> ## Documentation Index
> Fetch the complete documentation index at: https://docs-dev-docs-event-stream-action-templates.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Verify multi-factor authentication with one-time password (OTP)

> Verify MFA using a one-time password (OTP) to complete the token request.

export const ResponseSchema = ({statusCode, type = "{}", children}) => {
  const [open, setOpen] = useState(false);
  return <div className="border border-gray-100 dark:border-gray-800 rounded-lg mb-3 overflow-hidden">
      <div className={`flex items-center gap-2.5 px-4 py-2.5 cursor-pointer select-none ${open ? "bg-gray-50 dark:bg-gray-800" : ""}`} onClick={() => setOpen(!open)}>
        {statusCode && <span className="border border-gray-300 dark:border-gray-600 text-gray-700 dark:text-gray-300 font-mono text-xs px-1.5 py-0.5 rounded">
            {statusCode.startsWith("default") ? "default" : statusCode}
          </span>}
        <span className="text-gray-500 dark:text-gray-400 text-sm font-mono">
          {type}
        </span>
        <span className="text-gray-400 dark:text-gray-500 text-sm italic">
          application/json
        </span>
        <svg className={`ml-auto opacity-50 transition-transform duration-200 ${open ? "rotate-180" : ""}`} width="16" height="16" viewBox="0 0 16 16" fill="none">
          <path d="M4 6l4 4 4-4" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round" />
        </svg>
      </div>
      {open && <div className="px-4 pt-1 pb-3 border-t border-gray-100 dark:border-gray-800">
          {children}
        </div>}
    </div>;
};

## Endpoint

`POST /oauth/token`

Verifies multi-factor authentication (MFA) using a one-time password (OTP). To verify MFA with an OTP, prompt the user to get the OTP code, then make a request to the /oauth/token endpoint. The request must have the OTP code, the mfa\_token you received (from the mfa\_required error), and the grant\_type set to [http://auth0.com/oauth/grant-type/mfa-otp](http://auth0.com/oauth/grant-type/mfa-otp). The response is the same as responses for password or [http://auth0.com/oauth/grant-type/password-realm](http://auth0.com/oauth/grant-type/password-realm) grant types. Learn more at [Associate OTP Authenticators](/mfa/guides/mfa-api/otp).

### Learn More

* [Associate OTP Authenticators](https://auth0.com/docs/mfa/guides/mfa-api/otp)

## Headers

<ParamField header="DPoP" type="string">
  A DPoP proof for the request. This is optional and only required if your application uses Demonstrating Proof-of-Possession.
</ParamField>

## Body Parameters

<ParamField body="grant_type" type="string" required>
  Denotes the flow you are using. For OTP MFA use `http://auth0.com/oauth/grant-type/mfa-otp`.
</ParamField>

<ParamField body="client_id" type="string">
  Your application's Client ID.
</ParamField>

<ParamField body="client_secret" type="string">
  Your application's Client Secret.
</ParamField>

<ParamField body="mfa_token" type="string" required>
  The `mfa_token` you received from `mfa_required` error.
</ParamField>

<ParamField body="otp" type="string" required>
  OTP Code provided by the user.
</ParamField>

<ParamField body="client_assertion" type="string">
  A JWT containing a signed assertion with your application credentials.
</ParamField>

<ParamField body="client_assertion_type" type="string">
  The value is `urn:ietf:params:oauth:client-assertion-type:jwt-bearer`.
</ParamField>

## Response Schema

<ResponseSchema>
  <ResponseField name="access_token" type="string">
    The access token for the authenticated session.
  </ResponseField>

  <ResponseField name="token_type" type="string">
    The type of token issued.
  </ResponseField>

  <ResponseField name="expires_in" type="integer">
    The access token lifetime in seconds.
  </ResponseField>
</ResponseSchema>

## Response Messages

| Status | Description                                                 |
| ------ | ----------------------------------------------------------- |
| 200    | OTP verification successful.                                |
| 400    | Invalid request, such as missing parameters or invalid OTP. |