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

# GET /head: Retrieve Latest Replication Head Metadata

> Fetch the latest confirmed sequence number, Merkle root, and timestamp for your agent's replication log — a lightweight liveness and sync-check probe.

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The `GET /head` endpoint returns the single most recent confirmed entry in your agent's replication log: its sequence number, Merkle root, and last-updated timestamp. It is a single indexed-column lookup, designed for fast polling — ideal as a pre-flight check before a replay, as a sync-status heartbeat, or to verify that a just-submitted chunk was accepted as the new head.

## Request

```http theme={null}
GET /head
Authorization: Bearer <TOKEN>
```

This endpoint takes no query parameters. The agent is identified entirely from the bearer token.

## Response

### 200 OK

<ResponseField name="sequence_number" type="integer">
  Sequence number of the latest confirmed replication entry for this agent.
</ResponseField>

<ResponseField name="merkle_root" type="string">
  SHA-256 Merkle root recorded at the time the latest chunk was written.
</ResponseField>

<ResponseField name="updated_at" type="string">
  ISO-8601 timestamp of when the current head was last updated.
</ResponseField>

### Example Response

```json theme={null}
{
  "sequence_number": 10,
  "merkle_root": "84c8a8d11d95e0cce8da70c1a96c14b7454f738f65429384f9b4f3b7d1597f8c",
  "updated_at": "2026-06-09T16:45:30.123Z"
}
```

## Errors

<ResponseField name="error" type="string">
  `no_replication_entries` — returned with HTTP 404 when the authenticated agent has not pushed any replication chunks yet. This is expected for freshly initialized agents that have not called `POST /replicate`.
</ResponseField>

## curl Example

```bash theme={null}
curl -G https://ksrlmubaxzwufziwarps.supabase.co/functions/v1/v2-agent-state/head \
  -H "Authorization: Bearer sov_live_YOUR_KEY"
```