Experiments API

Create, manage, and query A/B tests. The active experiments endpoint is public; all others require authentication.

List Experiments

GET/api/experiments

List all experiments for the current project

Returns an array of experiment objects. Optionally filter by status.

Parameter	Type	Description
`status`	`string`	Filter by status: draft, running, paused, or completed

curl https://your-instance.com/api/experiments?status=running \ -H "x-api-key: apex_key_abc123"

Create Experiment

POST/api/experiments

Create a new experiment in draft status

Parameter	Type	Description
`name`required	`string`	Display name for the experiment
`targetUrl`required	`string`	URL pattern where the experiment runs
`variants`required	`array`	Array of variant objects with name and optional css/js modifications
`trafficSplit`	`number`	Percentage of traffic included (0–100). Defaults to 100.
`beliefId`	`string`	Link to a belief this experiment tests
`mode`	`string`	Experiment mode: ab (default), multivariate, or bandit

curl -X POST https://your-instance.com/api/experiments \ -H "Content-Type: application/json" \ -H "x-api-key: apex_key_abc123" \ -d '{ "name": "Pricing CTA Color Test", "targetUrl": "/pricing", "trafficSplit": 50, "variants": [ { "name": "Control" }, { "name": "Green CTA", "css": ".cta-btn { background: #22c55e; }" } ] }'

Update Experiment

PATCH/api/experiments

Update an existing experiment

Parameter	Type	Description
`id`required	`string`	Experiment ID to update
`status`	`string`	Transition status: draft, running, paused, or completed
`name`	`string`	Updated display name
`trafficSplit`	`number`	Updated traffic percentage
`variants`	`array`	Updated variants array

curl -X PATCH https://your-instance.com/api/experiments \ -H "Content-Type: application/json" \ -H "x-api-key: apex_key_abc123" \ -d '{ "id": "exp_abc123", "status": "running" }'

Get Active Experiments (Public)

GET/api/experiments/active

Fetch running experiments for a project — used by the snippet

Parameter	Type	Description
`key`required	`string`	Project key (query parameter)

Info

This endpoint is public and requires no authentication. It is called automatically by the Apex JavaScript snippet to apply experiment variants on page load.

Returns an array of active experiments with their variants and traffic allocation.

Experiment Object

Field	Type	Description
`id`	string	Unique experiment identifier
`name`	string	Display name
`status`	string	`draft`, `running`, `paused`, or `completed`
`targetUrl`	string	URL pattern for targeting
`trafficSplit`	number	Percentage of traffic included
`variants`	array	Variant definitions
`results`	object	Per-variant conversion counts and rates
`confidence`	number	Statistical confidence level (0–1)
`beliefId`	string	Linked belief ID, if any
`mode`	string	`ab`, `multivariate`, or `bandit`