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, and conversion.
2. Bundled Assets (skills/, agents/, commands/): Battle-tested engineering content that is automatically discovered and registered by the plugin.

How It Works

Systematic utilizes three primary OpenCode plugin hooks to integrate seamlessly:

%%{init: {'theme': 'base', 'themeVariables': { 'primaryColor': '#1a1a2e', 'primaryTextColor': '#fff', 'primaryBorderColor': '#4FD1C5', 'lineColor': '#4FD1C5', 'secondaryColor': '#16213e', 'tertiaryColor': '#0f0f23'}}}%%
flowchart TB
    A[Plugin Loaded] --> B[config hook]
    A --> C[tool hook]
    A --> D[system.transform hook]

    B --> E[Merge bundled agents/commands/skills into OpenCode config]
    C --> F[Register systematic_skill tool]
    D --> G[Inject bootstrap prompt into every conversation]

    style A fill:#1a1a2e,stroke:#4FD1C5,color:#fff
    style B fill:#16213e,stroke:#4FD1C5,color:#4FD1C5
    style C fill:#16213e,stroke:#E91E8C,color:#E91E8C
    style D fill:#16213e,stroke:#F5A623,color:#F5A623
    style E fill:#0f0f23,stroke:#4FD1C5,color:#B2F5EA
    style F fill:#0f0f23,stroke:#E91E8C,color:#B2F5EA
    style G fill:#0f0f23,stroke:#F5A623,color:#B2F5EA

1. config Hook

The config hook is responsible for discovery and merging. It recursively walks the bundled asset directories (skills/, agents/, commands/) 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	Handles CEP to OpenCode format conversion	src/lib/converter.ts
findSkillsInDir	Discovers bundled skills	src/lib/skills.ts

Technical Stack

Systematic is built with modern web technologies:

• Runtime: Bun (Node.js API compatible)
• Language: TypeScript 5.7+ in strict mode
• Modules: ESM ("type": "module")
• Linter: Biome
• Testing: bun:test