An MCP server that connects your AI coding assistant (Cursor, Claude Code, or any MCP-compatible host) directly to LeetCode — browse problems, get AI coaching, and submit solutions without leaving your editor.
| 🔍 | Search and read any LeetCode problem with full statement + starter code |
| 📅 | Fetch today's daily challenge |
| 💡 | Get progressive hints (5 levels — from a nudge to a near-walkthrough) |
| 🗺️ | Get a step-by-step conceptual walkthrough without being given the answer |
| 🧪 | Review your approach before you code it |
| 🐛 | Debug a failing solution with targeted feedback |
| 📊 | Analyze the time and space complexity of your code |
| 🚀 | Submit a solution and see the result inline |
| 📜 | View your full submission history |
| 👤 | See your profile and solve counts |
- Node.js 18 or later
- Cursor, Claude Code, or any MCP-compatible AI host
- A LeetCode account (free tier is fine)
1. Clone and install dependencies
git clone <your-repo-url>
cd leetcode-mcp
npm install2. Install the Chromium browser (used for the browser-based login)
npx playwright install chromium3. Build the server
npm run buildCreate or edit ~/.cursor/mcp.json:
{
"mcpServers": {
"leetcode": {
"command": "node",
"args": ["/absolute/path/to/leetcode-mcp/dist/server.js"]
}
}
}Restart Cursor. Go to Settings → Features → MCP — you should see leetcode listed with a green dot and all tools enumerated.
claude mcp add leetcode node /absolute/path/to/leetcode-mcp/dist/server.jsLeetCode requires you to be logged in. There are three ways to authenticate — browser login is the easiest and most reliable.
Just tell your AI:
"login to leetcode"
A real Chromium window opens on your screen. Log in however you normally do (email/password, Google SSO, GitHub, 2FA — it all works). The window closes automatically once the session is captured. Done.
"login to leetcode with username john@example.com and password mypassword"
With credentials provided, it tries a fast programmatic login first. If LeetCode's reCAPTCHA blocks it, the browser window opens as a fallback automatically.
If you can't open a browser (headless environment, CI, etc.):
- Log in at leetcode.com in your browser
- Open DevTools → Application → Cookies →
https://leetcode.com - Copy the values of
LEETCODE_SESSIONandcsrftoken - Tell your AI:
"set my leetcode session:
LEETCODE_SESSION = eyJ0...
csrftoken = abc123..."
Sessions last roughly 2 weeks of inactivity (longer if you visit LeetCode regularly in your browser). When yours expires, every tool will tell you clearly:
LeetCode session expired. Use set_session with fresh cookies from your browser...
To re-authenticate:
"reauth leetcode"
Same as login — browser window opens, you log in, window closes.
At any time:
"check my leetcode status"
MCP server: ✓ running
LeetCode: ✓ logged in as gokhan (session saved 5/28/2026)
Solved: 87 (E:34 M:45 H:8)
| Tool | What it does |
|---|---|
login |
Log in via browser (with optional username/password fast path) |
reauth |
Re-open browser login — use when session expires |
set_session |
Manually provide cookies (headless environments) |
logout |
Clear the saved session |
whoami |
Show your username, ranking, and solve counts |
status |
Check if the server is running and your session is valid |
"find medium array problems about sliding window"
"show me 5 easy string problems"
"search for two sum"
Returns: problem ID, title, difficulty, acceptance rate, and the slug you need for other tools.
"get the two-sum problem"
"show me merge-intervals in typescript"
"give me the daily challenge in python"
Returns: full problem statement, constraints, examples, hints, and starter code for your chosen language (or all languages if not specified).
Supported languages: python, python3, java, cpp, c, javascript, typescript, go, rust, swift, kotlin, ruby, scala, php, csharp, dart
"what's the daily challenge?"
"get today's leetcode problem in go"
These tools use your AI host's model via MCP Sampling — no API key or extra configuration needed.
"give me a hint for two-sum"
"hint level 2 for longest-substring-without-repeating-characters"
"I'm stuck on coin-change, give me a hint with my current code: [paste code]"
Five progressive levels — start at 1 and work up:
| Level | What you get |
|---|---|
| 1 | A one-line category nudge ("think about hashing") |
| 2 | Which data structure or technique applies and why |
| 3 | The key insight that makes the efficient solution possible |
| 4 | The algorithm described in plain English, step by step |
| 5 | A near-complete walkthrough with edge cases and complexity |
Tip: Start at level 1 and increment only when you're truly stuck. Jumping to 5 skips the learning.
