add-nodebridge-handler

Overview

This skill guides the process of adding a new message handler to the NodeBridge system, which enables communication between the UI layer and the Node.js backend.

Steps

1. Add Handler Implementation in src/nodeBridge.ts

Locate the registerHandlers() method in the NodeHandlerRegistry class and add your handler:

this.messageBus.registerHandler('category.handlerName', async (data) => {
  const { cwd, ...otherParams } = data;
  const context = await this.getContext(cwd);
  
  // Implementation logic here
  
  return {
    success: true,
    data: {
      // Return data
    },
  };
});

Handler Naming Convention:

• Use dot notation: category.action (e.g., git.status, session.send, utils.getPaths)
• Categories: config, git, mcp, models, outputStyles, project, projects, providers, session, sessions, slashCommand, status, utils

Common Patterns:

• Always get context via await this.getContext(cwd)
• Return { success: true, data: {...} } for success
• Return { success: false, error: 'message' } for errors
• Wrap in try/catch for error handling

2. Add Type Definitions in src/nodeBridge.types.ts

Add input and output types near the relevant section:

// ============================================================================
// Category Handlers
// ============================================================================

type CategoryHandlerNameInput = {
  cwd: string;
  // other required params
  optionalParam?: string;
};

type CategoryHandlerNameOutput = {
  success: boolean;
  error?: string;
  data?: {
    // return data shape
  };
};

Then add to the HandlerMap type:

export type HandlerMap = {
  // ... existing handlers
  
  // Category handlers
  'category.handlerName': {
    input: CategoryHandlerNameInput;
    output: CategoryHandlerNameOutput;
  };
};

3. (Optional) Add to Test Script

Update scripts/test-nodebridge.ts HANDLERS object if the handler should be easily testable:

const HANDLERS: Record<string, string> = {
  // ... existing handlers
  'category.handlerName': 'Description of what this handler does',
};

4. Test the Handler

Run the test script:

bun scripts/test-nodebridge.ts category.handlerName --cwd=/path/to/dir --param=value

Or with JSON data:

bun scripts/test-nodebridge.ts category.handlerName --data='{"cwd":"/path","param":"value"}'

Example: Complete Handler Addition

nodeBridge.ts

this.messageBus.registerHandler('utils.example', async (data) => {
  const { cwd, name } = data;
  try {
    const context = await this.getContext(cwd);
    
    // Do something with context and params
    const result = await someOperation(name);
    
    return {
      success: true,
      data: {
        result,
      },
    };
  } catch (error: any) {
    return {
      success: false,
      error: error.message || 'Failed to execute example',
    };
  }
});

nodeBridge.types.ts

type UtilsExampleInput = {
  cwd: string;
  name: string;
};

type UtilsExampleOutput = {
  success: boolean;
  error?: string;
  data?: {
    result: string;
  };
};

// In HandlerMap:
'utils.example': {
  input: UtilsExampleInput;
  output: UtilsExampleOutput;
};

Notes

• Handlers are async functions that receive data parameter
• Use this.getContext(cwd) to get the Context instance (cached per cwd)
• Context provides access to: config, paths, mcpManager, productName, version, etc.
• For long-running operations, consider using abort controllers (see git.clone pattern)
• For operations that emit progress, use this.messageBus.emitEvent() (see git.commit.output pattern)