Leetcode Helper

An MCP server that gives structured, AI-powered DSA guidance inside Claude Desktop or Claude Code — approach analysis, hints, complexity breakdowns, and more, without spoiling the solution.

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Tools at a Glance

Tool	Input	What it returns
get_approach	problem	Pattern, steps, TC/SC
get_hint	problem + where stuck	Nudge, no spoilers
get_complexity	problem + code	TC/SC breakdown per block
post_solution	problem + accepted code	Discussion post ready to copy
similar_questions	problem	3–5 problems for the same pattern
upsolve	problem + working code	Optimization direction, not solution

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Setup

Prerequisites: Node.js 18+, an ANTHROPIC_API_KEY

git clone https://github.com/Navoren/leetcode-helper.git
cd leetcode-helper
npm install
npm run build

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Connect to Claude Code

Add to .claude/settings.json (project or global):

{
  "mcpServers": {
    "leetcode-helper": {
      "command": "node",
      "args": ["d:/leetcode-helper/dist/index.js"],
      "env": {
        "ANTHROPIC_API_KEY": "your-key-here"
      }
    }
  }
}

Connect to Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "leetcode-helper": {
      "command": "node",
      "args": ["/absolute/path/to/leetcode-helper/dist/index.js"],
      "env": {
        "ANTHROPIC_API_KEY": "your-key-here"
      }
    }
  }
}

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Example Usage

Getting an approach:

"Use get_approach on: Given an array of integers, return indices of two numbers that add up to target."

Getting a hint when stuck:

"Use get_hint — problem: two sum, stuck on: my nested loop works but is too slow"

Generating a discussion post:

"Use post_solution with my accepted Python solution for two sum"

Upsolving:

"Use upsolve — here's my O(n²) solution, help me think toward better"

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Project Structure

leetcode-mcp/
├── src/
│   ├── index.ts               # Entry point
│   ├── server.ts              # McpServer setup
│   ├── lib/
│   │   └── claude.ts          # Anthropic API client
│   └── tools/
│       ├── registry.ts        # Registers all tools (one line per tool)
│       ├── get_approach.ts
│       ├── get_hint.ts
│       ├── get_complexity.ts
│       ├── post_solution.ts
│       ├── similar_questions.ts
│       └── upsolve.ts
├── dist/                      # Compiled output
├── functional_requirement.md
├── technical_document.md
└── CLAUDE.md

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Adding a New Tool

1. Create src/tools/your_tool.ts — export name, description, schema (Zod), handler
2. Add one import + one entry in src/tools/registry.ts
3. npm run build

No changes to server.ts, index.ts, or claude.ts.

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Tech Stack

Layer	Choice
Runtime	Node.js (ESM)
Language	TypeScript 5
MCP SDK	@modelcontextprotocol/sdk
Schema validation	Zod
LLM	Anthropic claude-sonnet-4-6
Transport	stdio