Skip to main content

Example

HTTP Example​

What you'll build​

Build an HTTP GET integration using the ballerina/http HTTP Client connector in WSO2 Integrator's visual designer. The integration sends an outbound GET request to a configurable URL and captures the HTTP response. The flow runs as an Automation entry point named main.

Operations used:

  • get: Sends an HTTP GET request to a specified path and returns the HTTP response.

Architecture​

Setting up the HTTP integration​

New to WSO2 Integrator? Follow the Create a New Integration guide to set up your integration first, then return here to add the connector.

Adding the HTTP connector​

Select + Add Connection in the Connections section of the WSO2 Integrator sidebar to open the connector palette.

HTTP connector palette open with search field before any selection

Configuring the HTTP connection​

Step 1: Fill in connection parameters​

In the New Connection form, bind the connection parameters to configurable variables:

  • connectionName: Set to httpClient as the name for this connection
  • url: Bind to a new configurable variable named httpServiceUrl (type: string) using the variable binding icon

HTTP connection form fully filled with all parameters before saving

Step 2: Save the connection​

Select Save to create the connection. The connection httpClient now appears under Connections in the WSO2 Integrator sidebar.

HTTP Connections panel showing httpClient entry after saving

Step 3: Set actual values for your configurables​

  1. In the left panel, select Configurations.
  2. Set a value for each configurable listed below.
  • httpServiceUrl (string): The base URL of the HTTP service to send GET requests to (for example, https://your-target-api.com)

Configuring the HTTP get operation​

Step 4: Add an Automation entry point​

  1. In the WSO2 Integrator sidebar, hover over Entry Points and select +.
  2. Select Automation from the entry point types.

An Automation entry point named main is created and the visual designer opens, showing Start → (empty node placeholder) → Error Handler.

Step 5: Select the get operation and configure its parameters​

  1. Select the empty placeholder node on the canvas to open the node panel.
  2. Expand the httpClient connection and select get from the list of available operations.
  3. Fill in the operation parameters:
  • path: Enter / as the request path
  • result: Set the result variable name to result
  • targetType: Enter http:Response as the expected response type

HTTP get operation configuration filled with all values

Completed HTTP automation flow

Try it yourself​

Try this sample in WSO2 Integration Platform.

Deploy to Devant

View source on GitHub

HTTP Trigger Example​

What you'll build​

An HTTP Service integration listens for incoming HTTP requests on a configurable port using the ballerina/http trigger from the Integration as API category. When an HTTP client sends a GET /messages request to the listener, the trigger routes it to the resource handler, which builds a JSON payload and logs it as a JSON string using log:printInfo. The complete flow: HTTP listener → resource handler → log:printInfo → response is assembled visually on the WSO2 Integrator visual designer.

Architecture​

Prerequisites​

  • An HTTP client tool for sending test requests (for example, curl, Postman, or a browser) capable of sending GET requests to the configured HTTP Service endpoint.

Setting up the HTTP Service integration​

New to WSO2 Integrator? Follow the Create a New Integration guide to set up your integration first, then return here to add the trigger.

Adding the HTTP Service trigger​

Step 1: Open the Artifacts palette and select the HTTP Service trigger​

  1. Select + Add Artifact on the canvas to open the Artifacts palette.
  2. In the Integration as API category, locate and select the HTTP Service card.

Artifacts palette open showing the Integration as API category with the HTTP Service card visible

Configuring the HTTP Service listener​

Step 2: Bind HTTP listener parameters to configuration variables​

In the Create HTTP Service form, expand Advanced Configurations and select Custom Listener to expose the listener parameters. For the listener port, switch the field to Expression mode, open the Helper Panel, select the Configurables tab, select + New Configurable, enter a camelCase variable name and int as the type, leave the default value blank, and select Save. The variable is automatically injected into the port field. Enum/dropdown options such as the Service Contract radio group and boolean-style toggles are set directly from the UI and don't need configurable bindings.

  • Port: The TCP port the HTTP listener binds to; bound to a configurable int variable so the port can be set at runtime without modifying the integration source.
  • Listener Name: The identifier used for the http:Listener variable in the generated source; kept as httpListener.

