pulsar-mcp

MCP (Model Context Protocol) server for Pulsar editor - provides editor tools to Claude and other AI assistants.

Features

• MCP protocol version 2025-11-25 with tool annotations support
• HTTP bridge server running inside Pulsar for direct editor API access
• Standalone MCP server script for Claude CLI integration
• Built-in editor tools (get/set editor content, open/save files, manage selections)
• Extensible: other packages can register additional tools via the mcp-tools service

Installation

To install pulsar-mcp search for pulsar-mcp in the Install pane of the Pulsar settings or run ppm install pulsar-mcp. Alternatively, you can run ppm install asiloisad/pulsar-pulsar-mcp to install a package directly from the GitHub repository.

Commands

Command	Description
Pulsar MCP: Start	Start the MCP bridge server
Pulsar MCP: Stop	Stop the MCP bridge server
Pulsar MCP: Status	Show current bridge status and port

Configuration

Setting	Description	Default
Auto Start	Automatically start bridge when Pulsar opens	true
Bridge Base Port	Base port for MCP bridge (auto-increments for multiple windows)	3000
Debug Mode	Enable debug logging to console	false

Built-in Tools

Tool	Description
GetActiveEditor	Get editor metadata (path, grammar, modified, lineCount)
ReadText	Read buffer content with line pagination support
WriteText	Write text at cursor or replace range
OpenFile	Open a file in editor with optional position
SaveFile	Save a file (active editor or specific path)
GetSelections	Get all selections/cursors with positions and text
SetSelections	Set multiple selections/cursors at specific positions
CloseFile	Close an editor tab
GetProjectPaths	Get project root folders
AddProjectPath	Add a folder to project roots

Note: Editor tools (ReadText, WriteText, GetSelections, SetSelections) operate on the active editor only. For reading/writing other files, use the agent's built-in file tools.

Tool Details

GetActiveEditor - Returns metadata only (use ReadText for content, GetSelections for cursors):

{ "path": "/file.js", "grammar": "JavaScript", "modified": false, "lineCount": 100 }

ReadText - Read buffer content with pagination for large files:

ReadText()                                    // Full content (small files only)
ReadText({limit: 100})                        // First 100 lines
ReadText({offset: 100, limit: 100})           // Lines 100-199
ReadText({start: {row: 0, column: 0}, end: {row: 50, column: 0}})  // Position range
// Returns: { content, path, totalLines, hasMore, range }

WriteText - Insert or replace text:

WriteText({text: "hello"})                    // At cursor/selection
WriteText({text: "new", start: {row: 5, column: 0}})  // Insert at position
WriteText({text: "new", start: {...}, end: {...}})    // Replace range

MCP Client Integration

The standalone MCP server (lib/server.js) can be used with any MCP-compatible client.

{
  "mcpServers": {
    "pulsar": {
      "command": "node",
      "args": ["~/.pulsar/packages/pulsar-mcp/lib/server.js"]
    }
  }
}

On Windows, use %USERPROFILE%\.pulsar\packages\pulsar-mcp\lib\server.js.

Extending with Custom Tools

Other Pulsar packages can provide additional MCP tools by implementing the mcp-tools service:

// In your package.json
{
  "providedServices": {
    "mcp-tools": {
      "versions": {
        "1.0.0": "provideMcpTools"
      }
    }
  }
}

// In your main.js
provideMcpTools() {
  return [
    {
      name: "MyCustomTool",
      description: "Description for the AI",
      inputSchema: {
        type: "object",
        properties: {
          param: { type: "string", description: "Parameter description" }
        },
        required: ["param"]
      },
      annotations: { readOnlyHint: true },
      execute({ param }) {
        // Tool implementation
        return { result: "data" };
      }
    }
  ];
}

Tool Annotations

MCP 2025-11-25 supports tool annotations to hint behavior:

Annotation	Description
readOnlyHint	true if tool only reads data, false if it modifies state
destructiveHint	true if tool performs destructive actions (e.g., closing files)

Service API

The pulsar-mcp service provides:

// Get the service
consumePulsarMcp(service) {
  // Get current bridge port
  const port = service.getBridgePort();

  // Check if bridge is running
  const running = service.isRunning();

  // Get path to MCP server script
  const serverPath = service.getServerPath();
}

Contributing

Got ideas to make this package better, found a bug, or want to help add new features? Just drop your thoughts on GitHub — any feedback's welcome!