# Category & Skill System Guide This document provides a comprehensive guide to the **Category** and **Skill** systems, which form the extensibility core of Oh-My-OpenCode. ## 1. Overview Instead of delegating everything to a single AI agent, it's far more efficient to invoke **specialists** tailored to the nature of the task. - **Category**: "What kind of work is this?" (determines model, temperature, prompt mindset) - **Skill**: "What tools and knowledge are needed?" (injects specialized knowledge, MCP tools, workflows) By combining these two concepts, you can generate optimal agents through `sisyphus_task`. --- ## 2. Category System A Category is an agent configuration preset optimized for specific domains. ### Available Built-in Categories | Category | Optimal Model | Characteristics | Use Cases | |----------|---------------|-----------------|-----------| | `visual-engineering` | `gemini-3-pro` | High creativity (Temp 0.7) | Frontend, UI/UX, animations, styling | | `ultrabrain` | `gpt-5.2` | Maximum logical reasoning (Temp 0.1) | Architecture design, complex business logic, debugging | | `artistry` | `gemini-3-pro` | Artistic (Temp 0.9) | Creative ideation, design concepts, storytelling | | `quick` | `claude-haiku` | Fast (Temp 0.3) | Simple tasks, refactoring, script writing | | `writing` | `gemini-3-flash` | Natural flow (Temp 0.5) | Documentation, technical blogs, README writing | | `most-capable` | `claude-opus` | High performance (Temp 0.1) | Extremely difficult complex tasks | ### Usage Specify the `category` parameter when invoking the `sisyphus_task` tool. ```typescript sisyphus_task( category="visual-engineering", prompt="Add a responsive chart component to the dashboard page" ) ``` ### Sisyphus-Junior (Delegated Executor) When you use a Category, a special agent called **Sisyphus-Junior** performs the work. - **Characteristic**: Cannot **re-delegate** tasks to other agents. - **Purpose**: Prevents infinite delegation loops and ensures focus on the assigned task. --- ## 3. Skill System A Skill is a mechanism that injects **specialized knowledge (Context)** and **tools (MCP)** for specific domains into agents. ### Built-in Skills 1. **`git-master`** - **Capabilities**: Git expert. Detects commit styles, splits atomic commits, formulates rebase strategies. - **MCP**: None (uses Git commands) - **Usage**: Essential for commits, history searches, branch management. 2. **`playwright`** - **Capabilities**: Browser automation. Web page testing, screenshots, scraping. - **MCP**: `@playwright/mcp` (auto-executed) - **Usage**: For post-implementation UI verification, E2E test writing. 3. **`frontend-ui-ux`** - **Capabilities**: Injects designer mindset. Color, typography, motion guidelines. - **Usage**: For aesthetic UI work beyond simple implementation. ### Usage Add desired skill names to the `skills` array. ```typescript sisyphus_task( category="quick", skills=["git-master"], prompt="Commit current changes. Follow commit message style." ) ``` ### Skill Customization (SKILL.md) You can add custom skills directly to `.opencode/skills/` in your project root or `~/.claude/skills/` in your home directory. **Example: `.opencode/skills/my-skill/SKILL.md`** ```markdown --- name: my-skill description: My special custom skill mcp: my-mcp: command: npx args: ["-y", "my-mcp-server"] --- # My Skill Prompt This content will be injected into the agent's system prompt. ... ``` --- ## 4. Combination Strategies (Combos) You can create powerful specialized agents by combining Categories and Skills. ### 🎨 The Designer (UI Implementation) - **Category**: `visual-engineering` - **Skills**: `["frontend-ui-ux", "playwright"]` - **Effect**: Implements aesthetic UI and verifies rendering results directly in browser. ### 🏗️ The Architect (Design Review) - **Category**: `ultrabrain` - **Skills**: `[]` (pure reasoning) - **Effect**: Leverages GPT-5.2's logical reasoning for in-depth system architecture analysis. ### ⚡ The Maintainer (Quick Fixes) - **Category**: `quick` - **Skills**: `["git-master"]` - **Effect**: Uses cost-effective models to quickly fix code and generate clean commits. --- ## 5. sisyphus_task Prompt Guide When delegating, **clear and specific** prompts are essential. Include these 7 elements: 1. **TASK**: What needs to be done? (single objective) 2. **EXPECTED OUTCOME**: What is the deliverable? 3. **REQUIRED SKILLS**: Which skills should be used? 4. **REQUIRED TOOLS**: Which tools must be used? (whitelist) 5. **MUST DO**: What must be done (constraints) 6. **MUST NOT DO**: What must never be done 7. **CONTEXT**: File paths, existing patterns, reference materials **Bad Example**: > "Fix this" **Good Example**: > **TASK**: Fix mobile layout breaking issue in `LoginButton.tsx` > **CONTEXT**: `src/components/LoginButton.tsx`, using Tailwind CSS > **MUST DO**: Change flex-direction at `md:` breakpoint > **MUST NOT DO**: Modify existing desktop layout > **EXPECTED**: Buttons align vertically on mobile --- ## 6. Configuration Guide (oh-my-opencode.json) You can fine-tune categories in `oh-my-opencode.json`. ### Category Configuration Schema (CategoryConfig) | Field | Type | Description | |-------|------|-------------| | `model` | string | AI model ID to use (e.g., `anthropic/claude-opus-4-5`) | | `temperature` | number | Creativity level (0.0 ~ 2.0). Lower is more deterministic. | | `prompt_append` | string | Content to append to system prompt when this category is selected | | `thinking` | object | Thinking model configuration (`{ type: "enabled", budgetTokens: 16000 }`) | | `tools` | object | Tool usage control (disable with `{ "tool_name": false }`) | | `maxTokens` | number | Maximum response token count | ### Example Configuration ```jsonc { "categories": { // 1. Define new custom category "korean-writer": { "model": "google/gemini-3-flash-preview", "temperature": 0.5, "prompt_append": "You are a Korean technical writer. Maintain a friendly and clear tone." }, // 2. Override existing category (change model) "visual-engineering": { "model": "openai/gpt-5.2", // Can change model "temperature": 0.8 }, // 3. Configure thinking model and restrict tools "deep-reasoning": { "model": "anthropic/claude-opus-4-5", "thinking": { "type": "enabled", "budgetTokens": 32000 }, "tools": { "websearch_web_search_exa": false // Disable web search } } }, // Disable skills "disabled_skills": ["playwright"] } ```