MCP 服务器

obol-mcp

Lets AI agents discover, pay for, and call any HTTP API per request using USDC, with gasless nanopayments and no API keys or accounts needed.

README

Obol MCP

The MCP server that lets any AI agent discover, pay for, and call APIs per request in USDC — gasless, sub-cent, no accounts, no API keys. Built on x402 + Circle Gateway.

obol-arc.web.app · Docs · Marketplace

What is Obol?

Obol is the marketplace where AI agents buy from agents. Providers list any HTTP API with a per-call price; agents discover those services and pay automatically per request in USDC.

Monetize any API — list an endpoint, set a price, get paid per call. You keep 100% (0% commission).
Gasless nanopayments — agents sign off-chain EIP-3009 authorizations (zero gas); Circle Gateway batch-settles. Payments from $0.000001.
No accounts, no API keys — the agent's wallet is its identity.
One integration unlocks the whole directory.

This package is the MCP server — add it to Claude, Cursor, or any MCP-compatible agent and it can find services, pay, and call them automatically.

Install

npx -y @superbigroach/obol-mcp

Configure (MCP client)

Add to your MCP config (e.g. Claude Desktop claude_desktop_config.json, Cursor, etc.):

{
  "mcpServers": {
    "obol": {
      "command": "npx",
      "args": ["-y", "@superbigroach/obol-mcp"],
      "env": {
        "OBOL_API_KEY": "obl_sk_live_<your-key>",
        "OBOL_AGENT_KEY": "0x<agent-wallet-private-key>"
      }
    }
  }
}

OBOL_API_KEY — get one at obol-arc.web.app/settings. Required for listing + metered calls.
OBOL_AGENT_KEY — the agent wallet's private key, used to sign gasless payment authorizations. Only needed for paying (pay_and_call); discovery and listing work without it. Fund the wallet with testnet USDC at faucet.circle.com.

Never commit your keys. Use environment variables.

Tools

Tool	What it does
`find_service`	Search the directory for an API by capability/category.
`pay_and_call`	Pay the per-call price and invoke the endpoint — gas-free.
`get_balance`	Check your USDC balance.
`deposit`	Fund your Gateway balance once for gasless spending.
`list_service`	Publish your own API to the marketplace and earn per call.

Example

You: "Find a weather API and get the forecast for New York."

Agent (via Obol MCP):
  → find_service("weather")
  → pay_and_call(weatherUrl, { lat: 40.71, lon: -74.01 })   # pays $0.001 USDC, gasless
  → "It's 29°C with 13 km/h winds in New York."

See examples/ for runnable snippets.

How payments work

An unpaid request returns HTTP 402 Payment Required with a price.
The agent signs an off-chain EIP-3009 authorization (zero gas) and retries.
The result is served immediately; Circle Gateway batch-settles on-chain.

Per-call gas is $0 because settlement is batched — that's what makes sub-cent payments viable. Read more →

Pricing

Listing is free. Obol takes 0% commission per call — sellers keep 100%.
Optional Featured / Scale subscriptions add directory visibility (never a cut of your transactions).