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

# Generate OTP

> There are some cases when you will need to generate an OTP (One Time Password) from a business flow, for example when validating an email account.

The notifications plugin handles both the actual OTP code generation and sending the code to the user using a defined [notification template](../managing-notification-templates).

![](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/platform-deep-dive/otp_archi.png)

## Define needed Kafka topics

<Info>
  **DEVELOPER**: Kafka topic names can be set/found by using the following environment variables in your Notifications plugin deployment:

  * `KAFKA_TOPIC_OTP_GENERATE_IN`
  * `KAFKA_TOPIC_OTP_GENERATE_OUT` - after the OTP is generated and sent to the user, this is the topic used to send the response back to the Engine.
</Info>

<Info>
  The Engine is listening for messages on topics with names of a certain pattern, make sure to use an outgoing topic name that matches the pattern configured in the Engine.
</Info>

## Request to generate an OTP

Values expected in the request body:

* **templateName**: the name of the notification template that is used (created using the [WYSIWYG](../../../wysiwyg) editor)
* **channe**l: notification channel (SMS / MAIL)
* **recipient**: notification receiver: email / phone number
* **notification template content parameters (for example, clientId)**: parameters that should be replaced in the [notification template](../managing-notification-templates)

<Frame>
  ![](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/platform-deep-dive/notifications_params.png)
</Frame>

## Response from generate OTP

Values expected in the reply body:

* **processInstanceId** = process instance ID
* **clientId** = the client id (in this case the SSN number of the client)
* **channel** = notification channel used
* **otpSent** = confirmation if the notification was sent: true or false
* **error** = error description, if any

**Example:**

![](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/platform-deep-dive/otp_response.png)

## Example: generate an OTP from a business flow

Identify the business identifier you will use to validate the OTP (for example, a user identification number).

1. Configure the templates that you want to use (for example, an SMS template).
2. Make sure the Kafka communication through (`KAFKA_TOPIC_OTP_GENERATE_IN` topic - send the otp request) and the topic used to receive the response (`KAFKA_TOPIC_OTP_GENERATE_OUT`) is defined properly.

<Tip>
  You can check the defined topics by going to **FlowX Designer > Platform Status > notification-plugin-mngt > kafkaTopicsHealthCheckIndicator > details > configuration > topic > otp**.
</Tip>

3. Use the FlowX Designer to add a new **Kafka send event** to the correct node in the process definition.
4. Add the proper configuration to the action, the Kafka topic, and configure the body message.

<Frame>
  ![](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/platform-deep-dive/kafka_config_otp.png)
</Frame>

5. Add a node to the process definition (for the Kafka receive event).
6. Configure on what key you want to receive the response on the process instance params.

<Frame>
  ![](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/platform-deep-dive/otp_config1.png)
</Frame>