> ## 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.

# FlowX.AI Scheduler

> The Scheduler is part of the core extensions of the FlowX.AI platform. You can add it to your custom FlowX deployment to enhance the core platform capabilities with functionality specific to scheduling messages.

The service offers the possibility to schedule a message that you only need to process after a configured time period.

It can be quickly deployed on the chosen infrastructure and then connected to the **FlowX.AI Engine** through Kafka events.

## Using the scheduler

After deploying the scheduler service in your infrastructure, you can start using it to schedule messages that you need to process at a later time.

One such example would be to use the scheduler service to expire processes that were started but haven't been finished.

<Warning>
  First you need to check the configured Kafka topics match the ones configured in the engine deployment.
</Warning>

<Check>
  For example the engine topics `KAFKA_TOPIC_PROCESS_SCHEDULE_OUT_SET` and `KAFKA_TOPIC_PROCESS_SCHEDULE_OUT_STOP` **must** be the same with the ones configured in the scheduler at `KAFKA_TOPIC_SCHEDULE_IN_SET` and `KAFKA_TOPIC_SCHEDULE_IN_STOP` environment variables.
</Check>

When a process is scheduled to expire, the engine sends the following message to the scheduler service (on the topic `KAFKA_TOPIC_SCHEDULE_IN_SET`):

```json theme={"system"}
{
  "applicationName": "onboarding",
  "applicationId": "04f82408-ee66-4c68-8162-b693b06bba00",
  "payload": {
    "scheduledEventType": "EXPIRE_PROCESS",
    "processInstanceUuid": "04f82408-ee66-4c68-8162-b693b06bba00"
  },
  "scheduledTime": 1621412209.353327,
  "responseTopicName": "ai.flowx.process.expire.staging"
}
```

The scheduled time should be defined as `java.time.Instant`.

At the scheduled time, the payload will be sent back to the response topic defined in the message, like so:

```json theme={"system"}
{
  "scheduledEventType": "EXPIRE_PROCESS",
  "processInstanceUuid": "04f82408-ee66-4c68-8162-b693b06bba00"
}
```

If you don't need the scheduled message anymore, you can discard it by sending the following message (on the topic `KAFKA_TOPIC_SCHEDULE_IN_STOP`)

```json theme={"system"}
{
  "applicationName": "onboarding",
  "applicationId": "04f82408-ee66-4c68-8162-b693b06bba00"
}
```

These fields, `applicationName` and `applicationId` are used to uniquely identify a scheduled message.

<Card title="Scheduler setup" href="../../../setup-guides/scheduler-setup-guide" icon="gears">
  Steps to deploy and set up the service
</Card>