OpenCode

Overview

OpenCode is an open-source AI coding agent that integrates with OpenClaw via ACP (Agent Client Protocol). It provides specialized coding capabilities including game development, multi-file projects, complex refactoring, and production-ready code generation.

Status: ✅ Fully tested - Built 12 production-ready games including Pac-Man, Space Invaders, Tetris, Q*bert, and more.

When to Use This Skill

Use OpenCode when:

1. Building games (HTML5 Canvas games work excellently)
2. Creating multi-file projects from scratch
3. Performing complex code refactoring across multiple files
4. Building production-ready applications with proper structure
5. Tasks requiring dedicated coding agent focus
6. The user explicitly asks to use OpenCode

Quick Start

Spawn OpenCode as ACP Subagent

// One-shot task (recommended for most builds)
sessions_spawn({
  runtime: "acp",
  agentId: "opencode",
  task: "Create a complete [game/app] in HTML/CSS/JavaScript...",
  mode: "run",
  cwd: "/path/to/project"
})

// Parallel builds (run multiple simultaneously)
sessions_spawn({...}) // Game 1
sessions_spawn({...}) // Game 2  
sessions_spawn({...}) // Game 3

Parallel Builds

OpenCode supports parallel execution - spawn multiple subagents simultaneously:

// Launch 3 games at once
const game1 = sessions_spawn({... Asteroids ...})
const game2 = sessions_spawn({... Doodle Jump ...})
const game3 = sessions_spawn({... Flappy Bird ...})

// All build concurrently, limited by slowest

Performance: 3 parallel games completed in ~1m 20s (same as single game)

Performance Expectations

Based on 12-game test suite:

Proven Game Templates

The following game types have been fully tested and verified:

Commands Reference

Core Commands

Utility Commands

Built-in Agents

• build - Full-access agent for development work (default)
• plan - Read-only agent for analysis and exploration
• @general - Subagent for complex searches

Configuration

ACP Integration

OpenCode is configured in OpenClaw. The ACP command is:

opencode acp

This starts JSON-RPC over stdio for ACP-compatible communication.

Providers

OpenCode supports multiple AI providers:

• OpenCode Zen (recommended)
• Claude (Anthropic)
• OpenAI
• Google Gemini
• Local models

Set API keys via opencode providers or environment variables.

Usage Patterns

Pattern 1: One-shot Build

sessions_spawn({
  runtime: "acp",
  agentId: "opencode",
  task: "Create a complete Snake game in HTML/CSS/JavaScript...",
  mode: "run",
  cwd: "/Users/jadegaul/.openclaw/workspace/codeprojects"
})

Pattern 2: Parallel Builds

// Build 3 games simultaneously
const builds = [
  sessions_spawn({ task: "Asteroids...", ... }),
  sessions_spawn({ task: "Doodle Jump...", ... }),
  sessions_spawn({ task: "Flappy Bird...", ... })
]

Pattern 3: Bug Fixes

// Fix existing code
sessions_spawn({
  runtime: "acp",
  agentId: "opencode",
  task: "Fix the bug in /path/to/file.html where...",
  mode: "run"
})

Pattern 4: Check Status

subagents({ action: "list" })

Pattern 5: Steer Running Subagent

subagents({
  action: "steer",
  target: "<runId>",
  message: "Continue with the implementation"
})

File Operations

OpenCode has full file system access:

• Read/write files
• Execute shell commands
• Navigate directories
• Git operations

Capabilities

• 100% open source (unlike Claude Code)
• Provider-agnostic - use any model
• LSP support - code intelligence
• Client/server architecture - run remotely
• Undo/redo - /undo and /redo commands
• Session sharing - /share creates shareable links

Best Practices

1. Be specific in task descriptions - include file paths, required features
2. Use mode: "run" for one-shot builds (faster)
3. Use mode: "session" for multi-step work
4. Test immediately - some games need spawn fixes
5. Parallel builds work great for 3+ independent tasks

Common Issues & Solutions

Issue: Game spawns in wrong position

Fix: Spawn OpenCode to add starting platform/position

Issue: Character dies immediately

Fix: Add spawn delay or ensure safe starting position

Issue: Controls not working

Fix: Check that touch + keyboard controls both specified

References

See references/opencode-docs.md for complete ACP documentation.

Test Results Summary

Total Games Built: 12
Total Build Time: ~15 minutes
Total Lines of Code: ~8,000+
Success Rate: 100% (with minor spawn fixes)

Average Build Times:

• Simple games: ~50s
• Medium games: ~1m 15s
• Complex games: ~1m 40s

OpenCode via ACP is production-ready for game development and coding tasks.