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Guide: Adding a New Skill

Prerequisites: Load plugins/context/capabilities/events_skills.md first Purpose: Step-by-step workflow for adding a new skill Related: See plugins/context/architecture/overview.md for plugin concepts

Overview

Adding a new skill involves:

1. Creating the skill directory structure
2. Creating the SKILL.md file
3. Creating the router script (for CLI-based skills)
4. Creating skill content/scripts
5. Registering the skill (if needed)
6. Testing the skill

Time: ~10-15 minutes

Step 1: Create Skill Directory

Choose Skill Name

Skill names should be:

• kebab-case: task-management, brand-guidelines, api-reference
• Descriptive: Clear indication of what the skill provides
• Short: Avoid overly long names (max 3-4 words)

Create Directory Structure

# Create skill directory
mkdir -p .opencode/skill/{skill-name}

# Create subdirectories as needed
mkdir -p .opencode/skill/{skill-name}/scripts

Standard Skill Structure

.opencode/skill/{skill-name}/
├── SKILL.md              # Required: Main skill documentation
├── router.sh             # Optional: CLI router script
└── scripts/
    └── skill-cli.ts      # Optional: CLI tool implementation

Step 2: Create SKILL.md

The SKILL.md file is required and provides skill documentation and integration details.

Optional: Claude Code Skills

Claude Code Skills live in .claude/skills/{skill-name}/SKILL.md and support extra frontmatter:

• allowed-tools for tool restrictions
• context + agent to run in a forked subagent
• hooks for lifecycle events
• user-invocable to hide from slash menu

Keep descriptions keyword-rich so auto-discovery triggers reliably. See ../to-be-consumed/claude-code-docs/agent-skills.md for full details.

SKILL.md Frontmatter

---
name: {skill-name}
description: Brief description of what the skill provides
---

# Skill Name

**Purpose**: What this skill helps users do

## What I do

- Feature 1
- Feature 2
- Feature 3

## How to use me

### Basic Commands

```bash
# Example command 1
npx ts-node .opencode/skill/{skill-name}/scripts/skill-cli.ts command1

# Example command 2
npx ts-node .opencode/skill/{skill-name}/scripts/skill-cli.ts command2

Command Reference

Examples

Example 1

$ npx ts-node .opencode/skill/{skill-name}/scripts/skill-cli.ts example

Expected output or behavior

Architecture

.opencode/
└── skill/
    └── {skill-name}/
        ├── SKILL.md              # This file
        ├── router.sh             # CLI router
        └── scripts/
            └── skill-cli.ts      # CLI implementation

Integration

With Agents

This skill integrates with agents by:

• Description of how agents use the skill
• Example agent prompt that invokes the skill

With OpenCode Events

The skill uses OpenCode event hooks:

• tool.execute.before - For [what it does]
• tool.execute.after - For [what it does]

Step 3: Create Router Script (Optional)

For CLI-based skills, create a router.sh script:

#!/bin/bash
# Router script for {skill-name} skill

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Default to help if no arguments
if [ $# -eq 0 ]; then
    echo "Usage: bash router.sh <command> [options]"
    echo "Run 'bash router.sh help' for more information"
    exit 1
fi

COMMAND="$1"
shift

# Route to appropriate script
case "$COMMAND" in
    help|--help|-h)
        echo "{Skill Name} - Skill Description"
        echo ""
        echo "Usage: bash router.sh <command> [options]"
        echo ""
        echo "Commands:"
        echo "  command1    Description of command1"
        echo "  command2    Description of command2"
        echo "  help        Show this help message"
        ;;
    command1)
        npx ts-node "$SCRIPT_DIR/scripts/skill-cli.ts" command1 "$@"
        ;;
    command2)
        npx ts-node "$SCRIPT_DIR/scripts/skill-cli.ts" command2 "$@"
        ;;
    *)
        echo "Unknown command: $COMMAND"
        echo "Run 'bash router.sh help' for available commands"
        exit 1
        ;;
esac

Make Router Executable

chmod +x .opencode/skill/{skill-name}/router.sh

Step 4: Create CLI Implementation

Basic CLI Structure

#!/usr/bin/env ts-node
// CLI implementation for {skill-name} skill

interface Args {
  command: string
  [key: string]: any
}

async function main() {
  const args = parseArgs()

  switch (args.command) {
    case 'command1':
      await handleCommand1(args)
      break
    case 'command2':
      await handleCommand2(args)
      break
    case 'help':
    default:
      showHelp()
  }
}

function parseArgs(): Args {
  const args = process.argv.slice(2)
  return {
    command: args[0] || 'help',
    ...parseOptions(args.slice(1))
  }
}

async function handleCommand1(args: Args) {
  // Implementation
  console.log('Running command1...')
}

function showHelp() {
  console.log(`
{ Skill Name }

Usage: npx ts-node scripts/skill-cli.ts <command> [options]

Commands:
  command1    Description of command1
  command2    Description of command2
  help        Show this help message

Options:
  --option1   Description of option1
  --option2   Description of option2
`)
}

main().catch(console.error)

Step 5: Register in Registry (Optional)

If the skill should be included in profiles, add it to registry.json:

Add to Components

{
  "skills": [
    {
      "id": "{skill-name}",
      "name": "Skill Name",
      "type": "skill",
      "path": ".opencode/skill/{skill-name}/SKILL.md",
      "description": "Brief description",
      "tags": ["tag1", "tag2"],
      "dependencies": []
    }
  ]
}

Add to Profiles

{
  "profiles": {
    "essential": {
      "components": [
        "skill:{skill-name}"
      ]
    }
  }
}

Step 6: Test the Skill

Test CLI Commands

# Test help
bash .opencode/skill/{skill-name}/router.sh help

# Test command1
bash .opencode/skill/{skill-name}/router.sh command1 --option value

# Test with npx
npx ts-node .opencode/skill/{skill-name}/scripts/skill-cli.ts help

Test OpenCode Integration

If the skill uses OpenCode events:

1. Call the skill via OpenCode
2. Verify event hooks fire correctly
3. Check conversation history for skill content injection
4. Verify output enhancement works

Example: Creating Task-Management Skill

Directory Creation

mkdir -p .opencode/skill/task-management/scripts

SKILL.md

---
name: task-management
description: Task management CLI for tracking feature subtasks
---

# Task Management Skill

**Purpose**: Track and manage feature subtasks

## What I do

- Track task progress
- Show next eligible tasks
- Identify blocked tasks
- Mark completion
- Validate task integrity

## Usage

