Build a Siddhi Application with the Graphical View

This tutorial walks you through building a simple Siddhi application visually using the Graphical View in WSO2 Integrator: SI. The application listens for production events over TCP, computes a running total of production amounts per product, and publishes the result to the console as JSON.

For full reference on every component, form field, and configuration available in the Graphical View, see Working with the Graphical View.

Open WSO2 Integrator: SI and create a new project

1. Open WSO2 Integrator. Open the command palette by pressing Ctrl + Shift + P (or Cmd + Shift + P on macOS), type WSO2 Integrator: Open Welcome Page, and select it.

2. On the welcome page, click Configure in the top right corner and select WSO2 Integrator: SI under Select your Integration Profile (if you have not already done so).

3. Create a new project. A new .siddhi file opens for you to work in.

   

4. To switch to the Graphical View, click the Open Graphical View button in the editor toolbar.

Define the input stream

To define the stream into which the events to be processed by the Siddhi application should be received, drag and drop the stream icon (shown below) onto the grid.

Once the stream component is added to the grid, move the cursor over it and click the settings icon as shown below.

The Stream Configuration form opens.

Fill the form as follows to define a stream named SweetProductionStream with two attributes named name and amount:

1. In the Name field, enter SweetProductionStream.

2. In the Attributes table, enter two attributes as follows. Click +Attribute to add a new row.

   Attribute Name	Attribute Type
   name	string
   amount	double

3. Click Submit to save the new stream definition. The stream is displayed on the grid with the SweetProductionStream label.

   

Define the output stream

Drag and drop the stream icon again to define the stream that the processed events will be directed to. Place it after the SweetProductionStream stream. Configure this stream as follows:

• Name: ProductionAlertStream

• Attributes:

  Attribute Name	Attribute Type
  name	string
  totalProduction	long

Add the source

To add the source from which events are received, drag and drop the source icon (shown below) onto the grid. The source is an input to the SweetProductionStream input stream component, so place this source component to the left of the input stream component.

Once you add the source component, draw a line from it to the SweetProductionStream input stream component by dragging the cursor as demonstrated below.

Click the settings icon on the source component to open the Source Configuration form. Then enter information as follows:

1. In the Source Type field, select tcp.
2. In this example, events are received in the binary format. To indicate that events are expected to be converted from this format, select binary in the Map Type field.
3. To indicate the context, select the context check box and enter SweetProductionData in the field that appears below.
4. Click Submit.

Add the projection query

To add a query that defines the execution logic, drag and drop the projection query icon (shown below) onto the grid.

The query uses the events in the SweetProductionStream input stream as inputs and directs the processed events to the ProductionAlertStream output stream. Create two connections as demonstrated below.

To define the execution logic, move the cursor over the query in the grid, click the settings icon, and configure as follows:

1. Enter a name for the query in the Name field. Use query.
2. To specify how each input stream attribute is converted to generate the output events, select User Defined Attributes in the Select field. The User Defined Attributes table appears, with the As column listing the output stream attributes. Enter expressions in the Expression column:
   1. The value for name can be derived from the input stream without any further processing. Enter name as the expression.
   2. To derive the value for totalProduction, the values for amount need to be summed. Enter sum(amount) as the expression.
   3. Leave the default values of the Output section unchanged.
3. Click Submit.

Add the sink

To add a sink that publishes the output events directed to the ProductionAlertStream output stream, drag and drop the sink icon (shown below) onto the grid.

Draw an arrow from the ProductionAlertStream output stream to the sink component to connect them.

Click the settings icon on the sink component to open the Sink Configuration form. Then:

1. To publish output as logs in the console, select log in the Sink Type field.
2. In the Map Type field, select the format. For this example, select json.
3. Click Submit.

Save the Siddhi application

Click Show Source to switch back to the Source View. The Siddhi application is displayed as follows.

To save this Siddhi application, click File → Save.

What's Next?

• For full reference on every Graphical View component and form, see Working with the Graphical View.
• To run and test your Siddhi application, see Running and Testing Siddhi Applications.

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Last update: May 14, 2026