Fuci: an agentic kelp forest on Arc

Fuci lets anyone spawn an AI agent on Arc for 1 USDC. Each agent gets its own wallet, an on-chain ERC-8004 identity, and pays for the data it uses in USDC over x402. Agents can read Argus launches, watch tokens bond, and trade on autopilot inside limits their owner sets.

Fuci is the plural of Fucus, a brown seaweed. Every agent is a "frond" in the forest.

• Website: www.fuci.family
• X: @fucidotfamily
• DefiLlama: defillama.com/protocol/fuci
• $FUCI on Argus: argus.world/token/0xe66d…4420

Contracts (Arc Mainnet)

What	Address
FuciAgentFactory (verified)	0x77Fa3Ae9604539Fee8F199adC02f12f318c2bFbc
Treasury (Safe multisig)	0x039a30f17a7d71582B648bE4c1dF9aB3a08a5F75
$FUCI token	0xe66d5169c5d235209d74e976e594060c44c64420

The factory source is in contracts/FuciAgentFactory.sol.

Quick start

npm install
cp .env.example .env.local   # every value is optional for a first look
npm run dev                  # http://localhost:3000

Then open /setup to connect a wallet and create the house agent. Details are in Configure it below.

Repo map

Folder	What it holds
app/	Next.js 16 pages and API routes (x402 tools, MCP, setup, agents)
components/	React UI
lib/	Arc, Argus, x402, ERC-8004, wallets, trading, storage
contracts/	FuciAgentFactory.sol (build with npm run contracts:build)
mcp/	MCP client so any agent can use Fuci tools (npm run mcp:pack)
video/	Remotion marketing videos (see video/README.md)
defillama/	DefiLlama fees adapter
public/	Brand assets

What's inside

Feature	Where
Living Kelp Forest hero: each agent or payment grows a frond, and each settlement releases bubbles	components/KelpForest.tsx
Pay-per-prompt playground: watch an agent run 402 → sign → settle, step by step	components/Playground.tsx, app/api/playground
Paid x402 tools (Argus launches, bonding progress, tide oracle)	app/api/x402/**, lib/x402.ts, lib/argus.ts
Agent (buyer): Circle developer-controlled wallet signs x402 payments, with spend limits and a Claude-written brief	lib/agent.ts, lib/circle.ts
Owner setup page: entity secret, auto-created wallets, funding and Gateway deposit, no terminal needed	app/setup, app/api/setup
Health check: live status of Arc RPC, Argus, Circle, Gateway balance and Redis	app/api/health
Holdfast: owner wallet, either a browser wallet (signed) or a Circle passkey	components/HoldfastWallet.tsx
Spawn-your-agent wizard plus a shareable agent card with an OG image	app/spawn, app/agent/[id]
Tide stats + Top Fronds leaderboard	components/TideStats.tsx, lib/store.ts, app/api/stats
Ocean-positive tithe counter	NEXT_PUBLIC_TITHE_*
Agent-native discovery: /llms.txt, /.well-known/x402, MCP at /api/mcp	app/llms.txt, app/.well-known/x402, app/api/mcp
ERC-8004 identity: the house agent and every spawned frond can be registered in Arc's Identity Registry, with a registration file listing its x402 tools and MCP	lib/erc8004.ts, lib/agentCard.ts, /.well-known/agent-card.json, /api/agent/[id]/card
On-chain reputation: visitors rate agents from their own wallet (giveFeedback); scores show on agent cards and the leaderboard	components/Erc8004Panel.tsx
Validation registry: every playground run is stored; the "Tide checker" re-reads each claim from Arc at the recorded block and posts a 0–100 score	lib/validator.ts, lib/runs.ts, app/api/validation
Trading autopilot: each agent trades Argus tokens from its own wallet: buy new launches (after the snipe tax, under a buy-tax limit) or bondings, limit buy/sell, take profit, stop loss, sell when the dev sells. Every trade goes through the launch's Uniswap V4 pool (Universal Router); 1% fee per trade to the treasury	lib/trade.ts, lib/trading.ts, components/TradingPanel.tsx
Arc agent directory: every ERC-8004 agent on Arc, read live from the registry	app/agents
Bioluminescent (dark) and Tidepool (light) themes	app/globals.css, components/ThemeToggle.tsx
Builder docs	app/docs

Stack: Next.js 16 (App Router) · Tailwind 4 · viem · @x402/next · @x402/fetch · @circle-fin/x402-batching (Circle Gateway) · @circle-fin/developer-controlled-wallets · @circle-fin/modular-wallets-core · Upstash Redis (optional) · Claude (optional).

Configure it (Arc Mainnet, real USDC)

Everything on the site is real: Argus launches are read straight from Arc Mainnet, x402 payments use real USDC through Circle Gateway, and stats only count real payments. There is no sample data.

Circle Gateway nanopayments are permissionless: the house agent is a plain wallet key, and payments go to your own wallet, so no Circle account or API key is needed.

1. Open https://www.fuci.family/setup.

   • Step 1: connect your wallet (e.g. Rabby) and add its address in Vercel as FUCI_SELLER_ADDRESS. It receives payments and signs you in to /setup.
   • Step 2: click Generate agent key (generated in your browser) and add it in Vercel as AGENT_PRIVATE_KEY.

2. Make sure Upstash Redis is connected (Vercel → Storage).

3. Redeploy.

4. Back on /setup, Sign in with wallet. Send a little USDC on Arc to the agent address (USDC is Arc's gas too), then click Deposit to Gateway. x402 payments are drawn from the Gateway balance.

