https://github.com/wintyx57/x402-backend

API marketplace powered by HTTP 402 protocol — AI agents pay per call with USDC on Base. 69 native endpoints, on-chain payment verification, multi-chain (Base + SKALE).
https://github.com/wintyx57/x402-backend
ai-agents api-marketplace base crypto-payments express http-402 mcp-server usdc web3 x402
Last synced: 3 months ago
JSON representation
API marketplace powered by HTTP 402 protocol — AI agents pay per call with USDC on Base. 69 native endpoints, on-chain payment verification, multi-chain (Base + SKALE).
Host: GitHub
URL: https://github.com/wintyx57/x402-backend
Owner: Wintyx57
License: mit
Created: 2026-02-06T20:16:34.000Z (4 months ago)
Default Branch: main
Last Pushed: 2026-02-28T17:42:47.000Z (3 months ago)
Last Synced: 2026-02-28T19:42:40.283Z (3 months ago)
Topics: ai-agents, api-marketplace, base, crypto-payments, express, http-402, mcp-server, usdc, web3, x402
Language: JavaScript
Homepage: https://x402bazaar.org
Size: 579 KB
Stars: 0
Watchers: 0
Forks: 0
Open Issues: 0
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Awesome Lists containing this project

README

          


  
x402 Bazaar

  

    The decentralized API marketplace where AI agents pay with USDC, not API keys.

  

  

    

    

    

    

    

  


![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg) ![Node.js](https://img.shields.io/badge/node-%3E%3D18-brightgreen) ![Tests](https://img.shields.io/badge/tests-478%20passing-brightgreen) ![Render](https://img.shields.io/badge/deploy-Render-46E3B7) ![APIs](https://img.shields.io/badge/APIs-69%20native-blue)

---

## Ecosystem

| Repository | Description |

|------------|-------------|

| **[x402-backend](https://github.com/Wintyx57/x402-backend)** (this repo) | Backend API — Express server, payment middleware, 69 native wrappers, MCP server |

| **[x402-frontend](https://github.com/Wintyx57/x402-frontend)** | React frontend — 15 pages, glassmorphism UI, wallet connect, i18n FR/EN |

| **[x402-langchain](https://github.com/Wintyx57/x402-langchain)** | Python package — LangChain tools for x402 Bazaar (pip install) |

| **[x402-fast-monetization-template](https://github.com/Wintyx57/x402-fast-monetization-template)** | FastAPI template — Monetize any Python function with x402 in 5 minutes |

| **[CLI: npx x402-bazaar](https://www.npmjs.com/package/x402-bazaar)** | One-line setup for Claude Desktop, Cursor, VS Code |

| **[@x402/sdk](https://www.npmjs.com/package/@x402/sdk)** | TypeScript SDK — typed client for x402 Bazaar APIs |

| **[Reviews API](https://x402-api.onrender.com/api/reviews)** | Ratings & reviews system for marketplace services |

| **[Bazaar Discovery](https://x402-api.onrender.com/api/discovery)** | Agent discovery via @x402/extensions v2.5.0 (official Coinbase SDK) |

**Live:** [x402bazaar.org](https://x402bazaar.org) | **API:** [x402-api.onrender.com](https://x402-api.onrender.com) | **Dashboard:** [x402-api.onrender.com/dashboard](https://x402-api.onrender.com/dashboard)

---

## What is x402 Bazaar?

x402 Bazaar is an autonomous API marketplace built on the [HTTP 402 Payment Required](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/402) standard. AI agents discover services, pay in USDC on Base or SKALE Europa (zero gas), and get instant access -- no API keys, no subscriptions, no accounts. The server verifies payments on-chain and enforces anti-replay protection, making every transaction trustless and permissionless.

## Key Features

- **HTTP 402 Protocol** -- Standard-compliant payment flow. Call an endpoint, get a `402` with payment details, pay USDC, retry with tx hash, done.