```bash
# Show all task statuses
npx ts-node .opencode/skill/task-management/scripts/task-cli.ts status

# Show next eligible tasks
npx ts-node .opencode/skill/task-management/scripts/task-cli.ts next

# Mark complete
npx ts-node .opencode/skill/task-management/scripts/task-cli.ts complete <feature> <seq> "summary"

router.sh

#!/bin/bash
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

case "$1" in
    help|--help|-h)
        echo "Task Management Skill"
        echo "Usage: bash router.sh <command>"
        echo "Commands: status, next, blocked, complete, validate"
        ;;
    status|next|blocked|validate)
        npx ts-node "$SCRIPT_DIR/scripts/task-cli.ts" "$@"
        ;;
    complete)
        npx ts-node "$SCRIPT_DIR/scripts/task-cli.ts" "$@"
        ;;
    *)
        echo "Unknown command: $1"
        bash router.sh help
        ;;
esac

Best Practices

1. Keep Skills Focused

Each skill should do one thing well:

• ✅ Task management skill → Tracks tasks
• ❌ Task management + code generation + testing → Too broad

2. Clear Documentation

• Provide usage examples
• Document all commands
• Include expected outputs
• Explain integration points

3. Error Handling

• Handle missing arguments gracefully
• Provide helpful error messages
• Validate inputs before processing

4. Performance

• Use efficient algorithms
• Cache when appropriate
• Avoid unnecessary file operations

5. Testing

• Test all commands
• Test error conditions
• Verify integration with OpenCode

Quick Reference

File Checklist

• .opencode/skill/{skill-name}/SKILL.md created
• .opencode/skill/{skill-name}/router.sh created (if CLI-based)
• .opencode/skill/{skill-name}/scripts/skill-cli.ts created (if CLI-based)
• Router script is executable (chmod +x)
• Registry updated (if needed)
• Profile updated (if needed)
• All commands tested
• Documentation complete

Command Reference

Related Documentation

• Skills Plugin: plugins/context/capabilities/events_skills.md
• Plugin Overview: plugins/context/architecture/overview.md
• Event System: plugins/context/capabilities/events.md
• Adding Agents: guides/adding-agent.md
• Claude Code Skills: ../to-be-consumed/claude-code-docs/agent-skills.md