MCP 服务器

circle-agent-stack-mcp

MCP server for Circle's Agent Stack. Create wallets, set spend policies, send USDC, and pay x402-priced endpoints — all from a tool call.

README

circle-agent-stack-mcp

MCP server for Circle's Agent Stack. Create wallets, set spend policies, send USDC, and pay x402-priced endpoints — all from a tool call.

npx circle-agent-stack-mcp

Tools

Tool	What it does
`circle_wallet_create`	Create an agent wallet (dev/hosted/smart)
`circle_wallet_list`	List wallets with USDC balances
`circle_balance`	Balance + last 10 txns for a wallet
`circle_policy_set`	Set daily cap, x402 cap, allow/block lists
`circle_transfer_usdc`	Send USDC to an on-chain address
`circle_x402_pay`	Pay an x402-priced endpoint and return its response

Quickstart

You need the Circle CLI installed and authenticated:

npm install -g @circle-fin/circle-cli
circle login
export CIRCLE_API_KEY=your_key_here

Claude Desktop

{
  "mcpServers": {
    "circle": {
      "command": "npx",
      "args": ["-y", "circle-agent-stack-mcp"],
      "env": {
        "CIRCLE_API_KEY": "your_key_here"
      }
    }
  }
}

Claude Code

claude mcp add circle -- npx -y circle-agent-stack-mcp

Example

You: Create a dev wallet called eva-treasury, set a $5 daily cap and $0.10 x402 cap,
     then fetch today's BTC signal from the x402 endpoint at https://signals.example.co/btc

Claude:
→ circle_wallet_create("eva-treasury", type="dev")
  { wallet_id: "wal_abc123", address: "0x..." }

→ circle_policy_set("wal_abc123", daily_cap_usdc=5, x402_cap_usdc=0.10)
  { status: "applied" }

→ circle_x402_pay("wal_abc123", "https://signals.example.co/btc", max_price_usdc=0.10)
  { signal: "LONG", confidence: 0.72, price_paid_usdc: 0.05 }

Today's BTC signal: LONG (72% confidence). Paid $0.05.

Self-hosting with x402 paywall

http-server.ts wraps the same tools behind an x402 paywall — agents pay per call in USDC rather than using an API key. Useful if you want to expose Circle tooling as a paid service.

CIRCLE_PAYOUT_ADDRESS=0x... npm run start:http

To test the x402 flow locally, run the toy demo server in examples/x402-demo-server.mjs.

How it works

v0.1 shells out to the Circle CLI for all operations. This keeps auth handling out of this repo and avoids reimplementing the API client before the tool surface is validated. v0.2 will switch to direct HTTP via @circle-fin/circle-sdk.