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

# Verify Credentials

> Ensure that the credential is valid

Verification is a crucial step in the process of handling Verifiable Credentials. To ensure a credential is valid, the following checks are performed:

* Credential Structure: The credential should not be malformed. It must adhere to the correct structure as defined by the [credential type](/minting/verifiable-credentials/integrate/create-credential-types) .

* Signature Validation: The credential’s signature must be valid and match the identity of the issuer. This ensures that the credential was indeed issued by the claimed issuer and hasn’t been tampered with.

* Attribute Check: No additional attributes should have been added to the credential beyond what’s defined in its schema. This prevents unauthorized modifications to the credential.

* Expiration Check: The credential should not have expired. Credentials often have a validity period after which they are no longer considered valid.

* Revocation Check: The credential should not have been revoked by the issuer. Even if a credential is valid and hasn’t expired, it may have been revoked by the issuer for various reasons.

By performing these checks, we can ensure the authenticity and validity of a Verifiable Credential. Verifying a credential can happen either via the Crossmint API or SDK.

## API

To verify a credential on the server-side use the Crossmint API and the following endpoint, passing the [retrieved](/minting/verifiable-credentials/integrate/retrieve-credentials) unencrypted credential JSON.

<CodeGroup>
  ```javascript verifyCredential.js theme={null}
  const options = {
      method: "POST",
      headers: {
          "X-API-KEY": "YOUR_API_KEY",
          "Content-Type": "application/json",
      },
      body: `{"credential": ${JSON.stringify(credential.unencryptedCredential)}}`,
  };

  fetch("https://staging.crossmint.com/api/v1-alpha1/credentials/verification/verify", options)
      .then((response) => response.json())
      .then((response) => console.log(JSON.stringify(response)))
      .catch((err) => console.error(err));
  ```

  ```json Response theme={null}
  {
      "isValid": true
  }
  ```
</CodeGroup>

<Note> Verifying a credential via the API will require a Crossmint developer account.</Note>

## SDK

With the Verifiable Credentials client-side SDK, the verification process is performed locally, eliminating the need for interaction with Crossmint. Consequently, there is no need for a Crossmint developer account to verify the credential.

Install the `@crossmint/client-sdk-verifiable-credentials` [npm package](https://www.npmjs.com/package/@crossmint/client-sdk-verifiable-credentials) and call the `verifyCredential` function passing a `VerifiableCredential` object, as shown below.

<CodeGroup>
  ```typescript decrypt.ts theme={null}
  import * as sdk from '@crossmint/client-sdk-verifiable-credentials';

  sdk.CrossmintAPI.init('YOUR_API_KEY');

  const decryptedCredential = <CredentialObject>;

  const verificationResult = await sdk.verifyCredential(decryptedCredential);

  console.log('Verification result:', verificationResult);

  ```

  ```json Response theme={null}
  {
      "isValid": true
  }
  ```
</CodeGroup>

<Note>
  Verifying the status of the NFT related to the credential requires connection to the internet in order to access
  blockchain state.
</Note>

For details on the SDK functionality, review our [SDK reference documentation](/sdk-reference/credentials/introduction).

## Independent Verification

Since Crossmint’s Verifiable Credentials are based on the [W3C standard](https://www.w3.org/TR/vc-data-model-2.0/), you can use any library that supports this standard to verify a credential.

The W3C Verifiable Credentials standard ensures interoperability across different platforms and systems, enhancing the reliability and security of the credential verification process.

<Note>
  Crossmint verification is stricter and performs additional checks that are not part of the W3C standard. For example, that no additional fields have been added to the credential.
</Note>

<CardGroup cols={2}>
  <Card title="API Reference" icon="terminal" color="#B56710" href="/api-reference/verifiable-credentials/credentials/verify-credential">
    Test any API in seconds directly from the docs.
  </Card>

  <Card title="Talk to an expert" icon="message" iconType="duotone" color="#ADD8E6" href="https://www.crossmint.com/contact/sales">
    Contact our sales team for support.
  </Card>
</CardGroup>