Architecture

Systematic is designed as a lightweight yet powerful extension for OpenCode. It leverages native plugin hooks to inject structured workflows and specialized agents into your development environment.

Overview

The plugin is divided into two main parts:

1. TypeScript Source (src/): The core logic that handles plugin registration, asset discovery, config validation, and model availability resolution.
2. Bundled Assets (skills/ and agents/): Structured engineering workflows and specialized agent definitions that are automatically discovered and registered by the plugin.

How It Works

Systematic utilizes three primary OpenCode plugin hooks to integrate seamlessly:

1. config Hook

The config hook is responsible for discovery and merging. It recursively walks the bundled asset directories (skills/ and agents/) and merges their definitions into your active OpenCode configuration. This ensures that agents like @architecture-strategist are available without manual setup.

2. tool Hook

The plugin registers a custom tool called systematic_skill. This tool is used by the AI to load the full content of bundled skills on demand. While OpenCode has a native skill tool, systematic_skill provides optimized access to the plugin’s bundled content.

3. system.transform Hook

This hook allows Systematic to inject a “bootstrap” instruction into the AI’s system prompt at the start of every conversation. This instruction (from the using-systematic skill) teaches the AI how to:

• Discover available workflows.
• Use the systematic_skill tool.
• Follow the “invoke before response” discipline.

Code Map

For developers looking to contribute or understand the implementation, here are the key modules:

| Symbol | Role | Location | |--------|------|----------| | SystematicPlugin | Main plugin factory | src/index.ts | | createConfigHandler | Implements the config hook logic | src/lib/config-handler.ts | | createSkillTool | Implements the systematic_skill tool | src/lib/skill-tool.ts | | getBootstrapContent | Handles system prompt injection | src/lib/bootstrap.ts | | convertContent | Claude Code-to-OpenCode format conversion (CLI) | src/lib/converter.ts | | findSkillsInDir | Discovers bundled skills | src/lib/skills.ts |