mcp-toolkit

MCP servers for React + TypeScript development automation. Works with Claude Desktop, Cline, Cursor — and as plain CLI scripts — one protocol, zero duplication.

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Install

Published on npm as mcp-react-toolkit. No clone or build required — run any of the 17 servers straight from npm:

npx mcp-react-toolkit --list            # list all 17 tools
npx mcp-react-toolkit legacy-analyzer   # run one as an MCP server (stdio)

Add to Claude Desktop / Cursor / Cline

// claude_desktop_config.json
{
  "mcpServers": {
    "legacy-analyzer": {
      "command": "npx",
      "args": ["-y", "mcp-react-toolkit", "legacy-analyzer"]
    },
    "component-factory": {
      "command": "npx",
      "args": ["-y", "mcp-react-toolkit", "component-factory"]
    }
  }
}

Swap in any tool name from npx mcp-react-toolkit --list. Restart your client and the tools appear.

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What's here

tools/      17 MCP server packages — each independently buildable and runnable
server/     Express bridge (port 3002) — proxies calls from the UI to MCP servers
client/     React 19 showcase SPA — tool catalog, workflow demos, animated flowcharts

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Companion package

@mcp-toolkit/code-indexer — a standalone code-intelligence engine that indexes any TS/React repo into a queryable code graph (files · components · functions, and the imports/renders/calls/references edges between them) and answers structural questions — who renders this, who calls this, find references, blast radius, cycles — over a CLI, an HTTP/WS server with a live 3D viewer, and an MCP server. Separate package, same family:

npx @mcp-toolkit/code-indexer mcp           # stdio MCP server (8 tools)
npx @mcp-toolkit/code-indexer index .       # one-shot index → .code-graph/graph.json
npx @mcp-toolkit/code-indexer query who-renders --id "cmp:src/Button.tsx#Button"

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Tools

All 17 tools are production-ready: built, tested, and CI-verified on Node 20 + 22.

Component Development

Tool	What it does	MCP tools exposed
component-factory	Scaffold React components from 41 shadcn/ui templates — with tests + Storybook	6
component-reviewer	Audit TypeScript errors, a11y issues, test coverage — graded A+ to F	3
component-fixer	Auto-fix broken imports, missing deps, inline style refactors	3
storybook-generator	Auto-generate Storybook stories — Default, variants, sizes, callbacks, play functions	2

Code Quality & Modernisation

Tool	What it does	MCP tools exposed
code-modernizer	AST-based JS/JSX → TypeScript conversion, PropTypes → interfaces	1
typescript-enforcer	Scan for any types, unsafe casts, missing modifiers — 7 rules, scored 0–10	4
accessibility-checker	WCAG 2.1 audit — alt text, label associations, ARIA roles, keyboard navigation	3
generate-tests	Analyze a TypeScript/React source file and generate a Vitest test suite	2
quality-pipeline	5-stage audit (tests · types · perf · a11y · design tokens) graded A–F	2
render-analyzer	Detect unnecessary re-renders, missing memo, inline objects/functions	3
performance-audit	Memory leaks, heavy imports, unoptimized images, deep nesting	3
test-gap-analyzer	Find unimplemented functions, uncovered branches, missing edge cases	3
legacy-analyzer	22-tool health audit for any React/Next.js/Remix app — scores 0–100, migration hints	22

Monorepo & Infrastructure

Tool	What it does	MCP tools exposed
dep-auditor	Unused deps, duplicate versions, circular imports, bundle impact analysis	4
monorepo-manager	Workspace listing, dependency graph, health check, shared dep finder	6
lighthouse-runner	Static HTML audit — meta tags, a11y, OG/Twitter cards, canonical, JSON-LD	4
json-viewer	Generate an interactive HTML JSON viewer — collapsible, searchable, dark/light	3

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Automation workflows

1 · Code Modernization

legacy-analyzer → code-modernizer → typescript-enforcer → generate-tests

Migrate a JS codebase to strict TypeScript with auto-generated test coverage.

2 · Component Quality Pipeline

component-factory → component-reviewer → accessibility-checker → storybook-generator

Generate a production-ready component, review it, fix a11y issues, and add full story coverage.

3 · Render Performance Audit

render-analyzer → performance-audit → quality-pipeline

Find unnecessary re-renders, memory leaks, and heavy imports — graded A–F.

4 · App Health Check

legacy-analyzer [analyze-legacy-app] → component-reviewer → generate-tests

Full health score (0–100) with prioritized migration hints, then fix the top issues.

5 · Dependency Health

dep-auditor [unused] → dep-auditor [duplicates] → dep-auditor [bundle-impact] → monorepo-manager

Audit and clean up a monorepo's dependency graph end-to-end.

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How MCP works

Claude Desktop / Cline / Cursor
        │
        │ JSON-RPC over stdio
        ▼
   MCP Server (e.g. typescript-enforcer)
        │
        ▼
   Tool handlers (your code)

Each server in this repo extends McpServerBase from tools/shared/ — an abstract class that handles transport, routing, and error formatting. Adding a new tool is ~50 lines.

import { McpServerBase } from '@mcp-showcase/shared';

class MyTool extends McpServerBase {
  constructor() {
    super({ name: 'my-tool', version: '1.0.0' });
  }

  protected registerTools(): void {
    this.addTool('do_thing', 'Does a thing', {
      type: 'object',
      properties: { path: { type: 'string', description: 'Target path' } },
      required: ['path'],
    }, async (args) => {
      const { path } = args as { path: string };
      return this.success({ result: `Processed ${path}` });
    });
  }
}

new MyTool().run();

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Run from source (contributors)

