> ## 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)

> Verifies multi-factor authentication (MFA) using a one-time password (OTP).

`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](https://auth0.com/docs/mfa/guides/mfa-api/otp).

### Learn More

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

## Parameters

<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>

## Request Body

<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

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