n    }\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.whop.com/api/v1/experiments")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"account_id\": \"internal\",\n  \"flag_key\": \"checkout_redesign_v2\",\n  \"bucket_by\": \"user\",\n  \"control\": {\n    \"related_resource\": {\n      \"id\": \"<string>\",\n      \"object\": \"app\"\n    }\n  },\n  \"feature_flag_only\": true,\n  \"hypothesis\": \"If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.\",\n  \"name\": \"Checkout Redesign V2\",\n  \"related_resource\": {\n    \"id\": \"<string>\",\n    \"object\": \"app\"\n  },\n  \"targeting_rules\": [\n    {\n      \"conditions\": [\n        {\n          \"operator\": \"any\",\n          \"type\": \"user_id\",\n          \"value\": \"<unknown>\",\n          \"field\": \"<string>\"\n        }\n      ],\n      \"type\": \"include\"\n    }\n  ],\n  \"variants\": [\n    {\n      \"name\": \"treatment\",\n      \"weight\": 50,\n      \"related_resource\": {\n        \"id\": \"<string>\",\n        \"object\": \"app\"\n      }\n    }\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.whop.com/api/v1/experiments")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"account_id\": \"internal\",\n  \"flag_key\": \"checkout_redesign_v2\",\n  \"bucket_by\": \"user\",\n  \"control\": {\n    \"related_resource\": {\n      \"id\": \"<string>\",\n      \"object\": \"app\"\n    }\n  },\n  \"feature_flag_only\": true,\n  \"hypothesis\": \"If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe.\",\n  \"name\": \"Checkout Redesign V2\",\n  \"related_resource\": {\n    \"id\": \"<string>\",\n    \"object\": \"app\"\n  },\n  \"targeting_rules\": [\n    {\n      \"conditions\": [\n        {\n          \"operator\": \"any\",\n          \"type\": \"user_id\",\n          \"value\": \"<unknown>\",\n          \"field\": \"<string>\"\n        }\n      ],\n      \"type\": \"include\"\n    }\n  ],\n  \"variants\": [\n    {\n      \"name\": \"treatment\",\n      \"weight\": 50,\n      \"related_resource\": {\n        \"id\": \"<string>\",\n        \"object\": \"app\"\n      }\n    }\n  ]\n}"

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

{
  "account_id": "internal",
  "assignment_seed": "verb_end_exp1768435200",
  "configuration_revision": 2,
  "control": {
    "related_resource": {
      "id": "<string>",
      "object": "app"
    }
  },
  "flag_key": "verb_end_exp",
  "id": "expt_xxxxxxxxxxxxxx",
  "name": "Verb End",
  "related_resource": {
    "id": "<string>",
    "object": "app"
  },
  "status": "ended",
  "targeting_rules": [
    {
      "conditions": [
        {
          "operator": "any",
          "type": "user_id",
          "value": "<unknown>",
          "field": "<string>"
        }
      ],
      "type": "include"
    }
  ],
  "updated_at": "2026-01-01T12:00:00.000Z",
  "variants": [
    {
      "name": "treatment",
      "weight": 50,
      "ranges": [
        [
          0,
          50
        ]
      ],
      "related_resource": {
        "id": "<string>",
        "object": "app"
      }
    }
  ],
  "bucket_by": "user",
  "created_at": "2026-01-01T12:00:00.000Z",
  "created_by": "user_xxxxxxxxxxxxxx",
  "ended_at": "2026-01-01T12:00:00.000Z",
  "feature_flag_only": false,
  "findings": "Treatment lifted conversion 8%",
  "hypothesis": "Users will convert more",
  "started_at": "2026-01-01T12:00:00.000Z",
  "winning_arm": "treatment"
}

{
  "error": {
    "message": "account_id is required",
    "type": "bad_request",
    "code": "<string>"
  }
}

Authorizations

Authorization

string

header

required

An Account API key, account-scoped JWT, App API key, or user OAuth token. Prepend the key or token with Bearer, for example Bearer ***************************.

Headers

Idempotency-Key

string

A unique key that makes this request safe to retry. See Idempotent requests.

Maximum string length: 255

Example:

"d9105228-4a08-46b1-8b91-42fed586d383"

Api-Version-Date

string

Pins the request to a dated API version.

Example:

"2026-09-11"

Body

application/json

account_id

string

required

Owning account tag or internal. Required; ownership cannot change.

Example:

"internal"

flag_key

string

required

Developer-chosen handle referenced from code, used in evaluation and results calls. Interchangeable with the returned expt_ id anywhere the API takes an experiment identifier.