Prefer npm for everyday use (see Install). Clone only to hack on the tools or run the showcase UI:

git clone https://github.com/Nishant-Chaudhary5338/mcp-toolkit.git
cd mcp-toolkit
npm install
npm run build
npm test          # 450 tests across all 17 tools
npm run dev       # server on :3002, client on :5173

Point Claude Desktop at a local build

// ~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "component-factory": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/component-factory/build/index.js"]
    },
    "component-reviewer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/component-reviewer/build/index.js"]
    },
    "component-fixer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/component-fixer/build/index.js"]
    },
    "storybook-generator": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/storybook-generator/build/index.js"]
    },
    "render-analyzer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/render-analyzer/build/index.js"]
    },
    "performance-audit": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/performance-audit/build/index.js"]
    },
    "legacy-analyzer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/legacy-analyzer/build/index.js"]
    },
    "test-gap-analyzer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/test-gap-analyzer/build/index.js"]
    },
    "lighthouse-runner": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/lighthouse-runner/build/index.js"]
    },
    "dep-auditor": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/dep-auditor/build/index.js"]
    },
    "accessibility-checker": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/accessibility-checker/build/index.js"]
    },
    "generate-tests": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/generate-tests/build/index.js"]
    },
    "typescript-enforcer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/typescript-enforcer/build/index.js"]
    },
    "code-modernizer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/code-modernizer/build/index.js"]
    },
    "quality-pipeline": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/quality-pipeline/build/index.js"]
    },
    "monorepo-manager": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/monorepo-manager/build/index.js"]
    },
    "json-viewer": {
      "command": "node",
      "args": ["/path/to/mcp-toolkit/tools/json-viewer/build/index.js"]
    }
  }
}

Use as a CLI / in CI

Every tool's build/index.js has a #!/usr/bin/env node shebang and is chmod +x — pipe a JSON-RPC message to it on stdin and it writes the result to stdout.

# Analyze a full React/Next.js/Vite app — health score 0–100 + migration hints
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"analyze-legacy-app","arguments":{"path":"/path/to/app"}}}' \
  | node tools/legacy-analyzer/build/index.js

# Detect unnecessary re-renders (missing memo, inline objects)
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"detect_rerenders","arguments":{"path":"src/components"}}}' \
  | node tools/render-analyzer/build/index.js

# Audit for memory leaks and heavy imports
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"audit_bundle","arguments":{"path":"src"}}}' \
  | node tools/performance-audit/build/index.js

# Review a component — grade A+ to F
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"review","arguments":{"path":"src/components/Button.tsx"}}}' \
  | node tools/component-reviewer/build/index.js

# Auto-fix a component
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"fix","arguments":{"path":"src/components/Button.tsx"}}}' \
  | node tools/component-fixer/build/index.js

# Find untested exports
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"analyze_test_gaps","arguments":{"path":"src"}}}' \
  | node tools/test-gap-analyzer/build/index.js

# Generate Storybook stories for all components in a directory
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"generate_stories","arguments":{"path":"src/components"}}}' \
  | node tools/storybook-generator/build/index.js

# Audit an HTML file — SEO, a11y, OG tags, canonical
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"static_audit","arguments":{"path":"public/index.html"}}}' \
  | node tools/lighthouse-runner/build/index.js

# Run a WCAG audit
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"check_accessibility","arguments":{"path":"src/components"}}}' \
  | node tools/accessibility-checker/build/index.js

# Scan for TypeScript violations
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"scan_directory","arguments":{"path":"src"}}}' \
  | node tools/typescript-enforcer/build/index.js

# Find unused and outdated dependencies
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"find_unused_deps","arguments":{"root":"."}}}' \
  | node tools/dep-auditor/build/index.js

List a tool's available commands

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | node tools/legacy-analyzer/build/index.js

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Testing

Each tool has a dedicated test file covering its core logic directly — no MCP transport required.

npm test                                    # all tools
npm run test -w tools/legacy-analyzer      # single tool

Tool	Tests
render-analyzer	11
storybook-generator	20
performance-audit	15
lighthouse-runner	13
test-gap-analyzer	15
component-reviewer	19
component-fixer	10
legacy-analyzer	14
json-viewer	16
quality-pipeline	8
component-factory	6
code-modernizer	8
dep-auditor	15
accessibility-checker	15
generate-tests	14
typescript-enforcer	22
monorepo-manager	30
Total	450

CI runs on every push and PR against Node 20 and 22.

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Architecture

tools/
  shared/                McpServerBase, ToolRegistry, shared types
  component-factory/     41 shadcn/ui templates
  component-reviewer/    Review rules engine (7 categories)
  component-fixer/       Fix strategies per issue type
  storybook-generator/   Story generator (Default, variants, play functions)
  render-analyzer/       Re-render profile + memo checker
  performance-audit/     Memory leak + heavy import detector
  legacy-analyzer/       22-tool analysis engine + health scorer
  test-gap-analyzer/     Export extractor + edge case detector
  lighthouse-runner/     Static HTML auditor
  code-modernizer/       AST-based TS conversion
  quality-pipeline/      5-stage grading system
  dep-auditor/           Dependency graph analysis
  accessibility-checker/ WCAG rule engine (9 rules)
  generate-tests/        Source analyzer + test generator
  typescript-enforcer/   7-rule type safety scanner
  monorepo-manager/      Workspace operations
  json-viewer/           HTML generation

server/                  Express bridge — spawns tools as child processes
client/                  React 19 SPA — tool catalog and live demos

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Contributing

See CONTRIBUTING.md — how to scaffold a new tool, write tests, and open a PR.

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Stack

TypeScript strict · Node.js · MCP SDK 1.12 · Vitest · React 19 · Vite · Tailwind CSS · Express

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Built by

Nishant Chaudhary — Senior Frontend Engineer
nishantchaudhary.dev@gmail.com

Also see: dashcraft · react-present · ai-builder

MIT License