This skill should be used when creating extensions for Claude Code or OpenCode, including plugins, commands, agents, skills, and custom tools. Covers both platforms with format specifications, best practices, and the ai-eng-system build system.
npx claudepluginhub v1truv1us/ai-eng-system --plugin ai-eng-learningThis skill uses the workspace's default tool permissions.
**Creating high-quality plugins is critical to your development workflow's long-term success.** Plugins are used repeatedly by yourself and others. Design flaws, poor documentation, or broken functionality compound over time and across users. A well-designed plugin becomes a trusted tool used daily; a poorly designed plugin becomes abandoned technical debt. Invest time in architecture, testing,...
Creates isolated Git worktrees for feature branches with prioritized directory selection, gitignore safety checks, auto project setup for Node/Python/Rust/Go, and baseline verification.
Executes implementation plans in current session by dispatching fresh subagents per independent task, with two-stage reviews: spec compliance then code quality.
Dispatches parallel agents to independently tackle 2+ tasks like separate test failures or subsystems without shared state or dependencies.
Creating high-quality plugins is critical to your development workflow's long-term success. Plugins are used repeatedly by yourself and others. Design flaws, poor documentation, or broken functionality compound over time and across users. A well-designed plugin becomes a trusted tool used daily; a poorly designed plugin becomes abandoned technical debt. Invest time in architecture, testing, and documentation—the returns multiply across all future uses.
** approach plugin development systematically.** Plugins require careful planning: understand the problem, design the API, implement incrementally, test thoroughly, and document comprehensively. Don't rush to code—clarify requirements, define interfaces, and consider edge cases first. Build iteratively, validate frequently, and refactor continuously. Every design decision impacts maintainability and extensibility.
The create a plugin that balances specificity with flexibility perfectly, but if you can:
The challenge is designing plugins that solve specific problems while staying flexible enough for future use cases. Can you create focused, opinionated tools that don't paint yourself into corners?
After completing or reviewing plugin development, rate your confidence from 0.0 to 1.0:
Identify uncertainty areas: Is the plugin's purpose clear? Are there edge cases unhandled? Will the plugin work as requirements change? What's the maintenance burden?
The ai-eng-system supports extension development for both Claude Code and OpenCode through a unified content system with automated transformation. Understanding this system enables creating well-organized, maintainable extensions that integrate seamlessly with both platforms.
| Type | Claude Code | OpenCode | Shared Format |
|---|---|---|---|
| Commands | ✅ YAML frontmatter | ✅ Table format | YAML frontmatter |
| Agents | ✅ YAML frontmatter | ✅ Table format | YAML frontmatter |
| Skills | ✅ Same format | ✅ Same format | SKILL.md |
| Hooks | ✅ hooks.json | ✅ Plugin events | Platform-specific |
| Custom Tools | ❌ (use MCP) | ✅ tool() helper | OpenCode only |
| MCP Servers | ✅ .mcp.json | ✅ Same format | Same format |
Create content in content/ directory, let build.ts transform to platform formats:
content/
├── commands/my-command.md → dist/.claude-plugin/commands/
│ → dist/.opencode/command/ai-eng/
└── agents/my-agent.md → dist/.claude-plugin/agents/
→ dist/.opencode/agent/ai-eng/
Create directly in platform directories:
.claude/commands/, .claude-plugin/.opencode/command/, .opencode/agent/| Location | Claude Code | OpenCode |
|---|---|---|
| Project | .claude/ | .opencode/ |
| Global | ~/.claude/ | ~/.config/opencode/ |
Canonical (content/):
---
name: my-command
description: What this command does
agent: build # Optional: which agent handles this
subtask: true # Optional: run as subtask
temperature: 0.3 # Optional: temperature
tools: # Optional: tool restrictions
read: true
write: true
---
Claude Code Output: Same format (YAML frontmatter)
OpenCode Output: YAML frontmatter with OpenCode-compatible fields
---
description: Description here
agent: build
---
Canonical (content/):
---
name: my-agent
description: Use this agent when... <example>...</example>
mode: subagent
color: cyan
temperature: 0.3
tools:
read: true
write: true
---
Claude Code Output: Same format (YAML frontmatter)
OpenCode Output: YAML frontmatter with OpenCode-compatible fields
---
description: Description here
mode: subagent
---
Both platforms use identical format:
skill-name/
├── SKILL.md (required)
│ ├── YAML frontmatter (name, description)
│ └── Markdown body (1,000-3,000 words)
└── Bundled Resources (optional)
├── references/ # Detailed documentation
├── examples/ # Working code
└── scripts/ # Utility scripts
Use TypeScript with tool() helper:
import { tool } from "@opencode-ai/plugin"
export default tool({
description: "Tool description",
args: {
param: tool.schema.string().describe("Parameter description"),
},
async execute(args, context) {
// Tool implementation
return result
},
})
ai-eng-system/
├── content/
│ ├── commands/ # Add new commands here
│ └── agents/ # Add new agents here
├── skills/
│ └── plugin-dev/ # This skill
└── build.ts # Transforms to both platforms
Project-local:
.claude/commands/, .claude-plugin/.opencode/command/, .opencode/agent/Global:
~/.claude/commands/, ~/.claude-plugin/~/.config/opencode/command/, ~/.config/opencode/agent/Components:
hooks/hooks.json.mcp.jsonManifest: .claude-plugin/plugin.json
{
"name": "plugin-name",
"version": "1.0.0",
"description": "Brief description",
"commands": ["./commands/*"],
"mcpServers": "./.mcp.json"
}
Components:
Plugin: .opencode/plugin/plugin.ts
import { Plugin } from "@opencode-ai/plugin"
export default (async ({ client, project, directory, worktree, $ }) => {
return {
// Plugin hooks here
}
}) satisfies Plugin
Use plugin-dev commands:
/ai-eng/create-agent - Create new agent/ai-eng/create-command - Create new command/ai-eng/create-skill - Create new skill/ai-eng/create-tool - Create new custom toolcd ai-eng-system
bun run build # Build all platforms
bun run build --watch # Watch mode
bun run build --validate # Validate content
Claude Code:
claude plugin add https://github.com/v1truv1us/ai-eng-system
OpenCode:
# Project-local
./setup.sh
# Global
./setup-global.sh
content/references/claude-code-plugins.md - Claude Code specificsreferences/opencode-plugins.md - OpenCode specificsreferences/command-format.md - Command syntax guidereferences/agent-format.md - Agent configuration guidereferences/skill-format.md - Skills specificationreferences/opencode-tools.md - Custom tool developmentStudy existing components in ai-eng-system:
content/commands/plan.md - Command structurecontent/agents/architect-advisor.md - Agent structureskills/prompting/incentive-prompting/SKILL.md - Skill structurebun run build --validate to check contentThe plugin-dev system integrates seamlessly with existing ai-eng-system components:
/ai-eng/plan - Implementation planning/ai-eng/review - Code review/ai-eng/work - Task executionai-eng/architect-advisor - Architecture guidanceai-eng/frontend-reviewer - Frontend reviewai-eng/seo-specialist - SEO optimization/ai-eng/create-plugin - Full plugin development workflow/ai-eng/create-agent - Quick agent creation/ai-eng/create-command - Quick command creation/ai-eng/create-skill - Quick skill creation/ai-eng/create-tool - Quick tool creationAll use the same quality standards and research-backed prompting techniques.