> ## 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 Anchor

> Verify an anchor's Merkle root integrity and anchor chain validity.

## GET /api/v1/anchors/{id}/verify

Recomputes the Merkle root from the underlying events and checks that it matches the stored anchor. Also validates the anchor chain by verifying `previous_anchor_hash` references the preceding anchor correctly.

### Path Parameters

<ParamField path="id" type="string" required>
  The anchor identifier (e.g., `anc_abc123`).
</ParamField>

### Response

```json theme={null}
{
  "data": {
    "anchor_id": "anc_abc123",
    "merkle_root": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
    "valid": true,
    "chain_valid": true,
    "expected": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
    "actual": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
    "events_count": 1247,
    "tx_hash": "0x7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b",
    "explorer_url": "https://basescan.org/tx/0x7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b"
  }
}
```

### Response Fields

<ResponseField name="anchor_id" type="string">
  The anchor identifier.
</ResponseField>

<ResponseField name="merkle_root" type="string">
  The 64-character hex Merkle root stored in this anchor record.
</ResponseField>

<ResponseField name="valid" type="boolean">
  `true` if the Merkle root recomputed from the underlying events matches the stored `merkle_root`. `false` if the events have been modified, inserted, or deleted since the anchor was created.
</ResponseField>

<ResponseField name="chain_valid" type="boolean">
  `true` if the `previous_anchor_hash` correctly equals `SHA-256(previous_merkle_root + previous_tx_hash)`. `false` if the anchor chain has been tampered with. Always `true` for the first anchor in a workspace.
</ResponseField>

<ResponseField name="expected" type="string">
  The Merkle root recomputed from the current event data. If `valid` is `true`, this matches `actual`.
</ResponseField>

<ResponseField name="actual" type="string">
  The Merkle root stored in the anchor record at creation time. If `valid` is `true`, this matches `expected`.
</ResponseField>

<ResponseField name="events_count" type="integer">
  The number of events included in this anchor's Merkle tree.
</ResponseField>

<ResponseField name="tx_hash" type="string">
  The blockchain transaction hash. Null if the anchor is not yet confirmed on-chain.
</ResponseField>

<ResponseField name="explorer_url" type="string">
  Direct link to the transaction on Basescan. Null if not yet confirmed.
</ResponseField>

### Examples

<CodeGroup>
  ```bash cURL theme={null}
  curl https://getimmutable.dev/api/v1/anchors/anc_abc123/verify \
    -H "Authorization: Bearer imk_your_api_key_here"
  ```

  ```typescript JavaScript theme={null}
  import { ImmutableClient } from "getimmutable";

  const client = new ImmutableClient({
    apiKey: "imk_your_api_key_here",
    baseUrl: "https://getimmutable.dev",
  });

  const result = await client.verifyAnchor("anc_abc123");

  if (result.data.valid && result.data.chain_valid) {
    console.log("Anchor verified successfully.");
    console.log(`${result.data.events_count} events, Merkle root intact.`);
    console.log(`Explorer: ${result.data.explorer_url}`);
  } else {
    if (!result.data.valid) {
      console.error("Merkle root mismatch!");
      console.error(`Expected: ${result.data.expected}`);
      console.error(`Actual:   ${result.data.actual}`);
    }
    if (!result.data.chain_valid) {
      console.error("Anchor chain integrity violation!");
    }
  }
  ```

  ```python Python theme={null}
  from getimmutable import ImmutableClient

  client = ImmutableClient(
      api_key="imk_your_api_key_here",
      base_url="https://getimmutable.dev",
  )

  result = client.verify_anchor("anc_abc123")

  if result["data"]["valid"] and result["data"]["chain_valid"]:
      print(f"Anchor verified. {result['data']['events_count']} events.")
  else:
      if not result["data"]["valid"]:
          print(f"Merkle root mismatch: expected {result['data']['expected']}, got {result['data']['actual']}")
      if not result["data"]["chain_valid"]:
          print("Anchor chain integrity violation")
  ```

  ```php Laravel theme={null}
  use GetImmutable\AuditLog;

  $result = AuditLog::client()->verifyAnchor('anc_abc123');

  if ($result['data']['valid'] && $result['data']['chain_valid']) {
      Log::info('Anchor verified', [
          'events' => $result['data']['events_count'],
          'explorer' => $result['data']['explorer_url'],
      ]);
  } else {
      Log::critical('Anchor verification failed', $result['data']);
  }
  ```
</CodeGroup>

### Interpreting Results

| `valid` | `chain_valid` | Meaning                                                                                                        |
| ------- | ------------- | -------------------------------------------------------------------------------------------------------------- |
| `true`  | `true`        | Everything is intact. Merkle root matches events, anchor chain is correct.                                     |
| `false` | `true`        | Events were modified after this anchor was created. The anchor chain is fine, but the underlying data changed. |
| `true`  | `false`       | Events are intact, but a preceding anchor was modified or deleted.                                             |
| `false` | `false`       | Both the events and the anchor chain have been tampered with.                                                  |

<Warning>
  Anchors with `status: "pending"` or `status: "submitted"` will have null `tx_hash` and `explorer_url`. The `valid` and `chain_valid` checks still run against the stored Merkle root and anchor chain, but on-chain cross-verification is not possible until the anchor reaches `confirmed` status.
</Warning>

<Tip>
  After verifying via the API, cross-check the `tx_hash` on Basescan for fully independent verification. See [Verify On-Chain](/trust/verify-on-chain) for a step-by-step guide.
</Tip>