OpenCodeMCP by silvabyte - MCP Server

Conversational Coding MCP Server

An MCP (Model Context Protocol) server that enables conversational coding via ChatGPT or any MCP-enabled LLM. Talk to your codebase from anywhere - on a bike ride, fishing, or walking the dog.

What It Does

This server bridges ChatGPT to OpenCode, allowing you to:

Explore projects - "Show me the folder structure of the horizon backend"
Read code - "What does the status-change handler do?"
Modify code - "Refactor this function to use async/await"
Search - "Find all files that import the auth module"
Run commands - "Run the tests and tell me what fails"

All through natural conversation.

Architecture

You (speaking) → ChatGPT → MCP Server → OpenCode → Your Codebase

ChatGPT: Interprets your intent and calls MCP tools
MCP Server: Routes requests to OpenCode (this project)
OpenCode: AI coding agent that actually reads/writes files

Quick Start

Prerequisites

Bun runtime
OpenCode installed (npm i -g opencode-ai)

Installation

# Clone and install
git clone <repo>
cd opencodemcp
bun install

# Configure
cp .env.example .env
# Edit .env and set your MCP_API_KEY

Running

# Development (with hot reload)
bun run dev

# Production
bun run start

The server starts at http://localhost:9000/mcp

Exposing to ChatGPT

Use Cloudflare Tunnel to expose your local server:

# Install cloudflared
brew install cloudflared

# Create a tunnel (one-time)
cloudflared tunnel create mcp

# Run the tunnel
cloudflared tunnel run --url http://localhost:9000 mcp

Then configure ChatGPT to use your tunnel URL as an MCP endpoint.

Configuration

Environment variables (see .env.example):

Variable	Required	Description
`MCP_API_KEY`	Yes	API key for authenticating requests
`MCP_PORT`	No	Port to run on (default: 9000)
`OPENCODE_URL`	No	URL of existing OpenCode server
`PROJECT_ALIASES`	No	JSON array of project aliases

Project Aliases

Define friendly names for your projects:

PROJECT_ALIASES='[{"name":"horizon backend","path":"/Users/mat/dev/Horizon"},{"name":"my app","path":"/Users/mat/dev/MyApp"}]'

Then say "open the horizon backend" instead of the full path.

MCP Tools

The server exposes these tools to ChatGPT:

Tool	Description
`conversation`	Main interface - send any coding instruction
`list_files`	List files and directories
`read_file`	Read file contents
`find_text`	Search for text patterns
`find_files`	Find files by name
`get_project`	Get current project info
`list_projects`	List all projects
`list_sessions`	List active sessions
`get_messages`	Get session message history
`abort_session`	Stop current operation
`add_alias`	Add a project alias

Example Conversations

Opening a project:

"Open the horizon backend and show me the folder structure"

Exploring code:

"What files implement the analytics storage? Show me the main ones."

Making changes:

"Refactor the status-change handler - extract the shared logic into a utility"

Debugging:

"Run the tests and fix any failures"

Development

# Type check
bun run typecheck

# Run with hot reload
bun run dev

Project Structure

src/
├── index.ts           # Server bootstrap
├── routes.ts          # MCP tool definitions
├── auth.ts            # API key authentication
├── opencodeClient.ts  # OpenCode SDK wrapper
├── sessionManager.ts  # Session tracking
└── types.ts           # TypeScript interfaces

License

MIT