Actuators

Actuators are how Apex takes action on the signals it detects. While sensors bring data in, actuators push information out — sending notifications, triggering workflows, and keeping your team informed when something important happens.

Actuator Types

The Actuators page (/dashboard/actuators) shows six execution capabilities:

Actuator	Purpose	Status
Experiments	A/B tests that modify page elements or behavior	Active (core feature)
Tasks	Action items generated from insights	Planned
Budget	Automated budget allocation recommendations	Planned
Approvals	Review gates for high-impact changes	Planned
Outbound Webhooks	HTTP POST to your endpoints when triggers fire	Available
Slack Notifications	Messages to Slack channels when triggers fire	Available

Outbound Webhooks

Webhooks send a JSON payload to your endpoint whenever a configured trigger fires.

Setting Up a Webhook

Navigate to Settings

Open Settings in the dashboard sidebar.

Create a webhook

Add a new notification with type webhook. Provide the URL where Apex should send events.

Choose triggers

Select which events should fire the webhook:

experiment.completed — An experiment reaches statistical significance
experiment.started — A new experiment begins collecting data
task.created — A new task is generated
budget.recommendation — A budget reallocation is suggested
model.drift — Scoring model drift is detected
scoring.changed — A scoring model is activated or modified

Save

Apex generates a signing secret (whsec_...) that you can use to verify webhook authenticity on your end.

Webhook Payload

Each webhook delivery sends a JSON body:

{
  "trigger": "experiment.completed",
  "data": {
    "experimentId": "exp-123",
    "winner": "variant_b",
    "conversionLift": 12.5
  },
  "timestamp": "2026-03-28T15:30:00Z"
}

Verifying Signatures

Every webhook includes an X-Apex-Signature header containing an HMAC-SHA256 signature of the request body, signed with your webhook secret. Verify this signature on your server to ensure the request came from Apex.

Retry Behavior

If your endpoint returns a non-2xx status code, Apex retries up to 3 times with exponential backoff. Each delivery attempt is logged and visible in the delivery log.

Slack Notifications

Slack notifications send formatted messages to a Slack channel via an Incoming Webhook URL.

Setting Up Slack

Create a Slack Incoming Webhook

In your Slack workspace, create an Incoming Webhook and copy the webhook URL.

Add the notification

In Apex Settings, add a new notification with type slack. Paste the webhook URL and optionally specify a channel (defaults to #general).

Choose triggers

Select the same trigger events as webhooks — experiment completions, scoring changes, drift alerts, etc.

Slack messages include an emoji icon, the trigger type as a title, and a summary of the event data.

Delivery Logs

Both webhook and Slack notifications maintain delivery logs. Each log entry records:

The trigger event and timestamp
Whether delivery succeeded or failed
The HTTP status code returned
Retry attempts (if any)

Next Steps

Connect sensors — sensors provide the data that triggers actuator events
Run experiments — experiment lifecycle events can trigger webhooks
Configure scoring models — scoring changes can trigger notifications