- **69 Native API Wrappers** -- Web search, URL scraper, Twitter/X, weather, crypto, jokes, DALL-E 3, translation, code execution, sentiment analysis, and 59+ more -- all behind micropayments.

- **70+ Registered Services** -- Growing marketplace of third-party APIs monetized through x402.

- **LangChain Integration** -- Python package `x402-langchain` for agents built with LangChain/LangGraph.

- **Multi-Chain** -- Base (mainnet) + SKALE Europa (zero gas fees via sFUEL).

- **MCP Server** -- Plug into Claude Desktop, Cursor, VS Code, or Claude Code as native AI tools.

- **One-Line Setup** -- `npx x402-bazaar init` detects your IDE and configures everything.

- **Anti-Replay Protection** -- Every transaction hash is stored in Supabase and can only be used once.

- **Budget Control** -- Per-session spending caps for AI agents (configurable `MAX_BUDGET_USDC`).

- **Security Hardened** -- Helmet headers, CORS whitelist, rate limiting (3 tiers), input sanitization, SSRF protection.

- **478 Tests** -- 14 test suites, all passing (node:test, zero deps).

- **Real-Time Monitoring** -- 69 endpoints checked every 5min, Telegram alerts on transitions, public `/api/status` page.

- **Telegram Bot** -- Interactive admin bot with 6 commands (/balance, /stats, /status, /recent, /services, /help).

- **Auto-Test on Registration** -- New services are pinged automatically, with Telegram notification on result.

- **Public Stats** -- `GET /api/public-stats` (no auth) for frontend homepage counters.

## Quick Start

```bash

# One-line setup for AI IDEs (Claude Desktop, Cursor, VS Code)

npx x402-bazaar init

```

Or run the server locally:

```bash

git clone https://github.com/Wintyx57/x402-backend.git

cd x402-backend

npm install

cp .env.example .env   # Fill in your keys

node server.js

```

## How the x402 Payment Flow Works

```

Agent                          x402 Bazaar                     Base / SKALE

  |                                |                                |

  |  GET /api/weather?city=Paris   |                                |

  |------------------------------->|                                |

  |  402 Payment Required          |                                |

  |  { amount: 0.02, recipient }   |                                |

  |<-------------------------------|                                |

  |                                |                                |

  |  Transfer 0.02 USDC ------------------------------------------>|

  |  tx: 0xabc123...              |                                |

  |                                |                                |

  |  GET /api/weather?city=Paris   |                                |

  |  X-Payment-TxHash: 0xabc123   |                                |

  |------------------------------->|                                |

  |                                |  verify tx on-chain ---------->|

  |                                |  mark tx used (anti-replay)    |

  |  200 OK { temperature: 15.2 } |                                |

  |<-------------------------------|                                |

```

## API Reference

### Marketplace Endpoints

| Route | Method | Cost | Description |

|-------|--------|------|-------------|

| `/` | GET | Free | Marketplace info + endpoint catalog |

| `/health` | GET | Free | Health check + supported networks |

| `/services` | GET | 0.05 USDC | List all registered services |

| `/search?q=` | GET | 0.05 USDC | Search services by keyword |

| `/register` | POST | 1.00 USDC | Register a new service |

### Native API Wrappers (69 endpoints, x402-powered)

| Route | Cost | Source | Description |

|-------|------|--------|-------------|

| `/api/search?q=` | 0.005 USDC | DuckDuckGo | Clean web search results for LLMs |

| `/api/scrape?url=` | 0.005 USDC | Cheerio + Turndown | Any URL to clean Markdown |

| `/api/twitter?user=\|tweet=\|search=` | 0.005 USDC | fxtwitter | Twitter/X profiles, tweets, search |

| `/api/weather?city=` | 0.02 USDC | Open-Meteo | Weather data for any city |

| `/api/crypto?coin=` | 0.02 USDC | CoinGecko | Cryptocurrency prices (USD/EUR) |

| `/api/joke` | 0.01 USDC | Official Joke API | Random joke |

| `/api/image?prompt=` | 0.05 USDC | DALL-E 3 | AI image generation (1024x1024) |