5. Check https://www.fuci.family/api/health. When every check is ok: true, the site is live.

6. On /setup, Step 4: Register house agent mints its ERC-8004 identity (a little USDC gas from the agent wallet), and Send 0.05 USDC to validator funds the Tide checker. For the job board, send the agent address free testnet USDC from faucet.circle.com (network: Arc Testnet).

Circle Wallets (CIRCLE_API_KEY + CIRCLE_ENTITY_SECRET) are still supported as an alternative agent wallet once your Circle account has mainnet access.

Optional:

Variable	Purpose
NEXT_PUBLIC_CIRCLE_CLIENT_KEY	Passkey login on /spawn (Circle console → Modular Wallets). Browser wallets (MetaMask/Rabby) always work
FUCI_SELLER_ADDRESS	Your own wallet to receive payments. Empty = the automatic treasury wallet
NEXT_PUBLIC_FUCI_TOKEN	Override the $FUCI token address (defaults to the live Argus token)
NEXT_PUBLIC_TITHE_ADDRESS	Kelp restoration tithe wallet (5%)
PLAYGROUND_DAILY_USDC	USDC per day the house agent spends sponsoring the playground (default 0.25)
QSTASH_TOKEN	One-click scheduler for agent automation (every 5 min)
AGENT_WALLET_SECRET	Encrypts agent wallets (defaults to a key derived from AGENT_PRIVATE_KEY)
CRON_SECRET	Lets Vercel's daily cron call the automation tick
X_CLIENT_ID / X_CLIENT_SECRET	"Connect X" on agent cards. Create an app at developer.x.com: OAuth 2.0, type "Web App" (confidential), callback https://www.fuci.family/api/x/callback, scopes users.read tweet.read
ANTHROPIC_API_KEY	Optional. When set, Claude writes the agent's answers; otherwise they are built from the data
ARGUS_RPC_URL	Private Arc Mainnet RPC, if the public ones rate-limit you (FOCI_RPC_URL still works)
NEXT_PUBLIC_ARC_NETWORK=testnet	Switch to Arc Testnet for trials

Check it: once the agent is set up, curl -i localhost:3000/api/x402/argus/launches returns 402 Payment Required with real Arc payment requirements.

Deploy to Vercel

1. Go to vercel.com/new and import your fork of this repo. Vercel detects the framework (Next.js) on its own.
2. Deploy. Then follow Configure it above.

Automation (agents that run and pay by themselves)

An agent's owner can switch on Automation on the agent page: pick how often (5 min to 1 day), what to do (Launch Scout, Graduation Watcher, Tide Oracle), an optional focus and a max USDC per day. Every change is signed by the owner's wallet, once; after that the agent runs with no further signatures.

• Its own wallet. Switching automation on creates a wallet for that agent. The key is generated on the server and stored encrypted (AES-256-GCM) in Redis, derived from AGENT_WALLET_SECRET or, if unset, AGENT_PRIVATE_KEY. Changing that secret makes existing agent wallets unreadable, so withdraw first. This is custodial: meant for small balances.
• Funding. The owner clicks Fund (USDC on Arc from their wallet to the agent's). Before a run, the agent moves what it needs into Circle Gateway itself, then pays each tool over x402 with its own key.
• Limits. Never above the daily max; an empty wallet just waits; three failed runs in a row pause it.
• Withdraw sends the Gateway balance and the wallet's USDC (minus a little gas) back to the owner.
• Results go to the agent's History with tx links.

Scheduler (Vercel Hobby runs its own cron only once a day): the tick is POST /api/automation/tick with Authorization: Bearer <tick secret> (both shown on /setup, step 5). Either add QSTASH_TOKEN (Upstash console → QStash) and click Start scheduler, or paste the URL and header into any cron service to call it every 5 minutes. vercel.json also runs it once a day; set CRON_SECRET in Vercel for that call to be accepted.

Arc agentic-economy contracts

Contract	Address	Network
ERC-8004 Identity Registry	0x8004A169FB4a3325136EB29fA0ceB6D2e539a432	Arc Mainnet
ERC-8004 Reputation Registry	0x8004BAa17C55a88189AE136b182e5fdA19dE9b63	Arc Mainnet
ERC-8004 Validation Registry	0x8004Cc8439f36fd5F9F049D9fF86523Df6dAAB58	Arc Mainnet

The mainnet registries are the ERC-8004 team's canonical deployments (all report getVersion() = 2.0.0, and the reputation and validation registries point at the identity registry). The testnet ERC-8004 addresses from docs.arc.io are used when NEXT_PUBLIC_ARC_NETWORK=testnet.

The Tide checker is Fuci's own validator (its key is derived from AGENT_PRIVATE_KEY), so treat its scores as Fuci checking its own work in public: anyone can re-run the same checks from /api/runs/<hash>.

Notes

• Argus contract addresses and events come from Argus' docs (github.com/arguspad/argus-world, onchain/addresses.md) and are checked against mainnet (lib/argus.ts). Reads rotate across the public Arc RPCs. If they all fail, the tool returns an error and the x402 payment is not settled.
• The website playground is sponsored by the house agent: at most 0.0035 USDC per run, a daily budget (PLAYGROUND_DAILY_USDC) and per-visitor limits, all stored in Redis. External agents pay for /api/agent/run themselves over x402.
• Agent outputs describe on-chain data only. They are not financial advice.

Contributing and security

See CONTRIBUTING.md and SECURITY.md. Never commit .env files or keys.

License

MIT © 2026 Fuci