opencode
OpenCode Skill
OpenCode is an open source AI coding agent available as a terminal interface (TUI), desktop app, or IDE extension. It enables developers to work on code projects through conversational interactions with intelligent assistance for code explanation, implementation planning, code modification, and more.
Key Value Proposition: A flexible, multi-provider AI assistant with customizable agents, granular permissions, and extensive tool integrations that can be tailored for specific workflows like code review, documentation, security auditing, or development.
When to Use This Skill
- Setting up OpenCode for a new development environment
- Creating custom agents for specialized coding workflows
- Configuring permissions for team-based development
- Building automated scripts with OpenCode CLI
- Integrating MCP servers for extended capabilities
- Troubleshooting OpenCode configuration or tool issues
- Comparing OpenCode features with other AI coding assistants
When NOT to Use This Skill
- For Claude Code/Claude CLI specific features (different product)
- For GitHub Copilot configuration (use copilot-specific docs)
- For Cursor IDE settings (different AI editor)
- For generic LLM API usage (use provider-specific skills)
Core Concepts
Architecture Overview
┌─────────────────────────────────────────────────────────────────┐
│ OpenCode │
│ Terminal UI / Desktop App / IDE Extension │
└─────────────────────────────────────────────────────────────────┘
│
┌─────────────────────┼─────────────────────┐
│ │ │
▼ ▼ ▼
┌───────────────┐ ┌───────────────┐ ┌───────────────┐
│ Agents │ │ Tools │ │ Permissions │
├───────────────┤ ├───────────────┤ ├───────────────┤
│ • Build │ │ • read/write │ │ • allow │
│ • Plan │ │ • edit/patch │ │ • ask │
│ • Custom... │ │ • bash │ │ • deny │
│ • Subagents │ │ • grep/glob │ │ • Wildcards │
└───────────────┘ │ • webfetch │ └───────────────┘
│ • lsp │
│ • MCP servers │
└───────────────┘
│
┌─────────────────────┼─────────────────────┐
▼ ▼ ▼
┌───────────────┐ ┌───────────────┐ ┌───────────────┐
│ LLM Providers │ │ Sessions │ │ Commands │
├───────────────┤ ├───────────────┤ ├───────────────┤
│ • OpenAI │ │ • SQLite │ │ • /init │
│ • Claude │ │ • Persistence │ │ • /undo │
│ • Gemini │ │ • Export/ │ │ • /share │
│ • Groq │ │ Import │ │ • Custom... │
│ • Bedrock │ └───────────────┘ └───────────────┘
└───────────────┘
Agent Types
| Type | Description | Use Case |
|---|---|---|
| Primary Agent | Main assistant for direct interaction | Day-to-day development |
| Subagent | Specialized assistant for specific tasks | Research, exploration |
| Build (built-in) | Full tool access for development | Writing and modifying code |
| Plan (built-in) | Read-only for analysis | Planning without changes |
| General (subagent) | Multi-step task execution | Research and investigation |
| Explore (subagent) | Codebase navigation | Quick file/code searching |
Installation
Quick Install (Recommended)
# Install script
curl -fsSL https://raw.githubusercontent.com/opencode-ai/opencode/refs/heads/main/install | bash
# Homebrew (macOS/Linux)
brew install opencode-ai/tap/opencode
# npm
npm install -g opencode
# Go
go install github.com/opencode-ai/opencode@latest
Verify Installation
opencode --version
Configuration
Configuration Files
OpenCode uses opencode.json in your project root or global config at ~/.config/opencode/:
{
"provider": "anthropic",
"model": "claude-sonnet-4-20250514",
"permission": {
"edit": "ask",
"bash": "ask"
},
"agent": {
"build": {
"model": "claude-sonnet-4-20250514"
},
"plan": {
"model": "claude-sonnet-4-20250514",
"tools": {
"write": false,
"bash": false
}
}
}
}
Environment Variables
# API Keys (choose your provider)
export ANTHROPIC_API_KEY="sk-ant-..."
export OPENAI_API_KEY="sk-..."
export GOOGLE_API_KEY="..."
export GROQ_API_KEY="..."
