system_launch_app

Launch macOS applications by name using AppleScript automation through the MCP server.

Instructions

[System control and information] Launch an application

Input Schema

TableJSON Schema

Name	Required	Description	Default
`name`	Yes	Application name

Implementation Reference

src/categories/system.ts:37-60 (handler)

Handler implementation for the 'system_launch_app' tool. This defines the AppleScript template that launches or activates the specified application by name, handling errors.

{
  name: "launch_app",
  description: "Launch an application",
  schema: {
    type: "object",
    properties: {
      name: {
        type: "string",
        description: "Application name",
      },
    },
    required: ["name"],
  },
  script: (args) => `
        try
          tell application "${args.name}"
            activate
          end tell
          return "Application ${args.name} launched successfully"
        on error errMsg
          return "Failed to launch application: " & errMsg
        end try
      `,
},

src/categories/system.ts:40-49 (schema)

Input schema for 'system_launch_app' tool, requiring the application 'name' as a string.

schema: {
  type: "object",
  properties: {
    name: {
      type: "string",
      description: "Application name",
    },
  },
  required: ["name"],
},

src/index.ts:25-25 (registration)
Registration of the 'system' category, which includes the 'launch_app' script that becomes the 'system_launch_app' tool.
```
server.addCategory(systemCategory);
```

src/framework.ts:221-232 (registration)

Tool registration in listTools handler, constructing tool name as 'category_script' e.g. 'system_launch_app'.

this.server.setRequestHandler(ListToolsRequestSchema, async () => ({
  tools: this.categories.flatMap((category) =>
    category.scripts.map((script) => ({
      name: `${category.name}_${script.name}`, // Changed from dot to underscore
      description: `[${category.description}] ${script.description}`,
      inputSchema: script.schema || {
        type: "object",
        properties: {},
      },
    })),
  ),
}));

src/framework.ts:235-281 (handler)

Core execution handler for all tools including 'system_launch_app'. Parses tool name by splitting on '_', retrieves category/script, generates script content, and executes it via osascript.

this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
  const toolName = request.params.name;
  this.log("info", "Tool execution requested", { 
    tool: toolName,
    hasArguments: !!request.params.arguments
  });
  
  try {
    // Split on underscore instead of dot
    const [categoryName, ...scriptNameParts] =
      toolName.split("_");
    const scriptName = scriptNameParts.join("_"); // Rejoin in case script name has underscores

    const category = this.categories.find((c) => c.name === categoryName);
    if (!category) {
      this.log("warning", "Category not found", { categoryName });
      throw new McpError(
        ErrorCode.MethodNotFound,
        `Category not found: ${categoryName}`,
      );
    }

    const script = category.scripts.find((s) => s.name === scriptName);
    if (!script) {
      this.log("warning", "Script not found", { 
        categoryName, 
        scriptName 
      });
      throw new McpError(
        ErrorCode.MethodNotFound,
        `Script not found: ${scriptName}`,
      );
    }

    this.log("debug", "Generating script content", { 
      categoryName, 
      scriptName,
      isFunction: typeof script.script === "function"
    });
    
    const scriptContent =
      typeof script.script === "function"
        ? script.script(request.params.arguments)
        : script.script;

    const result = await this.executeScript(scriptContent);

applescript-mcp