OpenCode Development

Source: https://github.com/sst/opencode (packages/web/src/content/docs/)

OpenCode is an open source AI coding agent available as a terminal interface (TUI), desktop app, or IDE extension. It's provider-agnostic and supports MCP servers for extensibility.

Installation

# Install script
curl -fsSL https://opencode.ai/install | bash

# npm
npm install -g opencode-ai

# Homebrew
brew install opencode

# Bun
bun install -g opencode-ai

Quick Start

# Start TUI in current directory
opencode

# Start in specific directory
opencode /path/to/project

# Non-interactive mode
opencode -p "explain this codebase"

# With specific model
opencode --model anthropic/claude-sonnet-4-5-20250929

TUI Features

File References

Reference files with @ for fuzzy search:

How is auth handled in @packages/api/auth.ts?

Bash Commands

Start with ! to run shell commands:

!ls -la
!git status

Slash Commands

Configuration

Create opencode.json in your project root or ~/.config/opencode/:

{
  "$schema": "https://opencode.ai/config.json",
  "model": "anthropic/claude-sonnet-4-5-20250929",
  "provider": {
    "anthropic": {
      "api_key": "${ANTHROPIC_API_KEY}"
    }
  }
}

Environment Variables

# Provider API keys
ANTHROPIC_API_KEY=sk-ant-...
OPENAI_API_KEY=sk-...
GOOGLE_API_KEY=...

# OpenCode settings
OPENCODE_MODEL=anthropic/claude-sonnet-4-5-20250929

Tools

OpenCode has built-in tools that the LLM can use:

Configure Tools

{
  "$schema": "https://opencode.ai/config.json",
  "tools": {
    "write": true,
    "bash": true,
    "webfetch": false
  }
}

Agents

Define custom agents with specific behaviors:

<!-- ~/.config/opencode/agent/reviewer.md -->
---
description: Code review agent
mode: subagent
tools:
  write: false
  edit: false
---

You are a code reviewer. Analyze code for:
- Security vulnerabilities
- Performance issues
- Best practices

Agent Modes

• subagent: Called by other agents for specific tasks
• autonomous: Runs independently with minimal user input

MCP Servers

Add external tools via Model Context Protocol:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "filesystem": {
      "type": "local",
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/dir"]
    },
    "remote-server": {
      "type": "remote",
      "url": "https://mcp.example.com",
      "enabled": true
    }
  }
}

LSP Integration

OpenCode includes out-of-the-box LSP support. Configure additional servers:

{
  "$schema": "https://opencode.ai/config.json",
  "lsp": {
    "typescript": {
      "command": "typescript-language-server",
      "args": ["--stdio"]
    }
  }
}

Rules

Add project-specific instructions:

<!-- .opencode/rules.md -->
# Project Rules

- Use TypeScript for all new files
- Follow the existing code style
- Add tests for new features

Keybinds

Default leader key: Ctrl+X

Modes

Best Practices

1. Use file references (@file) to give context without copying content
2. Configure tool permissions for sensitive projects
3. Use agents for specialized tasks (review, planning, testing)
4. Enable LSP for better code understanding
5. Use MCP servers sparingly - they add to context size

Documentation Index

Syncing Documentation

cd skills/opencode
bun run scripts/sync-docs.ts