# OpenCode Settings
export OPENCODE_CONFIG="~/.config/opencode/opencode.json"
export OPENCODE_PERMISSION="ask" # Default permission level
export OPENCODE_AUTO_SHARE="true" # Auto-share sessions
export OPENCODE_EXPERIMENTAL_LSP_TOOL="true" # Enable LSP
Tools Reference
Built-in Tools
| Tool | Description | Permission |
|---|---|---|
read |
Read file contents from codebase | allow |
write |
Create or overwrite files | edit |
edit |
Modify files using exact string replacements | edit |
patch |
Apply patch files to code | edit |
grep |
Search file contents using regex | allow |
glob |
Find files by pattern (e.g., **/*.js) |
allow |
list |
List files and directories | allow |
bash |
Execute shell commands | ask |
webfetch |
Fetch and read web pages | ask |
lsp |
Language Server Protocol (experimental) | allow |
skill |
Load SKILL.md file content | allow |
question |
Ask user questions during execution | allow |
todoread/todowrite |
Task tracking during sessions | allow |
Tool Configuration
{
"permission": {
"*": "ask",
"read": "allow",
"grep": "allow",
"glob": "allow",
"list": "allow",
"bash": {
"*": "ask",
"git *": "allow",
"npm *": "allow",
"rm *": "deny"
}
}
}
Creating Custom Agents
Interactive Creation
opencode agent create
This guides you through:
- Selecting storage location (global or project)
- Defining agent purpose
- Auto-generating system prompts
- Choosing accessible tools
- Creating markdown configuration
Agent Configuration (JSON)
{
"agent": {
"reviewer": {
"description": "Code review specialist",
"mode": "subagent",
"model": "claude-sonnet-4-20250514",
"temperature": 0.3,
"prompt": ".opencode/agent/reviewer.md",
"tools": {
"read": true,
"grep": true,
"glob": true,
"edit": false,
"bash": false
},
"permission": {
"webfetch": "deny"
},
"maxSteps": 20
}
}
}
Agent Configuration (Markdown)
Create .opencode/agent/reviewer.md:
---
description: Code review specialist for quality and security
mode: subagent
model: claude-sonnet-4-20250514
temperature: 0.3
tools:
read: true
grep: true
glob: true
edit: false
bash: false
---
You are a code review specialist focused on:
1. Code quality and best practices
2. Security vulnerabilities
3. Performance issues
4. Maintainability concerns
When reviewing code:
- Identify issues by severity (critical, major, minor)
- Provide specific line references
- Suggest concrete improvements
- Consider the project's existing patterns
Agent Parameters
| Parameter | Type | Description |
|---|---|---|
description |
string | Brief explanation (required) |
mode |
string | primary, subagent, or all |
model |
string | Override default model |
temperature |
float | Response randomness (0.0-1.0) |
prompt |
string | Path to system prompt file |
tools |
object | Enable/disable specific tools |
permission |
object | Override permissions |
maxSteps |
number | Limit iterations before text-only |
Custom Commands
Command Structure
Create .opencode/command/review.md:
---
description: Review code changes
agent: reviewer
---
Review the following code changes:
$ARGUMENTS
Focus on:
1. Security vulnerabilities
2. Performance issues
3. Code style violations
4. Missing tests
Using Arguments
---
description: Create a component
---
Create a new React component named $1 in the $2 directory.
Requirements:
- TypeScript
- Styled with Tailwind
- Include tests
Usage: /component Button components/ui
Including Shell Output
---
description: Review recent changes
---
Review the following git diff:
`!git diff HEAD~1`
Summarize changes and identify any issues.
File References
---
description: Explain architecture
---
Based on the architecture documentation:
@ARCHITECTURE.md
Explain how the authentication system works.
