agent-examples

Yeetful's fleet of x402 payer agents — the mirror image of x402-services (the payees). One repo, many thin agents, each with a Yeetful expense account: an allowlist of payable hosts plus per-call / per-day USD caps, with a receipt for every decision (settlement or denial). Agents pay per call in USDC on Base — no API keys to the data they buy.

packages/agent-kit/      shared payer plumbing: viem wallet from env + the yeetful() expense account + receipt log
agents/coinbase/         a Coinbase trading agent → reads its portfolio, places order-book trades,
                         and pays x402 for the market signal it trades on   → next.js app

x402-services owns the payment gate (a service is a thin adapter over @yeetful/x402-service-kit). This repo owns the payer — an agent is a thin adapter over @yeetful/agent-kit, which wraps the published yeetful SDK's yeetful({ wallet, grant }) expense account so the spend-control wiring is one place, not N agents.

The shared kit (@yeetful/agent-kit)

An agent is a thin adapter; the kit provides:

• loadAgentWallet() — a viem WalletClient on Base from PRIVATE_KEY, or a throwaway key when none is set (so the default run is free and safe).
• createExpenseAccount({ allow, perCallUsd, perDayUsd, ... }) — the yeetful() grant-aware paid fetch, pre-wired with env (YEETFUL_API_KEY, YEETFUL_GRANT_ID, YEETFUL_LEDGER_URL) and a receipt log you can read back.
• isLive() — the single LIVE=1 gate every agent reads before it spends real USDC or places a real order.

The first agent (agents/coinbase)

A Coinbase trading agent built on the Advanced Trade API:

• Shows the portfolio — account balances + USD value.
• Places trades in order books — limit/market orders against a product's live best bid/ask.
• Pays x402 for its edge — before trading it buys a market signal through the expense account (allowlist-gated, receipted), demonstrating the payer side of Yeetful end-to-end.

Safe by default. With no keys it runs in dry-run: it previews orders and shows a sample portfolio, and spends nothing. Real reads/orders require LIVE=1 + real CDP keys. See agents/coinbase/README.md.

Adding an agent (one repo → many Vercel projects)

Same model as x402-services: a Vercel Project points at a folder inside this repo. Set Root Directory to agents/<name>; Vercel installs the whole workspace (so @yeetful/agent-kit resolves) and builds just that app. Each agent gets its own env vars and domain. Turborepo skips rebuilding unchanged projects.

Local dev

pnpm install
pnpm --filter coinbase-agent dev      # or: cd agents/coinbase && pnpm dev
pnpm typecheck                         # whole workspace
pnpm --filter coinbase-agent test      # JWT + order-builder unit tests

Copy agents/<name>/.env.example → .env and fill it in. .env is gitignored — never commit real keys.