Outbound webhooks overview

Get signed HTTPS requests from Base44 when an app in your workspace changes or the AI finishes working on a message, without polling for it.

Outbound webhooks send a signed HTTPS request to your service when an app in your workspace changes, or when the AI starts or finishes working on a message. Instead of polling for new or updated apps, your system hears about each change as it happens, including deletes.

Use outbound webhooks to:

• Keep your own records in sync when apps are created, published, taken offline, moved to trash or restored.
• Start your own workflows when an app goes live.
• Know when the AI has finished working on a message you sent, without polling.
• Build a platform on Base44 that reacts to what your customers do in their workspaces.

Outbound webhooks are available on the Business and Enterprise plans.

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How it works

You register an HTTPS URL, called an endpoint, and choose the events it receives. Base44 then sends each matching event to that URL as a JSON POST.

1. Register an endpoint. In your workspace settings, or with a workspace API key. See Setting up endpoints.
2. Activate it. Base44 sends a signed webhook.test.v1 event, and your receiver returns its data.challenge value. When you register with the API, this happens in the same call. Until then the endpoint stays Pending and receives nothing.
3. Verify each request. Every request is signed with your workspace’s Ed25519 key. See Verifying requests.
4. Handle retries. Delivery is at least once, so the same event can arrive more than once. See Delivery and retries.

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Request format

Each request body is a CloudEvents 1.0 JSON document, signed with the Standard Webhooks headers. The data object carries identifiers, timestamps and fixed status values only, never app content or personal data.

{
  "specversion": "1.0",
  "id": "evt_68c1d2e3f4a5b6c7d8e9f0a1",
  "source": "https://base44.com/workspaces/68a1b2c3d4e5f6a7b8c9d0e1",
  "type": "app.published.v1",
  "subject": "apps/68b0c1d2e3f4a5b6c7d8e9f0",
  "time": "2026-09-01T10:15:30.123Z",
  "datacontenttype": "application/json",
  "dataschema": "https://base44.com/webhooks/schemas/app.published.v1.json",
  "authtype": "user",
  "authid": "6899aabbccddeeff00112233",
  "data": {
    "app_id": "68b0c1d2e3f4a5b6c7d8e9f0",
    "workspace_id": "68a1b2c3d4e5f6a7b8c9d0e1",
    "owner_id": "6899aabbccddeeff00112233",
    "published_version": "68c2d3e4f5a6b7c8d9e0f1a2",
    "published_at": "2026-09-01T10:15:30.123Z"
  }
}

For every event type and its fields, see Event types.

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Limits

These limits apply to every workspace.

Limit	Value
Endpoints per workspace	10
Event size	64 KB
Time your receiver has to answer a delivery	15 seconds
Time your receiver has to answer the activation test	5 seconds
Delivery attempts per event	8, over about 27.5 hours