Experiment - Whop Docs

An Experiment is a feature flag or A/B test owned by an account. Treatments take stable percentage ranges of traffic and everyone else gets control, so growing an allocation never moves an existing user to another arm. Use the Experiments API to create a draft, configure its weights, targeting, and resource bindings, then activate, pause, or end it, and to evaluate which arm a user, account, or anonymous visitor gets. Managing experiments requires experiment:read or experiment:manage; evaluation works without authentication.

Endpoints

Endpoint	Request
List Experiments	GET `/experiments`
Retrieve Experiment	GET `/experiments/{id}`
Evaluate Experiments	GET `/experiments/exposures`
Create Experiment	POST `/experiments`
Activate Experiment	POST `/experiments/{id}/activate`
End Experiment	POST `/experiments/{id}/end`
Pause Experiment	POST `/experiments/{id}/pause`
Update Experiment	PATCH `/experiments/{id}`

Attributes

string

required

Unique identifier for the experiment, prefixed expt_.

string

required

Owning account ID.

string

required

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

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

integer

required

Revision of the serving configuration. Increments on every configuration change, so a cached definition with a lower revision is stale. Does not change the assignment seed.

object

required

Properties

string

required

Referenced resource tag, belonging to the experiment owner.

string

required

Available options: app, app_build, product, plan

string | null

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

string | null

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

string | null

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

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.

string | null

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

string

required

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

string | null

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

string

required

Human-readable display name.

Resource owned by the account that this experiment is bound to, such as an app or product. null when unbound. Fixed once the experiment first activates.

Properties

string

required

Referenced resource tag, belonging to the experiment owner.

string

required

Available options: app, app_build, product, plan

string | null

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

string

required

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

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.

Properties

object[]

required

Conditions within this rule, all of which must match.

Properties

string | null

Property name to read from the user context. Present when type is property.

string

required

Comparison to apply.Available options: any, none, eq, neq, gt, gte, lt, lte

string

required

What the condition matches on: the user ID, the account ID, or a named user property.Available options: user_id, account_id, property

string

required

Value or list of values to match against.

string

include — users matching this rule qualify; exclude — users matching this rule are always excluded, overriding any include rule.Available options: include, exclude

string | null

required

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.

Properties

string

required

Treatment identifier. control is reserved — it is the implicit remainder.

integer[][]

Granted bucket ranges (1% units, end-exclusive) recording this arm’s allocation history. Server-managed; ranges are only ever appended, which is what keeps assignments permanent.

Properties

string

required

Referenced resource tag, belonging to the experiment owner.

string

required

Available options: app, app_build, product, plan

integer

required

Percentage of all users assigned to this treatment, 1–100. All weights together sum to at most 100; the remainder is control.

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.

Experiment

{
	"id": "expt_xxxxxxxxxxxxxx",
	"account_id": "biz_xxxxxxxxxxxxxx",
	"flag_key": "checkout_redesign_v2",
	"name": "Checkout Redesign V2",
	"hypothesis": "A single-step checkout raises conversion.",
	"status": "active",
	"feature_flag_only": false,
	"bucket_by": "user",
	"assignment_seed": "checkout_redesign_v21789462000",
	"configuration_revision": 2,
	"variants": [
		{
			"name": "treatment",
			"weight": 50,
			"ranges": [[0, 50]],
			"related_resource": null
		}
	],
	"control": {
		"related_resource": null
	},
	"related_resource": null,
	"targeting_rules": [
		{
			"type": "include",
			"conditions": [
				{
					"type": "property",
					"field": "country",
					"operator": "eq",
					"value": "US"
				}
			]
		}
	],
	"winning_arm": null,
	"findings": null,
	"created_by": "user_xxxxxxxxxxxxxx",
	"created_at": "2026-09-01T12:00:00.000Z",
	"started_at": "2026-09-02T09:00:00.000Z",
	"ended_at": null,
	"updated_at": "2026-09-02T09:00:00.000Z"
}

​Endpoints

​Attributes

Endpoints

Attributes