| `/api/wikipedia?q=` | 0.005 USDC | Wikipedia API | Article summaries |

| `/api/dictionary?word=` | 0.005 USDC | Free Dictionary | English definitions |

| `/api/countries?name=` | 0.005 USDC | REST Countries | Country data |

| `/api/github?user=\|repo=` | 0.005 USDC | GitHub API | Profiles and repo stats |

| `/api/npm?package=` | 0.005 USDC | NPM Registry | Package metadata |

| `/api/ip?address=` | 0.005 USDC | ip-api.com | IP geolocation |

| `/api/translate?text=&to=` | 0.005 USDC | MyMemory | Translate 90+ languages |

| `/api/summarize?text=` | 0.01 USDC | GPT-4o-mini | AI text summarization |

| `/api/code` | 0.005 USDC | Piston API | Execute code in 50+ languages |

| `/api/sentiment?text=` | 0.005 USDC | GPT-4o-mini | Sentiment analysis |

| `/api/dns?domain=` | 0.003 USDC | Node DNS | DNS record lookup |

| `/api/currency?from=&to=` | 0.005 USDC | Frankfurter | Currency conversion (ECB) |

| ...and 22 more | 0.003-0.005 | Various | See [API_WRAPPERS.md](API_WRAPPERS.md) |

### Monitoring & Status (Free)

| Route | Description |

|-------|-------------|

| `/api/status` | Live monitoring status for all 69 endpoints |

| `/api/status/uptime` | Uptime percentages by endpoint |

| `/api/status/history` | Check history (last 24h) |

| `/api/public-stats` | Public stats (services, API calls, monitoring, integrations) |

### Dashboard (Admin, requires `X-Admin-Token`)

| Route | Description |

|-------|-------------|

| `/dashboard` | Admin UI -- stats, services, activity log, System Info |

| `/api/stats` | JSON stats (services, payments, revenue, wallet balance) |

| `/api/analytics` | Enriched analytics (balance, recent activity, avg price) |

### Payment Headers

| Header | Required | Description |

|--------|----------|-------------|

| `X-Payment-TxHash` | Yes (for paid endpoints) | USDC transfer transaction hash |

| `X-Payment-Chain` | No (default: `base`) | Chain used: `base`, `base-sepolia`, or `skale` |

## MCP Server

The MCP server exposes x402 Bazaar as native tools for AI IDEs. Agents can discover, search, and pay for APIs directly from their conversation.

```bash

npx x402-bazaar init   # Auto-detects your IDE and installs

```

### MCP Tools

| Tool | Cost | Description |

|------|------|-------------|

| `discover_marketplace` | Free | Browse available endpoints and service count |

| `search_services` | 0.05 USDC | Search APIs by keyword |

| `list_services` | 0.05 USDC | Full service catalog |

| `find_tool_for_task` | 0.05 USDC | Describe what you need in plain English, get the best match |

| `call_api` | Free | Call any external API URL |

| `get_wallet_balance` | Free | Check agent wallet USDC balance on-chain |

| `get_budget_status` | Free | Session spending tracker |

## Supported Networks

| Network | Chain ID | Gas | USDC Contract |

|---------|----------|-----|---------------|

| Base | 8453 | ~$0.001 | `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` |

| Base Sepolia | 84532 | Free (testnet) | `0x036CbD53842c5426634e7929541eC2318f3dCF7e` |

| SKALE Europa | 2046399126 | Free (sFUEL) | `0x5F795bb52dAc3085f578f4877D450e2929D2F13d` |

