add-tool-plugin - SKILL.md Agent Skill

name: add-tool-plugin description: Add support for a new AI coding tool

Add Tool Plugin

Guide for adding LNAI support for a new AI coding tool.

Overview

Each plugin implements the Plugin interface to transform unified .ai/ config into a tool's native format.

Before You Start

Search the official documentation for the target tool to understand its configuration format:

What config files does it use?
What file formats are supported (JSON, YAML, Markdown)?
Where should config files be placed?
What features does it support (rules, MCP, settings)?

Steps

1. Add Tool ID

Update packages/core/src/constants.ts:

Add tool ID to TOOL_IDS array (e.g., "newtool")
Add output directory to TOOL_OUTPUT_DIRS map
Add override directory to OVERRIDE_DIRS map

2. Create Plugin Directory

Create packages/core/src/plugins/<tool-name>/:

<tool-name>/
├── index.ts          # Plugin implementation
├── types.ts          # Tool-specific types (optional)
├── transforms.ts     # Transformation functions (optional)
└── index.test.ts     # Tests

3. Implement Plugin Interface

In index.ts, implement the Plugin interface:

import type { Plugin } from "../types";
import type { OutputFile, UnifiedState, ValidationResult } from "../../types";
import { applyFileOverrides } from "../../utils/transforms";

export const newToolPlugin: Plugin = {
  id: "newtool",
  name: "New Tool",

  async detect(rootDir: string): Promise<boolean> {
    // Check if tool's config exists
    return false;
  },

  async import(rootDir: string): Promise<Partial<UnifiedState> | null> {
    // Import existing config to unified format
    return null;
  },

  async export(state: UnifiedState, rootDir: string): Promise<OutputFile[]> {
    const files: OutputFile[] = [];

    // Add AGENTS.md symlink
    if (state.agents) {
      files.push({
        path: ".newtool/AGENTS.md",
        type: "symlink",
        target: "../.ai/AGENTS.md",
      });
    }

    // Add rules, settings, MCP servers...

    return applyFileOverrides(files, rootDir, "newtool");
  },

  validate(state: UnifiedState): ValidationResult {
    const warnings: ValidationWarningDetail[] = [];
    const skipped: SkippedFeatureDetail[] = [];

    // Add warnings for unsupported features

    return { valid: true, errors: [], warnings, skipped };
  },
};

4. Register Plugin

In packages/core/src/plugins/index.ts:

import { newToolPlugin } from "./newtool/index";
pluginRegistry.register(newToolPlugin);

5. Add Tests

Create index.test.ts with tests for export() and validate().

6. Add Documentation

Create apps/docs/src/content/docs/tools/<tool-name>.md documenting:

Tool overview
Supported features
Output format
Any limitations

7. Run Quality Checks

pnpm lint && pnpm typecheck && pnpm test

Key Concepts

OutputFile types: "symlink", "json", "text"
applyFileOverrides(): Apply user overrides from .ai/.<tool>/
ValidationResult: Return warnings/skipped for unsupported features

Reference Documentation

When implementing, refer to:

Existing plugins in packages/core/src/plugins/ as examples
The Plugin interface in packages/core/src/plugins/types.ts
Transform utilities in packages/core/src/utils/transforms.ts