ToolFi — API Marketplace for AI Agents

"The next unicorn is an API marketplace for agents... where the right API should be selected by Claude and connected automatically" — @auralix4

API marketplaces exist, but they're built for human developers. ToolFi is built for AI workflows — agents discover, select, and pay for APIs automatically, without human intervention.

🌐 Website · 📡 API · 📜 Contract · 🗺️ Roadmap

The Problem

AI agents need external data (prices, security checks, routes). Current solutions:

• RapidAPI, etc. — Built for humans. Agents can't browse and click "Subscribe"
• Hardcoded keys — Security risk, doesn't scale
• Manual integration — Every new tool needs human setup

The Solution

ToolFi = APIs that agents can discover and use autonomously.

1. Discovery — Agents find tools via .well-known/mcp.json, MCP registries, semantic search
2. Selection — Rich descriptions help agents pick the right tool
3. Payment — USDC on Base, no API keys, just pay and use
4. Data — Structured responses optimized for LLM consumption

How It Works

Agent → GET /api/price?symbol=ETH
                ↓
Server → 402 Payment Required
         { toolId, price, paymentInstructions }
                ↓
Agent → USDC.approve() → Registry.payForCall(toolId)
                ↓
Agent → Retry with X-Payment-Tx header
                ↓
Server → Verify on-chain → Return data

Available Tools

Integration Options

Option 1: HTTP API (Any Agent)

# Pay on-chain, then call with payment proof
curl -H "X-Payment-Tx: 0x..." "https://toolfi.vercel.app/api/price?symbol=ETH"

Option 2: MCP Server (Claude Desktop)

cd mcp-server
uv venv && source .venv/bin/activate
uv pip install -e .

Add to Claude Desktop config:

{
  "mcpServers": {
    "toolfi": {
      "command": "/path/to/.venv/bin/python",
      "args": ["-m", "src.server"],
      "cwd": "/path/to/mcp-server"
    }
  }
}

Then ask Claude: "Check the security of token 0x... on Base"

For Tool Creators

Publish your API and earn USDC:

cast send $REGISTRY \
  "registerTool(string,string,string,uint256)" \
  "My Tool" "https://api.example.com" "Description" 10000 \
  --rpc-url https://sepolia.base.org --private-key $KEY

Price in 6 decimals: 10000 = $0.01/call

Withdraw earnings:

cast send $REGISTRY "withdraw()" --rpc-url https://sepolia.base.org

Contract

Project Structure

toolfi/
├── api/           # Vercel serverless API
├── web/           # Next.js frontend
├── mcp-server/    # Python MCP server for Claude
├── src/           # Solidity contracts
├── skill/         # OpenClaw skill spec
└── script/        # Deployment scripts

Development

# Contracts
forge build
forge test -v

# API
cd api && npm install && npm start

# MCP Server
cd mcp-server 

... [View full README on GitHub](https://github.com/Tsubaki414/toolfi#readme)