## Tech Stack

| Layer | Technology |

|-------|-----------|

| Runtime | Node.js |

| Framework | Express 5 |

| Blockchain | Base + SKALE Europa (USDC) |

| Wallet SDK | Coinbase Developer Platform (CDP) |

| Database | Supabase (PostgreSQL) |

| MCP | Model Context Protocol SDK |

| AI (demo) | OpenAI GPT-4o-mini |

| Scraping | Cheerio + Turndown |

## Environment Variables

| Variable | Description |

|----------|-------------|

| `PORT` | Server port (default: 3000) |

| `NETWORK` | `mainnet` or `testnet` |

| `WALLET_ADDRESS` | USDC recipient address |

| `WALLET_ID` | Coinbase CDP wallet ID |

| `COINBASE_API_KEY` | Coinbase Developer Platform API key |

| `COINBASE_API_SECRET` | CDP API secret |

| `SUPABASE_URL` | Supabase project URL |

| `SUPABASE_KEY` | Supabase anon key |

| `OPENAI_API_KEY` | OpenAI key (for /api/image, /api/summarize, /api/sentiment) |

| `ADMIN_TOKEN` | Secret token for dashboard access |

| `TELEGRAM_BOT_TOKEN` | Telegram bot token for monitoring alerts + interactive commands |

| `TELEGRAM_CHAT_ID` | Telegram chat ID to receive notifications |

## Scripts

```bash

npm start            # Start the server

npm run mcp          # Start the MCP server

npm run seed         # Seed 75+ services into Supabase

npm run seed:wrappers # Register the 69 native wrappers

npm run demo         # Run the autonomous agent demo

npm run demo:live    # Hackathon live demo with terminal UI

```

## Security

- **Helmet** -- Security headers (HSTS, X-Content-Type, X-Frame-Options)

- **CORS** -- Strict origin whitelist (no wildcards in production)

- **Rate Limiting** -- 3 tiers: general (500/15min), paid endpoints (30/min), registration (10/hr)

- **Anti-Replay** -- Transaction hashes persisted in Supabase `used_transactions` table

- **On-Chain Verification** -- Validates USDC transfer logs directly via RPC

- **USDC-Only** -- Rejects non-USDC token transfers

- **Input Sanitization** -- Control character rejection, Postgres LIKE escaping, length limits

- **SSRF Protection** -- Blocks localhost, private IPs, IPv6 loopback, cloud metadata

- **Body Limit** -- 10KB max request body

- **RPC Timeout** -- 10s timeout on all blockchain calls

## Create Your Own x402 API

Monetize any Python function in 5 minutes with the FastAPI template:

```bash

git clone https://github.com/Wintyx57/x402-fast-monetization-template

cd x402-fast-monetization-template

pip install -r requirements.txt

cp .env.example .env  # Set your WALLET_ADDRESS

python main.py

```

```python

@x402_paywall(price=0.05, description="My API", tags=["cool"])

def my_function(text: str) -> dict:

    return {"result": "something"}

```

## Contributing

Contributions are welcome. Please open an issue to discuss proposed changes before submitting a PR.

1. Fork the repository

2. Create your feature branch (`git checkout -b feature/amazing-feature`)

3. Commit your changes (`git commit -m 'Add amazing feature'`)

4. Push to the branch (`git push origin feature/amazing-feature`)

5. Open a Pull Request

## Links

- **Website:** [x402bazaar.org](https://x402bazaar.org)

- **Frontend:** [github.com/Wintyx57/x402-frontend](https://github.com/Wintyx57/x402-frontend)

- **LangChain:** [github.com/Wintyx57/x402-langchain](https://github.com/Wintyx57/x402-langchain)

- **CLI:** `npx x402-bazaar init` | [npm](https://www.npmjs.com/package/x402-bazaar)

- **API Template:** [x402-fast-monetization-template](https://github.com/Wintyx57/x402-fast-monetization-template)

- **Live API:** [x402-api.onrender.com](https://x402-api.onrender.com)

- **Dashboard:** [x402-api.onrender.com/dashboard](https://x402-api.onrender.com/dashboard)

## License

MIT
ecosyste.ms

Data

Tools

Indexes

Applications

Experiments

Awesome

https://github.com/wintyx57/x402-backend

Awesome Lists containing this project

README

x402 Bazaar
