# Create an AnonCreds Credential Definition

## Register a Credential Definition

After registering a schema, a credential definition can be registered based on the schema. The credential definition, amongst more things, binds the schema to a specific issuer. Schemas can be reused between issuers, but a credential definition is specific to an issuer. In a credential definition revocation can also be specified. This section will not go in-depth about revocation.

{% code title="Issuer" %}

```typescript
const credentialDefinitionResult = await agent.modules.anoncreds.registerCredentialDefinition({
  credentialDefinition: {
    tag: 'default',
    issuerId: '<did>',
    schemaId: schemaResult.schemaState.schemaId,
  },
  options: {
    supportRevocation: false,
  },
})

if (credentialDefinitionResult.credentialDefinitionState.state === 'failed') {
  throw new Error(
    `Error creating credential definition: ${credentialDefinitionResult.credentialDefinitionState.reason}`
  )
}
```

{% endcode %}

The request body must contain the `credential_definition` object with the Issuer DID and the Schema ID created in the previous steps.

To enable revocation, the `options` must contain the revocation flag, and the size of the revocation registry. Also, ensure that a [Tails Server](https://github.com/bcgov/indy-tails-server) is configured for the issuer.

### Parameters

<details>

<summary>credential_definition (mandatory)</summary>

"issuerId": DID of the Issuer.

"schemaId": The AnonCreds Schema ID created by the Issuer (must be of the same DID).

"tag": Additional Name to identify the Credential Definition.

</details>

<details>

<summary>options (optional)</summary>

"support\_revocation": Boolean value to indicate that the Credential can be revoked or not. (Tails server must be configured if this is set to \`true\`)

"revocation\_registry\_size": Maximum size of the Revocation Registry.

</details>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.cheqd.io/product/sdk/credo/did-linked-resources/create-cred-def.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.