my-skill

title	Creating Plugins
order	2

Creating Plugins

This guide walks through creating a new plugin for Uniswap AI.

Prerequisites

• Familiarity with the monorepo structure
• Understanding of skills and evals
• Development environment set up per Contributing Guide

Step 1: Create Plugin Structure

# Create plugin directory
mkdir -p packages/plugins/my-plugin/.claude-plugin
mkdir -p packages/plugins/my-plugin/skills

Step 2: Create Plugin Manifest

Create .claude-plugin/plugin.json:

{
  "name": "my-plugin",
  "version": "0.1.0",
  "description": "Description of what your plugin does",
  "author": {
    "name": "Your Name",
    "email": "[e-mail]"
  },
  "license": "MIT",
  "skills": []
}

Step 3: Create Package Configuration

Create package.json:

{
  "name": "@uniswap/my-plugin",
  "version": "0.1.0",
  "private": true,
  "description": "My Uniswap AI plugin",
  "license": "MIT",
  "repository": {
    "type": "git",
    "url": "https://github.com/Uniswap/uniswap-ai.git",
    "directory": "packages/plugins/my-plugin"
  }
}

Create project.json for Nx:

{
  "name": "my-plugin",
  "$schema": "../../../node_modules/nx/schemas/project-schema.json",
  "projectType": "library",
  "targets": {}
}

Step 4: Create a Skill

Create skills/my-skill/SKILL.md:

---
name: my-skill
description: Brief description of the skill
license: MIT
metadata:
  author: uniswap
---

# My Skill

## Overview

Describe what this skill does and when to use it.

## Instructions

Provide detailed instructions for the AI on how to perform this skill.

### Step 1: Gather Information

Ask the user for necessary context...

### Step 2: Perform Action

Based on the information, do the following...

## Examples

### Example 1: Basic Usage

User: "I want to do X"

The AI should respond by...

## References

- [Relevant Documentation](https://example.com)

Update plugin.json to include the skill:

{
  "skills": ["./skills/my-skill"]
}

Step 5: Create Eval Suite

Every skill needs an evaluation suite:

mkdir -p evals/suites/my-skill/cases
mkdir -p evals/suites/my-skill/rubrics

Create evals/suites/my-skill/prompt-wrapper.txt:

You are an AI assistant with the following skill loaded. Follow its instructions
precisely when responding to the user's request.

{{ skill_content }}

---

User request:

{{ case_content }}

Create evals/suites/my-skill/promptfoo.yaml:

# yaml-language-server: $schema=https://promptfoo.dev/config-schema.json
description: 'My Skill Evaluation'

prompts:
  - file://prompt-wrapper.txt

providers:
  - id: anthropic:claude-sonnet-4-5-20250929
    config:
      temperature: 0
      max_tokens: 4096

defaultTest:
  options:
    timeout: 120000
  vars:
    skill_content: file://../../../packages/plugins/my-plugin/skills/my-skill/SKILL.md

tests:
  - vars:
      case_content: file://cases/basic.md
    assert:
      - type: llm-rubric
        value: file://rubrics/correctness.txt
        threshold: 0.8
        provider: anthropic:claude-sonnet-4-5-20250929

Create a test case in evals/suites/my-skill/cases/basic.md and rubrics in evals/suites/my-skill/rubrics/. See Writing Evals for detailed guidance.

Step 6: Create README

Create README.md:

# My Plugin

Description of what the plugin provides.

## Installation

\`\`\`bash
/plugin install my-plugin
\`\`\`

## Skills

### /my-skill

Description of the skill.

## Usage

Examples of how to use the plugin.

Step 7: Register in Marketplace

Add your plugin to .claude-plugin/marketplace.json:

{
  "plugins": [
    {
      "name": "my-plugin",
      "source": "./packages/plugins/my-plugin",
      "description": "Description of what your plugin does"
    }
  ]
}

Step 8: Validate

Run plugin validation:

node scripts/validate-plugin.cjs packages/plugins/my-plugin

Testing Your Plugin

Local Testing

1. Install the plugin locally in Claude Code
2. Test each skill manually
3. Verify expected behavior

Running Evals

# Run your skill's evals
npx nx run evals:eval --suite=my-skill

Best Practices

Skill Design

• Keep skills focused on a single task
• Provide clear, step-by-step instructions
• Include examples for common use cases
• Reference external documentation when needed

Agent-Agnostic Design

• Write prompts that work across different LLMs
• Avoid model-specific features unless necessary
• Use standard markdown formatting
• Document any model-specific requirements

Documentation

• Keep README.md up to date
• Document all skills and their invocations
• Include usage examples
• Link to relevant resources

Troubleshooting

Plugin Validation Fails

Check that:

• plugin.json is valid JSON
• All referenced skills/agents exist
• Version numbers match between files

Eval Coverage Check Fails

Ensure:

• Eval suite exists in evals/suites/
• promptfoo.yaml is properly configured
• At least one test case exists

Related

• Plugins Overview - Plugin architecture
• Writing Evals - Creating evaluations
• Contributing - Contribution guidelines