MCP Extension for SillyTavern

This extension adds WebSocket-based tool execution support to SillyTavern, allowing external tools to be registered and executed through a standardized interface.

Features

WebSocket server for real-time communication
Tool registration and execution system
JSON Schema validation for tool definitions
Real-time execution status updates
Configurable logging and WebSocket settings
Web-based settings UI integrated into SillyTavern

Related MCP server: Modular MCP Server & Client

Installation

Method 1: Web Interface (Recommended)

See INSTRUCTIONS.md for step-by-step instructions on installing through SillyTavern's web interface.

Method 2: Manual Installation

Clone this repository into your SillyTavern plugins directory:
cd /path/to/SillyTavern/plugins git clone https://github.com/CG-Labs/SillyTavern-MCP-Extension.git mcp-extension
Install dependencies:
cd mcp-extension npm install
Restart SillyTavern

Configuration

The extension can be configured through the SillyTavern UI under Settings > Extensions > MCP Extension.

Available Settings

WebSocket Port: The port number for the WebSocket server (default: 5005)
Log Level: Logging verbosity level (debug, info, warn, error)

Usage

Registering a Tool

To register a tool, send a WebSocket message with the following format:

{ "type": "register_tool", "data": { "name": "example_tool", "schema": { "type": "object", "properties": { "param1": { "type": "string", "description": "First parameter" }, "param2": { "type": "number", "description": "Second parameter" } }, "required": ["param1"] } } }

Executing a Tool

To execute a registered tool, send a WebSocket message with the following format:

{ "type": "execute_tool", "data": { "executionId": "unique_execution_id", "name": "example_tool", "args": { "param1": "value1", "param2": 42 } } }

Execution Status Updates

The extension broadcasts execution status updates to all connected clients:

Execution Started

{ "type": "tool_execution_started", "data": { "executionId": "unique_execution_id", "name": "example_tool", "args": { "param1": "value1", "param2": 42 } } }

Execution Completed

{ "type": "tool_execution_completed", "data": { "executionId": "unique_execution_id", "result": { // Tool-specific result data } } }

Execution Failed

{ "type": "tool_execution_failed", "data": { "executionId": "unique_execution_id", "error": { "code": "ERROR_CODE", "message": "Error message" } } }

Error Codes

INVALID_NAME: Invalid tool name
INVALID_SCHEMA: Invalid tool schema
INVALID_URI: Invalid resource URI
INVALID_HANDLER: Invalid handler implementation
INVALID_ARGUMENTS: Invalid tool arguments
TOOL_EXISTS: Tool already registered
TOOL_NOT_FOUND: Tool not found
TOOL_EXECUTION_FAILED: Tool execution failed
SERVER_ERROR: Internal server error

Development

Project Structure

mcp-extension/ ├── index.js # Main plugin entry point ├── manifest.json # Plugin manifest ├── package.json # Dependencies and scripts ├── public/ # Public assets │ ├── script.js # Client-side JavaScript │ ├── style.css # Client-side styles │ └── templates/ # HTML templates ├── utils/ # Utility modules │ ├── errors.js # Error handling │ ├── logger.js # Logging utility │ └── validation.js # Input validation └── README.md # This documentation

Adding New Tools

To add a new tool:

Connect to the WebSocket server
Register your tool with a schema
Listen for execution requests
Handle execution and return results

Example tool implementation:

Contributing

Fork the repository
Create a feature branch
Commit your changes
Push to the branch
Create a Pull Request

Support

If you encounter any issues or have questions:

Check the GitHub Issues for existing problems
Create a new issue if your problem hasn't been reported
Join the SillyTavern Discord community for support

License

MIT License - see LICENSE file for details

SillyTavern MCP Server