"walk me through how to think about two-sum"
"explain step by step how to approach coin-change"
"explain the sliding window part of longest-substring-without-repeating-characters"
Covers: how to read the problem, what pattern applies, the full algorithm construction, edge cases to watch for, and complexity — zero code given.
"I want to solve two-sum by iterating through all pairs — review my approach"
"my plan for merge-intervals: sort by start time, merge overlapping ones. Is this right?"
Returns: whether your approach is correct, its complexity, edge cases you might miss, and a nudge toward a better solution if one exists — without explaining it for you.
"debug my two-sum solution in python:
[paste your code]
it fails with: Expected [0,1] but got [0,0] for input nums=[2,7,11,15], target=9"
Identifies the specific bug, explains why it causes the failure, and shows a corrected snippet for the broken section only — not a full rewrite.
"analyze the complexity of my merge-sort implementation in typescript: [paste code]"
Returns: time complexity with a trace through the loops, space complexity, whether this is optimal for the problem, and any quick performance wins.
"submit this python solution for two-sum: [paste code]"
"submit my typescript solution for merge-intervals: [paste code]"
The tool fetches the problem, verifies your language is supported, submits to LeetCode, polls until judging is done, and returns the result:
Submission ID: 1234567890
Status: Accepted
Runtime: 52 ms (beats 94.3%)
Memory: 16.4 MB
Tests: 63 / 63
Or if it fails:
Status: Wrong Answer
Tests: 42 / 63
Failing Input:
nums = [3,2,4], target = 6
Expected: [1,2]
Got: [0,1]
"check submission 1234567890"
Useful if submit_solution timed out before judging finished.
"show my recent submissions"
"show my submissions for two-sum"
"last 10 submissions for merge-intervals"
Here's a full session from problem discovery to accepted submission:
1. "what's the daily challenge in typescript?"
→ reads the problem + starter code
2. "walk me through how to think about [problem slug]"
→ conceptual walkthrough without spoilers
3. "review my approach: [describe your plan in plain English]"
→ feedback before you write a line of code
4. [write your solution in the editor]
5. "hint level 1 for [problem slug] with my current code: [paste code]"
→ if stuck, get a progressive nudge
6. "debug my [language] solution for [problem slug]:
[paste code]
error: [paste failing test]"
→ targeted bug help
7. "submit this [language] solution for [problem slug]: [paste code]"
→ submits and shows the result
8. "analyze the complexity of my solution: [paste code]"
→ learn if you can do better
The MCP server doesn't appear in Cursor
- Make sure the path in
mcp.jsonis absolute, not relative - Run
npm run buildfirst — Cursor loadsdist/server.js, not the TypeScript source - Restart Cursor after editing
mcp.json
reauth or login opens no browser window
- Run
npx playwright install chromiumto download the browser binary - Make sure you're not running in a headless-only environment (SSH without X forwarding, CI)
"Session expired" on every tool call
- Run
"reauth leetcode"— a browser will open for you to re-login
"MCP Sampling not supported" on coaching tools
- Your host doesn't support MCP sampling. Claude Code and Cursor both do. If you're using a different host, set
ANTHROPIC_API_KEYand the tools will need to be wired to call the API directly.
submit_solution returns "Language not supported"
- Use the slug form:
python3notPython 3,cppnotC++,csharpnotC# - Or call
get_problemfirst — it lists the supported language slugs for that specific problem
leetcode-mcp/
├── src/
│ ├── server.ts — MCP server entry point + all tool definitions
│ ├── auth.ts — login, browser login (Playwright), session storage
│ ├── leetcode-client.ts — LeetCode GraphQL + REST API client
│ ├── ai-helper.ts — AI coaching prompts (uses MCP sampling)
│ └── types.ts — shared TypeScript types + language slug map
├── dist/ — compiled output (run npm run build)
├── package.json
└── tsconfig.json
Session is stored at ~/.config/leetcode-mcp/session.json.
Your LeetCode session cookie is stored locally on your machine at ~/.config/leetcode-mcp/session.json. It is never sent anywhere except to LeetCode's own API. The AI coaching features use MCP sampling, which routes through your AI host (Cursor, Claude Code) — your code is not sent to any third-party service beyond what your host already does.