Byte MCP Server

PayPerByte MCP Server

A Model Context Protocol server that gives AI agents direct access to PayPerByte — per-byte USDC data feeds on Arbitrum. Agents discover feeds, subscribe to streams, or pay-per-call for one-off data via x402. Every settlement carries an EIP-712 PayloadAttestation receipt. No tokens, no API keys, no off-chain accounts: settle in USDC, route through MCP.

🧪 Testnet only. This release targets Arbitrum Sepolia (chain 421614). Use a testnet-only wallet — never configure PRIVATE_KEY to a key holding mainnet funds. Get free Sepolia ETH from any Arbitrum Sepolia faucet. Mainnet (Arbitrum One) is the next milestone, gated on the Pashov security audit.

Quick start

npx -y byte-mcp-server

Wire it into your MCP client (Claude Desktop config below), then your agent can:

• Discover feeds: "List the PayPerByte catalog" / "Search publishers for weather"
• Buy one packet (x402, no setup): "Buy the latest weather data" → ~$0.021 USDC, ~3 seconds, on-chain receipt
• Subscribe to a stream: "Subscribe me to the earthquakes feed" → auto-approves USDC for ongoing settlement
• Query a fact: "Ask the fact-oracle who won the last Lakers vs Warriors game" → on-chain signed answer with citations

The live catalog is at x402.payperbyte.io/feeds — verified, provenance-first feeds across weather, markets, code, security, and knowledge.

Two paradigms: subscribe vs. buy

Subscribe is cheaper per byte and gives the agent every broadcast; buy is zero-setup and pay-as-you-go. Pick by access pattern, not by price alone.

Tools (15 total)

Discovery (read-only, no wallet)

Subscribe to a stream (requires PRIVATE_KEY)

Buy on-demand (requires PRIVATE_KEY)

Configuration

Claude Desktop

Edit ~/.config/claude/claude_desktop_config.json (Linux) or ~/Library/Application Support/Claude/claude_desktop_config.json (macOS):

{
  "mcpServers": {
    "byte-library": {
      "command": "npx",
      "args": ["-y", "byte-mcp-server"],
      "env": {
        "PRIVATE_KEY": "0x...",
        "RPC_URL": "https://sepolia-rollup.arbitrum.io/rpc",
        "INDEXER_URL": "http://localhost:8080"
      }
    }
  }
}

PRIVATE_KEY is optional — read-only tools work without it. Add it to enable subscribe, publish, buy, and query.

Claude Code

claude mcp add byte-library -- npx -y byte-mcp-server

Environment variables

Network

Current release targets Arbitrum Sepolia (chain 421614) — PayPerByte's testnet. Mainnet (Arbitrum One) is the next milestone, gated on the external security audit. Contract addresses are pinned in the bundled config; the npm release ships ready-to-use defaults.

Development

git clone https://github.com/0rkz/byte-mcp-server.git
cd byte-mcp-server
npm install
npm run build && npm start

License

MIT — see LICENSE.

Links

• payperbyte.io — PayPerByte home
• x402.payperbyte.io/feeds — live feed catalog
• Model Context Protocol — MCP spec
• MCP TypeScript SDK