> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dataforb2b.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Monitor

> Subscribe to a signal

Create a monitor — a subscription to a [signal](/api-reference/signals-catalog), delivered to your webhook. An API key can have many monitors.

A monitor is just: **`signal` + `watch` + `url`**.

## Request Body

<ParamField body="signal" type="string" required>
  The signal to subscribe to — `post_engagement`. See [Signal Catalog](/api-reference/signals-catalog).
</ParamField>

<ParamField body="watch" type="string | array" required>
  Who to watch — the author's profile URL. Pass one value or a list (up to **100** per request).
</ParamField>

<ParamField body="url" type="string" required>
  HTTPS endpoint where events are delivered.
</ParamField>

<ParamField body="secret" type="string">
  Optional. When set, deliveries are signed via `X-Webhook-Signature` (HMAC-SHA256 of the body).
</ParamField>

## Response

<ResponseField name="id" type="number">Monitor ID</ResponseField>
<ResponseField name="signal" type="string">The subscribed signal</ResponseField>
<ResponseField name="watch" type="array">What's being watched (the values you gave)</ResponseField>
<ResponseField name="url" type="string">Delivery URL</ResponseField>
<ResponseField name="active" type="boolean">Whether the monitor is active</ResponseField>
<ResponseField name="created_at" type="string">ISO 8601 timestamp</ResponseField>

<RequestExample>
  ```bash Watch one author theme={null}
  curl -X POST https://api.dataforb2b.ai/monitors \
    -H "api_key: YOUR_api_key" -H "Content-Type: application/json" \
    -d '{
      "signal": "post_engagement",
      "watch": "https://www.linkedin.com/in/jane-doe/",
      "url": "https://your-server.com/webhook"
    }'
  ```

  ```bash Watch several authors theme={null}
  curl -X POST https://api.dataforb2b.ai/monitors \
    -H "api_key: YOUR_api_key" -H "Content-Type: application/json" \
    -d '{
      "signal": "post_engagement",
      "watch": [
        "https://www.linkedin.com/in/jane-doe/",
        "https://www.linkedin.com/in/john-roe/"
      ],
      "url": "https://your-server.com/webhook"
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json Response theme={null}
  {
    "id": 42,
    "signal": "post_engagement",
    "watch": ["https://www.linkedin.com/in/jane-doe/"],
    "url": "https://your-server.com/webhook",
    "active": true,
    "created_at": "2026-06-12T10:00:00.000000"
  }
  ```
</ResponseExample>