CLI Reference
TUI Mode (Default)
# Start in current directory
opencode
# Start in specific project
opencode /path/to/project
# Continue last session
opencode --continue
# Use specific session
opencode --session <session-id>
# Override model
opencode --model claude-sonnet-4-20250514
Non-Interactive Mode
# Run single prompt
opencode run "explain this codebase"
# Run with file context
opencode run --file src/main.ts "add error handling"
# Run custom command
opencode run --command review
# Output format
opencode run --format json "list all functions"
Server Mode
# Start headless server
opencode serve --port 8080
# Start with web interface
opencode web --port 8080
# Connect to remote server
opencode attach http://localhost:8080
Agent Management
# Create new agent
opencode agent create
# List all agents
opencode agent list
MCP Integration
# Add MCP server
opencode mcp add <server-name>
# List MCP servers
opencode mcp list
# Debug MCP connection
opencode mcp debug <server-name>
Session Management
# List sessions
opencode session list --max-count 10
# Export session
opencode export <session-id>
# Import session
opencode import session.json
# View usage stats
opencode stats --days 7
Project Initialization
Generate AGENTS.md
opencode
/init
This analyzes your project and generates AGENTS.md containing:
- Project structure overview
- Key patterns and conventions
- Technology stack
- Important files and directories
Best Practice: Commit AGENTS.md to version control so OpenCode understands your codebase.
Permissions System
Permission Levels
| Level | Behavior |
|---|---|
allow |
Executes without approval |
ask |
Prompts for user approval |
deny |
Blocks execution |
Approval Responses
When prompted:
once- Approve single requestalways- Approve matching requests for sessionreject- Deny the request
Default Permissions
Most tools default to allow, except:
doom_loop-ask(safety feature)external_directory-ask(safety feature).env*files -deny(security)
Agent-Level Overrides
Agent permissions take precedence over global:
{
"permission": {
"bash": "ask"
},
"agent": {
"build": {
"permission": {
"bash": "allow"
}
}
}
}
Common Use Cases
Code Review Agent
---
description: Systematic code review
mode: subagent
tools:
read: true
grep: true
edit: false
bash: false
---
You are a code reviewer. For each review:
1. Check for security vulnerabilities
2. Identify performance bottlenecks
3. Ensure code follows project patterns
4. Verify test coverage
5. Suggest improvements
Format findings as:
- CRITICAL: [issue]
- MAJOR: [issue]
- MINOR: [issue]
Documentation Agent
---
description: Documentation writer
mode: subagent
tools:
read: true
glob: true
write: true
bash: false
---
You write clear, comprehensive documentation.
When documenting:
1. Follow project's existing doc style
2. Include code examples
3. Document edge cases
4. Keep language accessible
Security Audit Agent
---
description: Security vulnerability scanner
mode: subagent
tools:
read: true
grep: true
bash: false
webfetch: true
---
You are a security auditor. Scan for:
1. Injection vulnerabilities (SQL, XSS, command)
2. Authentication/authorization issues
3. Sensitive data exposure
4. Insecure dependencies
5. Misconfigurations
Reference OWASP Top 10 for classification.
Troubleshooting
Agent Not Invoking
Issue: Custom agent doesn't respond to @mention
Solutions:
- Verify agent file is in correct location (
.opencode/agent/or~/.config/opencode/agent/) - Check
modeis set correctly (subagentfor @mentions) - Ensure YAML frontmatter is valid
- Try
opencode agent listto verify registration
Permission Denied
Issue: Tool execution blocked unexpectedly
Solutions:
- Check global permissions in
opencode.json - Verify agent-specific overrides
- Use
opencode run --permission allowfor testing - Check for conflicting wildcard patterns
Tool Not Working
Issue: grep/glob returns no results
Solutions:
- Check if files are in
.gitignore(excluded by default) - Create
.ignorefile to include ignored directories - Verify pattern syntax is correct
LLM Connection Issues
Issue: Provider not responding
Solutions:
- Verify API key is set correctly
- Check network connectivity
- Run
opencode modelsto list available models - Try
opencode models --refreshto refresh cache
Resources
Official Documentation
Source Code
Related Projects
- Charm - Terminal UI framework
- MCP Protocol - Model Context Protocol
Version History
- 1.0.0 (2026-01-12): Initial skill release
- Complete OpenCode agent system documentation
- Built-in and custom agent configuration
- Tools reference with permission system
- CLI commands and usage patterns
- Custom commands and SKILL.md integration
- MCP server integration
- Common agent templates (review, docs, security)
- Troubleshooting guide