Launch Configuration Properties Reference

Configure how Mule applications run and debug locally in Anypoint Code Builder by editing the launch.json file in your project’s .vscode folder.

Use launch.json configurations to:

Pass runtime arguments (encryption keys, environment variables, JVM properties)
Change the debug port to avoid conflicts when running multiple applications
Create multiple run profiles for different environments (Development, QA, Production)
Run multiple Mule applications concurrently in the same workspace
Test the same application with different property values without editing code

Configuration Properties Reference

This table lists some common properties for launch configurations.

Property Required Description

Property	Required	Description
`type`	Yes	Specifies the debugger type. Must be `"mule-xml-debugger"` for Mule applications or `"munit-xml-debugger"` for MUnit tests.
`request`	Yes	Specifies the launch type. Must be `"launch"` to start a new debug session.
`name`	Yes	Display name for this configuration. Appears in the Run and Debug view dropdown menu. Use descriptive names like `"Debug - Development"` or `"Run QA Environment"`.
`mule.project`	No	Path to a single Mule project. Use `"${workspaceFolder}"` for the current project. For multiple projects, use `mule.projects` instead. Either `mule.project` or `mule.projects` must be specified, but not both.
`mule.projects`	No	Array of project paths for running multiple Mule applications concurrently. Example: `["${workspaceFolder:project1}", "${workspaceFolder:project2}"]`. See Running Multiple Mule Applications Concurrently. Either `mule.project` or `mule.projects` must be specified, but not both.
`mule.home`	No	Path to the Mule runtime home directory. Use `"${config:mule.homeDirectory}"` to reference the configured Mule installation. Typically not needed as it defaults to the configured runtime.
`mule.runtime.args`	No	Command-line arguments passed to the Mule runtime JVM. Use the `-M-D` prefix for system properties and the `-M-X` prefix for JVM tuning flags. Examples: `-M-Dencryption.key=myKey` (encryption key) `-M-Denv=dev` (environment selector) `-M-Dhttp.port=8082` (HTTP listener port) `-M-Xmx2g` (maximum JVM heap size) `-M-Xms512m -M-Xmx2g` (initial and maximum JVM heap size) For more information, see Pass Runtime Properties and Arguments to Mule Applications and Defining and Securing Properties for a Mule Application.
`mule.debug.port`	No	Port number for the Mule debugger. Default: `6666`. Change this value when running multiple applications concurrently to avoid port conflicts. Example: `6667`, `6668`.
`noDebug`	No	Set to `true` to run the application without attaching the debugger. Useful for performance testing or when you don’t need breakpoint debugging. Default: `false`.

type

Yes

Specifies the debugger type. Must be "mule-xml-debugger" for Mule applications or "munit-xml-debugger" for MUnit tests.

request

Yes

Specifies the launch type. Must be "launch" to start a new debug session.

name

Yes

Display name for this configuration. Appears in the Run and Debug view dropdown menu. Use descriptive names like "Debug - Development" or "Run QA Environment".

mule.project

Path to a single Mule project. Use "${workspaceFolder}" for the current project. For multiple projects, use mule.projects instead.
Either mule.project or mule.projects must be specified, but not both.

mule.projects

Array of project paths for running multiple Mule applications concurrently. Example: ["${workspaceFolder:project1}", "${workspaceFolder:project2}"]. See Running Multiple Mule Applications Concurrently.
Either mule.project or mule.projects must be specified, but not both.

mule.home

Path to the Mule runtime home directory. Use "${config:mule.homeDirectory}" to reference the configured Mule installation. Typically not needed as it defaults to the configured runtime.

mule.runtime.args

Command-line arguments passed to the Mule runtime JVM. Use the -M-D prefix for system properties and the -M-X prefix for JVM tuning flags.

Examples:
-M-Dencryption.key=myKey (encryption key)
-M-Denv=dev (environment selector)
-M-Dhttp.port=8082 (HTTP listener port)
-M-Xmx2g (maximum JVM heap size)
-M-Xms512m -M-Xmx2g (initial and maximum JVM heap size)

For more information, see Pass Runtime Properties and Arguments to Mule Applications and Defining and Securing Properties for a Mule Application.

mule.debug.port

Port number for the Mule debugger. Default: 6666. Change this value when running multiple applications concurrently to avoid port conflicts. Example: 6667, 6668.

noDebug

Set to true to run the application without attaching the debugger. Useful for performance testing or when you don’t need breakpoint debugging. Default: false.

