> For the complete documentation index, see [llms.txt](https://gl-docs.gitbook.io/zkpass/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gl-docs.gitbook.io/zkpass/zkpass-developers-guide/zkpass-modules/dvr/dvr-client-roles/proof-verifier/2.-providing-proof-verification-api.md).

# 2. Providing Proof Verification API

## <mark style="color:blue;">Dvr Module Client Integration</mark>

In the proof verification API implementation, the Proof Verifier needs to verify the received ZkPass as shown here.

```typescript
import { DvrModuleClient, extractPayload } from "@zkpass/dvr-client-ts";

const dvrPayload = extractPayload(dvrToken);
...

// Step 1: Instantiate the zkPassClient object.
const dvrModuleClient = new DvrModuleClient({
      baseUrl: ZKPASS_SERVICE_URL,
      apiKey: API_KEY,
      secretApiKey: API_SECRET,
    });

// Step 2: Create the expected metadata
const expectedMetadata = {
      dvr: JSON.stringify(dvrPayload),
      ttl: EXPECTED_DVR_TTL,
      user_data_verifying_keys: userDataVerifyingKeys,
    };

// Step 3: Call zkPassClient.verifyZkPassProof to verify the proof.
const proofOutput = dvrModuleClient.callDvrVerifyZkPassProof(
      ZKPASS_ZKVM,
      zkPassProofToken,
      expectedMetadata
    );
```