Obol Arc MCP Server

Obol — Metered API Marketplace for AI Agents

Pay-per-call API marketplace built on Arc (Circle's USDC-native blockchain). AI agents discover services, pay in USDC, and get results — no subscriptions, no accounts, no API key management.

Live: obol-arc.web.app

What it does

• Buyers — load USDC credits, call any listed API via MCP or REST. Pay only for what you use.
• Sellers — publish any HTTPS endpoint to the marketplace. Earn USDC per call, instantly.
• Agents — discover services via find_service, pay via pay_and_call. Full MCP support.

Quick start (Claude Desktop / Cursor)

{
  "mcpServers": {
    "obol": {
      "command": "npx",
      "args": ["-y", "@superbigroach/obol-mcp"],
      "env": {
        "OBOL_AGENT_KEY": "0xYOUR_ARC_WALLET_PRIVATE_KEY"
      }
    }
  }
}

Get a funded Arc testnet wallet: sign up at obol-arc.web.app, get free USDC at faucet.circle.com.

MCP Tools

REST API

# List services
GET https://obol-arc.web.app/api/services

# Pay and call
POST https://obol-arc.web.app/api/pay-and-call
{ "apiKey": "obl_sk_live_...", "callUrl": "...", "params": {} }

# Check balance
GET https://obol-arc.web.app/api/agent-balance?apiKey=obl_sk_live_...

Hosted MCP server (HTTP/Smithery)

https://us-central1-obol-arc.cloudfunctions.net/mcpServer

Pass X-Obol-Api-Key: obl_sk_live_... header. Get a key at obol-arc.web.app/settings.

Listings

• npm: @superbigroach/obol-mcp
• Smithery: smithery.ai/servers/s-borjash/obol
• MCP Registry: io.github.superbigroach/obol

License

The Obol platform (this repo, excluding packages/) is licensed under the Elastic License 2.0 — source-available but you may not offer it as a competing hosted service. See LICENSE.

The MCP client package (packages/) is MIT licensed. See packages/LICENSE.