Example:

"checkout_redesign_v2"

bucket_by

enum<string>

Randomization unit, and the only identity the assignment is keyed on — evaluation fails rather than falling back to another. user (default) uses subject[user_id] for account experiments and the signed-in user for internal experiments; account uses subject[account_id], so every user of an account gets the same arm; anonymous uses the anonymous id and survives sign-in. Fixed after creation.

Available options:

user,

account,

anonymous

Example:

"user"

control

object

Show child attributes

feature_flag_only

boolean

When true, creates a binary feature flag rather than a full experiment. Feature flags expose the same evaluation API but do not collect metric results. Defaults to false.

hypothesis

string | null

Required for full experiments; rejected on feature flags. Structure it as "If we [change] for [cohort], then [measurable behavior] will [increase/decrease], resulting in [business outcome], because [evidence]. Created by [name]." Evidence should be something real — a baseline number, a funnel breakdown — not a guess, and [name] is you, not something to leave blank.

Example:

"If we send a blueprint nudge email 30 minutes after business creation, then GTV within 10 hours will increase among newly created businesses, resulting in more new business operators generating GTV within 10 hours, because operators currently land on an empty dashboard with no concrete next step. Created by Jane Doe."

name

string

Human-readable display name. Defaults to flag_key when omitted.

Example:

"Checkout Redesign V2"

Show child attributes

targeting_rules

object[]

Rules that determine which subjects qualify for the experiment.

Show child attributes

variants

object[]

Treatment arms to create. Users outside every arm form the implicit control group. Required unless feature_flag_only is true.

Show child attributes

Response

experiment created

account_id

string

required

Owning account ID, or internal for Whop platform experiments.

Example:

"internal"

assignment_seed

string

required

Assignment hashes UTF-8 seed + subject ID with CRC32 modulo 100 and selects the stored end-exclusive range.

Example:

"verb_end_exp1768435200"

configuration_revision

integer

required

Revision of the serving configuration. Does not change the assignment seed.

Example:

2

control

object

required

Show child attributes

flag_key

string

required

Developer-chosen handle referenced from code. Anywhere the API takes an experiment identifier, the expt_ id and the flag_key are interchangeable.

Example:

"verb_end_exp"

string

required

Unique identifier for the experiment, prefixed expt_.

Example:

"expt_xxxxxxxxxxxxxx"

name

string

required

Human-readable display name.

Example:

"Verb End"

Show child attributes

status

enum<string>

required

Lifecycle state. draft — not yet live; active — currently running; paused — traffic paused; ended — concluded.

Available options:

draft,

active,

paused,

ended

Example:

"ended"

targeting_rules

object[]

required

Rules gating who is in the experiment at all. Conditions within a rule are AND-ed, rules are OR-ed, and exclude rules always win. Empty means everyone qualifies.

Show child attributes

updated_at

string<date_time> | null

required

Example:

"2026-01-01T12:00:00.000Z"

variants

object[]

required

Treatment arms. Users outside every arm's allocation form the implicit control group. Weights only ever grow and arms are never removed, so a user moves from control into a treatment at most once.

Show child attributes

bucket_by

enum<string> | null

Randomization unit — user buckets each user independently, account buckets whole accounts (every user of an account gets the same arm). null for feature flags.

Available options:

user,

account,

anonymous

Example:

"user"

created_at

string | null

When the experiment was created, as an ISO 8601 timestamp.

Example:

"2026-01-01T12:00:00.000Z"

created_by

string | null

ID of the user who created the experiment, prefixed user_. null for experiments created before creators were recorded.

Example:

"user_xxxxxxxxxxxxxx"

ended_at

string | null

When the experiment stopped collecting data, as an ISO 8601 timestamp. null while still running.

Example:

"2026-01-01T12:00:00.000Z"

feature_flag_only

boolean | null

true when this was created as a feature flag rather than a full experiment. Feature flags share the same evaluation API but do not collect metric results.

Example:

false

findings

string | null

What was learned and why this outcome, recorded when the experiment was ended. null until then.

Example:

"Treatment lifted conversion 8%"

hypothesis

string | null

Hypothesis for this experiment. null when none is set, and always null for feature flags.

Example:

"Users will convert more"

started_at

string | null

When the experiment began collecting data, as an ISO 8601 timestamp. null for drafts.

Example:

"2026-01-01T12:00:00.000Z"

winning_arm

string | null

The treatment that won, set when the experiment was ended. Once set, every evaluation returns this arm to every caller regardless of targeting or allocation, and no further exposures are recorded. null means control won — an ended experiment with no winning arm evaluates to control for everyone. Always null for feature flags, which simply evaluate to disabled once ended.

Example:

"treatment"

Introduction

Reference

Webhooks & Events

Core Resources

Notifications

Payments

Money

Commerce

Partners

Workforce

Tracking

Ads

Media

Identity

Developer

Create Experiment

Authorizations

Headers

Body

Response