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

# Verify Chain

> Validate the integrity of your workspace's hash chain.

## GET /api/v1/verify

Verify the SHA-256 hash chain for your workspace. Returns whether the chain is intact and details of any breaks detected.

### Query Parameters

<ParamField query="from" type="string">
  ISO 8601 timestamp. Verify events from this time onward.
</ParamField>

<ParamField query="to" type="string">
  ISO 8601 timestamp. Verify events up to this time.
</ParamField>

<ParamField query="limit" type="integer" default="10000">
  Maximum number of events to verify.
</ParamField>

### Response (Valid Chain)

```json theme={null}
{
  "data": {
    "valid": true,
    "events_checked": 4821,
    "breaks": []
  }
}
```

### Response (Tampered Chain)

```json theme={null}
{
  "data": {
    "valid": false,
    "events_checked": 4821,
    "breaks": [
      {
        "event_id": "9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d",
        "type": "hash_mismatch",
        "expected_hash": "a3f2c8d1e4b567890abcdef...",
        "actual_hash": "ff00ab12cd34ef5678901234..."
      },
      {
        "event_id": "c4d5e6f7-8a9b-0c1d-2e3f-4a5b6c7d8e9f",
        "type": "chain_break",
        "expected_hash": "7b9e1d3f5a2c67890abcdef...",
        "actual_hash": "0000000000000000000000..."
      }
    ]
  }
}
```

### Break Types

<ResponseField name="hash_mismatch">
  The stored hash does not match the recomputed hash. Indicates the event data has been modified after ingestion.
</ResponseField>

<ResponseField name="chain_break">
  The `previous_event_hash` on an event does not match the hash of the preceding event. Indicates an event was inserted into or deleted from the chain.
</ResponseField>

### Examples

<CodeGroup>
  ```bash cURL -- Full verification theme={null}
  curl https://getimmutable.dev/api/v1/verify \
    -H "Authorization: Bearer imk_your_api_key_here"
  ```

  ```bash cURL -- Date range theme={null}
  curl "https://getimmutable.dev/api/v1/verify?from=2026-03-01T00:00:00Z&to=2026-03-31T23:59:59Z" \
    -H "Authorization: Bearer imk_your_api_key_here"
  ```

  ```typescript JavaScript theme={null}
  // Full chain
  const result = await client.verify();

  // Date range
  const ranged = await client.verify(
    "2026-03-01T00:00:00Z",
    "2026-03-31T23:59:59Z"
  );
  ```

  ```php Laravel theme={null}
  $result = AuditLog::verify();

  $ranged = AuditLog::verify(
      '2026-03-01T00:00:00Z',
      '2026-03-31T23:59:59Z'
  );
  ```
</CodeGroup>

<Note>
  Legacy events ingested before hash chain activation have nullable hash fields. These events are skipped during verification and do not produce breaks.
</Note>