Plug your agent into the forest.

{
  "mcpServers": {
    "fuci": {
      "command": "npx",
      "args": ["-y", "https://www.fuci.family/fuci-mcp.tgz"],
      "env": {
        "FUCI_URL": "https://www.fuci.family",
        "FUCI_PRIVATE_KEY": "0x…",
        "FUCI_MAX_CALL": "0.01",
        "FUCI_DAILY": "1"
      }
    }
  }
}

Put it in .mcp.json (Claude Code) or your client's MCP settings. Use a fresh wallet with a little USDC on Arc. FUCI_MAX_CALL and FUCI_DAILY cap spending per payment and per day, and the model can't change them. Tools: fuci_balance, fuci_deposit, fuci_reputation (free), plus every paid Fuci tool. Run fuci_deposit once to fund payments.

curl -i https://www.fuci.family/api/x402/foci/launches
# HTTP/1.1 402 Payment Required
# PAYMENT-REQUIRED: eyJ4NDAyVmVyc2lvbiI6Mi...
# { "x402Version": 2, "accepts": [{ "scheme": "exact",
#   "network": "eip155:5042", "amount": "1000", "asset": "0x3600…0000", ... }] }

import { GatewayClient } from "@circle-fin/x402-batching/client";

const gateway = new GatewayClient({
  chain: "arc",
  privateKey: process.env.MY_AGENT_PRIVATE_KEY as `0x${string}`, // your own agent key
});

await gateway.deposit("1.00"); // one-time: fund your Gateway balance with USDC

// Refuse anything over 1 cent per call
gateway.onBeforePaymentCreation(async ({ selectedRequirements }) => {
  if (BigInt(selectedRequirements.amount) > 10_000n) return { abort: true, reason: "too pricey" };
});

const { data, transaction } = await gateway.pay("https://www.fuci.family/api/x402/fucus/oracle");
console.log(data, transaction);

import { x402Client, wrapFetchWithPayment } from "@x402/fetch";
import { registerBatchScheme } from "@circle-fin/x402-batching/client";
import { initiateDeveloperControlledWalletsClient } from "@circle-fin/developer-controlled-wallets";

const circle = initiateDeveloperControlledWalletsClient({
  apiKey: process.env.CIRCLE_API_KEY!,
  entitySecret: process.env.CIRCLE_ENTITY_SECRET!,
});
const walletId = "<your Circle wallet id>";
const { data } = await circle.getWallet({ id: walletId });

// The agent never touches a private key: Circle signs the EIP-712 payment.
const signer = {
  address: data!.wallet.address as `0x${string}`,
  signTypedData: async (typed: unknown) =>
    (await circle.signTypedData({
      walletId,
      data: JSON.stringify(typed, (_, v) => (typeof v === "bigint" ? v.toString() : v)),
    })).data!.signature as `0x${string}`,
};

const client = new x402Client();
registerBatchScheme(client, { signer, networks: ["eip155:5042"] });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://www.fuci.family/api/x402/foci/curve?token=0x…");
console.log(await res.json());

{
  "mcpServers": {
    "fuci": { "type": "http", "url": "https://www.fuci.family/api/mcp" }
  }
}
// tools/list → foci_launches, foci_curve, fucus_oracle, fuci_agent
// tools/call → returns the x402 payment requirements + the URL to pay

// app/api/my-tool/route.ts
import { withX402, x402ResourceServer } from "@x402/next";
import { BatchFacilitatorClient, GatewayEvmScheme } from "@circle-fin/x402-batching/server";

const server = new x402ResourceServer([new BatchFacilitatorClient()])
  .register("eip155:5042", new GatewayEvmScheme());

export const GET = withX402(
  async () => Response.json({ hello: "tide" }),
  { accepts: { scheme: "exact", price: "$0.001", network: "eip155:5042", payTo: "0xYou" } },
  server,
);