HTTP Service trigger configuration form with the Port field bound to the httpListenerPort configuration variable, before selecting Create

Step 3: Set actual values for your configurations​

  1. In the left panel of WSO2 Integrator, select Configurations (at the bottom of the project tree, under Data Mappers).
  2. Set a value for each configuration listed below.
  • httpListenerPort (int): The actual TCP port number the HTTP listener should bind to at runtime (for example, 8090).

Configurable Variables panel open showing the httpListenerPort variable listed with an empty Required value field

Step 4: Select Create to register the listener and open the Service view​

Select Create at the bottom of the trigger configuration form. WSO2 Integrator registers the HTTP listener (httpListener) under Listeners and opens the HTTP Service view, where you can add resource function handlers.

Handling HTTP Service events​

Step 5: Open the Add Handler side panel​

  1. In the HTTP Service view, locate the Resources section.
  2. Select + Add Resource on the right of the section header. The Select HTTP Method to Add side panel opens, listing the available HTTP methods (GET, POST, PUT, DELETE, PATCH, DEFAULT).

HTTP Service view with the Select HTTP Method to Add side panel open listing available resource handler options

Step 6: Select the primary resource handler and define the message payload type​

  1. In the Select HTTP Method to Add side panel, select GET. The New Resource Configuration panel replaces the method list.
  2. In the Resource Path field, enter messages to expose the handler at GET /messages.
  3. Review the default Responses rows: 200 returns a json body and 500 returns an error. Leave both as-is for this sample.
  4. Optionally add path params, query parameters, or headers using the + Path Param, + Query Parameter, and + Header links if your handler needs them.
  5. Select Save to register the resource.

Define Value modal on the Create Type Schema tab showing the record name and fields filled in before Save

Step 7: Save the handler and add a log statement to the flow​

  1. After selecting Save on the New Resource Configuration panel, the flow canvas for the resource handler opens.
  2. Locate the primary resource function body (resource function get messages()) in the flow.
  3. Add a JSON payload declaration followed by log:printInfo(payload.toJsonString()); inside the handler body.
  4. Confirm the canvas renders Start → Declare Variable (payload) → log:printInfo → Return → Error Handler → End, confirming the log step is wired into the flow.

Handler flow canvas showing the Declare Variable, log, Return, and Error Handler nodes between Start and End

Step 8: Confirm the handler is registered in the Service view​

Select the back arrow in the canvas header (or re-select the HTTP Service entry in the left project tree) to return to the HTTP Service view. The Resources list now shows the registered GET /messages resource handler row.

Final HTTP Service view showing the registered GET messages resource row in the Resources section

Running the integration​

Step 9: Run the integration and send a test HTTP request​

  1. In the WSO2 Integrator panel, select Run to start the integration. Wait for the listener to bind to the configured port (watch the output for a "started HTTP/WS listener" message).
  2. Send a test HTTP request using one of the following options:
    • A separate WSO2 Integrator HTTP Client integration assembled from the same visual designer (recommended, no external tooling required).
    • The curl command-line tool: send a GET request to the configured endpoint using curl -X GET http://<host>:<httpListenerPort>/messages, replacing <host> and <httpListenerPort> with the values you set in the Configurations panel.
    • A GUI HTTP client such as Postman or Insomnia: send a GET request to the configured endpoint.
  3. Observe the integration's log output. The payload JSON string (for example, {"message":"Hello from HTTP listener","path":"/messages"}) should appear printed by log:printInfo, confirming the handler received and processed the incoming HTTP request.

Try it yourself​

Try this sample in WSO2 Integration Platform.

Deploy to Devant

View source on GitHub

More code examples​

The HTTP connector provides practical examples illustrating usage in various scenarios. Explore these examples, covering HTTP services, clients, security, REST API design, and streaming use cases.

  1. Ballerina Secure Token Service (STS): Implement a secure token service that demonstrates HTTP service security and token-based access flows.

  2. Pet Clinic REST API: Build a REST API for a pet clinic application using HTTP services, resources, and data persistence.

  3. Server-sent events: Explore server-sent event examples for streaming updates from an HTTP service to clients.

  4. Snowpeak REST API: Learn REST API design patterns using an HTTP service and client implementation.