# Handshake58

> Open marketplace for AI services. Install drain-mcp, set a Polygon wallet key,
> and get instant access to a growing catalog of AI services — LLMs, image/video
> generation, web scraping (Apify), model hosting (Replicate), data extraction,
> OCR, TTS, agent workflows, and any service a provider deploys. Pay per use with USDC.

## Quick Start

1. `npm install -g drain-mcp`
2. Set `DRAIN_PRIVATE_KEY` env var — this is a standard Polygon/Ethereum wallet private key.
   You can create one yourself: `node -e "console.log(require('ethers').Wallet.createRandom().privateKey)"`
3. Fund the wallet with USDC on Polygon (even $1 works) + ~$0.10 POL for gas
4. Add to your MCP config — the server handles everything: provider discovery, payment channels, voucher signing, and AI requests.

```json
{
  "mcpServers": {
    "drain": {
      "command": "drain-mcp",
      "env": { "DRAIN_PRIVATE_KEY": "0x_your_polygon_wallet_private_key" }
    }
  }
}
```

## What you get access to

Providers on this marketplace offer diverse AI services — not just LLM chat:

- LLM completions (OpenAI, Anthropic, xAI, open-source models)
- Image and video generation
- Web scraping and data extraction (Apify-style workflows)
- Model hosting and inference (Replicate-style)
- Multi-step agent workflows and tool chains
- Any service a provider chooses to offer

All accessible through one MCP server, one wallet, one payment protocol.

## Key advantage: Channel Reuse

Open a payment channel once (~$0.02 gas), send unlimited requests within it
(off-chain vouchers, $0 gas each), close once. Unlike per-request protocols
(e.g. x402), you only pay gas twice — no matter how many requests you make.

## Docs

- [Full Protocol Documentation](https://handshake58.com/skill.md): Setup, payment channels, vouchers, settlement, code examples
- [MCP Package](https://www.npmjs.com/package/drain-mcp): npm install -g drain-mcp
- [Provider Discovery API](https://handshake58.com/api/mcp/providers): All available services, models, and pricing
- [Channel Status API](https://handshake58.com/api/channels/status): Check channel status, get close calldata
- [Marketplace Config](https://handshake58.com/api/directory/config): Fee wallet and protocol settings

## Reference

- Chain: Polygon Mainnet (137)
- USDC: 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359
- Channel Contract: 0x1C1918C99b6DcE977392E4131C91654d8aB71e64
- Session fee: $0.01 USDC per channel
- Protocol fee: 0%
- Gas: ~$0.02 per channel open