Either mule.project or mule.projects must be specified, but not both.

Creating Multiple Configuration Profiles

Create multiple launch configurations to test different environments without modifying your application code. Each configuration can have different runtime arguments, debug ports, and environment settings.

This example shows three configurations for Local Development, QA, and a Mocked environment:

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Debug - Local Dev",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments} -M-Denv=dev -M-Dencryption.key=devKey123",
      "mule.debug.port": 6666
    },
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Debug - QA Environment",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments} -M-Denv=qa -M-Dencryption.key=qaKey456",
      "mule.debug.port": 6667
    },
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Run - Mocked Services",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments} -M-Denv=mock -M-Dmock.services=true",
      "mule.debug.port": 6666,
      "noDebug": true
    }
  ]
}

Switch Between Configurations

To switch between run configurations:

Open the Run and Debug view from the activity bar ().
Click the configuration dropdown in the debug panel.
Select the configuration to use.

(for example, Debug - QA Environment).
Click Start () or press F5 to launch.

The selected configuration remains active until you select a different one.

Configuring the Debug Port

The default debug port for Anypoint Code Builder is 6666. Change this port when:

Running multiple Mule applications concurrently in the same workspace
The default port conflicts with another service on your system
Testing port-specific debugging scenarios

Change the Debug Port

Add or modify the mule.debug.port property in your launch configuration:

{
  "configurations": [
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Debug on Port 6667",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments}",
      "mule.debug.port": 6667
    }
  ]
}

Each concurrent application must use a unique debug port. For example, if running three applications simultaneously, configure them with ports 6666, 6667, and 6668.

Common Configuration Examples

These are some configuration examples for common scenarios.

Pass Encryption Keys for Secure Properties

{
  "configurations": [
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Debug with Encryption Key",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments} -M-Dencryption.key=mySecretKey"
    }
  ]
}

For more information, see Defining and Securing Properties for a Mule Application.

Switch Between Environment Property Files

{
  "configurations": [
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Development Environment",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments} -M-Denv=dev"
    },
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Production Environment",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments} -M-Denv=prod"
    }
  ]
}

This configuration works with property files named dev.secure.yaml and prod.secure.yaml that use the $site variable in your Mule configuration XML.

Run Multiple Applications Concurrently

{
  "configurations": [
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Run Multiple Apps",
      "noDebug": true,
      "mule.projects": [
        "${workspaceFolder:salesforce-integration}",
        "${workspaceFolder:database-service}",
        "${workspaceFolder:api-gateway}"
      ],
      "mule.runtime.args": "${config:mule.runtime.defaultArguments}"
    }
  ]
}

For more information, see Running Multiple Mule Applications Concurrently.

Use Environment Variables

Reference OS environment variables using the ${env:VARIABLE_NAME} syntax:

{
  "configurations": [
    {
      "type": "mule-xml-debugger",
      "request": "launch",
      "name": "Debug with Env Variables",
      "mule.project": "${workspaceFolder}",
      "mule.home": "${config:mule.homeDirectory}",
      "mule.runtime.args": "${config:mule.runtime.defaultArguments} -M-Dencryption.key=${env:MULE_ENCRYPTION_KEY} -M-Denv=${env:MULE_ENV}"
    }
  ]
}

Create or Open launch.json

To create or open the launch.json file:

Open the Command Palette.
Show me how
- Use the keyboard shortcuts:
  
  Mac: Cmd+Shift+p
  
  Windows: Ctrl+Shift+p
- Select View > Command Palette.
Enter and select Open 'launch.json'.

If the file doesn’t exist, Anypoint Code Builder creates it in the .vscode folder of your project.
Edit the configuration properties as needed.
Save the file.

The new or updated configuration appears in the Run and Debug view dropdown.