> ## 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.

# Start/end nodes

> Let's go through all the options for configuring start and end nodes for a process definition.

## Start node

The start node represents the beginning of a process and it is mandatory to add one when creating a process.

<Frame>
  ![Start node](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/building-blocks/node/start_node.png#center)
</Frame>

A process can have one or more start nodes. If you defined multiple start nodes, each should have a start condition value configured. When starting a new process instance the desired start condition should be used.

![](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/building-blocks/node/start_node_example.png)

### Configuring a start node

Node configuration is done by accessing the **Node Config** tab. You have the following configuration options for a **start node**:

* [General Config](#general-config)
* [Start condition](#start-condition)

#### General Config

* **Node name** - the name of the node
* **Can go back** - switching this option to true will allow users to return to this step after completing it

<Info>
  When encountering a step with `canGoBack` switched to false, all steps found behind it will become unavailable.
</Info>

* [**Swimlane**](../../platform-deep-dive/user-roles-management/swimlanes) - choose a swimlane (if there are multiple swimlanes on the process) to make sure only certain user roles have access to certain process nodes- if there are no multiple swimlanes, the value is **Default**
* [**Stage**](../../platform-deep-dive/core-extensions/task-management/using-stages)- assign a stage to the node

#### Start condition

The start condition should be set as a string value. This string value will need to be set on the payload for the start process request on the `startCondition` key.

<Frame>
  ![](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/building-blocks/node/start_node_condition.png)
</Frame>

To test the start condition, we can send a start request via REST:

```
POST {{processUrl}}/api/process/{{processName}}/start
{
    "startCondition": "PF"
}
```

#### Error handling on start condition

If a request is made to start a process with a start condition that does not match any start node, an error will be generated. Let's take the previous example and assume we send an incorrect value for the start condition:

```
POST {{processUrl}}/api/process/{{processName}}/start
{
    "startCondition": "PJ"
}
```

A response with the error code `bad request` and title `Start node for process definition not found`will be sent in this case:

```json theme={"system"}
{
    "entityName": "ai.flowx.process.definition.domain.NodeDefinition",
    "defaultMessage": "Start node for process definition not found.",
    "errorKey": "error.validation.process_instance.start_node_for_process_def_missing",
    "type": "https://www.jhipster.tech/problem/problem-with-message",
    "title": "Start node for process definition not found.",
    "status": 400,
    "message": "error.validation.process_instance.start_node_for_process_def_missing",
    "params": "ai.flowx.process.definition.domain.NodeDefinition"
}
```

## End node

<Frame>
  ![End Event](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/building-blocks/node/end-event.png#center)
</Frame>

An end node is used to mark where the process finishes. When the process reaches this node, the process is considered completed and its status will be set to `Finished`.

### Configuring an end node

Multiple end nodes can be used to show different end states. The configuration is similar to the start node.

![End node](https://s3.eu-west-1.amazonaws.com/docx.flowx.ai/building-blocks/node/end_node.png)