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

# Verify Signal ingestion

> Complete Signal activation with the identity-free server verification event.

After your collection hostname becomes active, PlainRouter requires one server-side verification event to confirm that Signal ingestion works end to end. Browser pixel traffic does not complete this activation check.

<Card title="What the verification does" icon="badge-check">
  It writes one idempotent, identity-free `signal_verification` event to the authorized Signal ledger. It does not contact Meta, enter attribution or enforcement, or create spend.
</Card>

## Before you begin

You need:

* An active collection hostname.
* Either the Signal tracker secret for REST authentication or an MCP connection with `signals.verify`.

## Verify with the REST API

Send an authenticated request with no body:

```bash theme={null}
curl https://plainrouter.com/api/v1/verification-events \
  --request POST \
  --header "Authorization: Bearer $PLAINROUTER_SIGNAL_SECRET" \
  --header "Accept: application/json"
```

A new verification returns HTTP `202`:

```json theme={null}
{
  "event_id": "signal_verification",
  "duplicate": false
}
```

Repeating the request is safe. It returns HTTP `200` with `duplicate: true` and does not create another ledger event.

<Warning>
  Keep the tracker secret on your server. Never put it in browser code, a URL, source control, a prompt, or a log.
</Warning>

## Verify with MCP

If you already have an authorized PlainRouter MCP connection, ask the client to call:

```text theme={null}
verify_signal_ingestion
```

The tool accepts no input. It uses the Signal in the authorized workspace and returns the same `event_id` and `duplicate` fields as the REST endpoint.

The connection needs the `signals.verify` permission. Read-tier workspace tokens include this permission. See [Connect an AI agent](/docs/actions/connect-agent) or [Workspace tokens](/docs/actions/workspace-tokens).

## Confirm activation

PlainRouter polls setup progress automatically. Once the verification event is present and the collection hostname remains active, the setup screen completes.

You can then:

* [Install the optional Signals pixel](/docs/signals/install-pixel) for consent-aware browser measurement.
* [Submit server conversion events](/docs/reference/conversion-api).
* [Connect Meta](/docs/signals/connect-meta) for eligible destination delivery.

## Troubleshoot

### The API returns `401`

The Signal tracker secret is missing, invalid, or belongs to another environment. Confirm the bearer header and replace a stopped credential.

### MCP reports insufficient permission

Reconnect with `signals.verify`, or issue a new workspace token with the Read tier or higher.

### MCP cannot find an active Signal

Confirm that the authorized workspace is the workspace containing the Signal and that its collection hostname has completed validation.

### Setup still does not complete

Confirm the collection hostname is still **Active**, then repeat the idempotent verification request. Installing or visiting the browser pixel does not replace this server-side check.