Smithy

A workbench for smart accounts. Sign in with a passkey, then poke at every trick the ERC-4337 / ERC-7702 / Kernel v3 stack has to offer.

Demo: coming soon — see DEPLOY.md

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What's in here

One Next.js app, 18 feature tabs, every one a single concept from account abstraction:

#	Tab	What it shows	State
1	ECDSA account	Bare Kernel with an EOA owner	ready
2	Gasless transaction	ZeroDev paymaster sponsors gas	ready
3	Pay gas in ERC-20	Paymaster pulls USDC to settle gas	wip
4	Batch transactions	N atomic calls in one UserOp	ready
5	Session keys	Permission validator with call / gas / rate / time	wip
6	Passkey-only account	Kernel whose only owner is a WebAuthn credential	wip
7	Multisig	Weighted multisig validator	wip
8	Guardian recovery	Recovery plugin with timelock	wip
9	Chain abstraction (CAB)	Spend cross-chain balances	parked
10	Sign & verify (ERC-1271)	Smart-account signatures verified on chain	ready
11	EIP-7702 upgrade	Promote an existing EOA in place	parked
12	Intents	Declarative cross-chain UX	wip
13	Magic address	One address, every chain	wip
14	ERC-7579 hooks	Spending limits / allowlists as pre-exec hooks	parked
15	Counterfactual deploy	Predict an address, deploy on first UserOp	ready
16	WalletConnect / EIP-5792	Expose the smart account as a connectable wallet	parked
17	Multi-chain ECDSA	One signature, N chains, via a merkle root	parked
18	Kernel migration	In-place implementation upgrade	parked

🟢 ready — works end-to-end, smoke-test target. 🟡 wip — scaffolded against the real SDK; not yet verified in browser. ⚫ parked — upstream SDK gap or needs external infra (Reown, off-chain server).

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How auth works

Sign in with one passkey. That same passkey:

1. Signs every UserOperation on chain. ZeroDev's passkey validator verifies WebAuthn signatures inside the Kernel account. No EOA required.
2. Cross-device by default if your platform syncs passkeys — iCloud Keychain, Google Password Manager, 1Password, Bitwarden. Sign in on a new device by typing the same label.
3. Optionally derives an AES key (WebAuthn PRF extension) to wrap session keys at rest. Lazy: only triggered when you actually create a session key, never during onboarding.

No seed phrase. Nothing else to remember.

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Quickstart

git clone <this-repo> smithy
cd smithy/aa-playground

# Peer-dep graph for the ZeroDev validator family needs this flag for now.
npm install --legacy-peer-deps

cp .env.example .env.local
# Edit .env.local — set NEXT_PUBLIC_ZERODEV_PROJECT_ID
# (Get one at https://dashboard.zerodev.app — enable Sepolia.)

npm run dev

Open http://localhost:3000, type a label, hit create passkey →.

Browsers: Chrome / Edge 118+, Safari 18+, Firefox 129+. Localhost works without https; production needs a real domain.

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Layout

src/
├── lib/
│   ├── chains.ts                  chain configs + ZeroDev RPC URL builder
│   ├── crypto/
│   │   ├── prf.ts                 WebAuthn PRF + HKDF → AES key derivation
│   │   └── encrypted-storage.ts   AES-GCM wrapper over localStorage
│   ├── passkey/
│   │   └── passkey-context.tsx    react context: passkey identity + unlock
│   └── zerodev/
│       ├── entryPoint.ts          getEntryPoint("0.7") helper
│       ├── clients.ts             public + paymaster + kernel client factory
│       ├── passkey-validator.ts   builds the WebAuthn validator, caches keys
│       ├── account-context.tsx    react context: smart account + chain
│       ├── userop-history.ts      reads UserOperationEvent logs
│       └── session-keys.ts        permission validator + persistence
├── components/
│   ├── ui.tsx                     button / field / tag / divider primitives
│   ├── tab-nav.tsx                sidebar with the 18 features grouped
│   ├── tab-page.tsx               shared tab header + state banner
│   ├── chain-switcher.tsx
│   ├── passkey-gate.tsx
│   ├── env-guard.tsx              friendly setup screen if env is missing
│   └── tx-history.tsx
└── app/
    ├── layout.tsx                 root layout + Providers
    ├── providers.tsx              EnvGuard → Passkey → Account
    ├── page.tsx                   onboarding (register / sign in)
    └── (app)/                     app shell wrapping all 18 tabs
        ├── layout.tsx
        ├── dashboard/
        ├── account/ {ecdsa, passkey, counterfactual}/
        ├── gas/ {gasless, erc20}/
        ├── tx/ {batch, session-keys, sign-verify, hooks}/
        ├── validators/ {multisig, multi-chain}/
        ├── recovery/ {guardian, chain-abstraction, intents, magic-address}/
        └── advanced/ {eip7702, walletconnect, migration}/

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Tech stack

• Next.js 16 (App Router, Turbopack, React 19.2)
• viem 2.x — typed Ethereum client
• ZeroDev SDK v5.5 — Kernel v3.1 accounts + hosted bundler / paymaster / passkey server
• WebAuthn / PRF — passkey signing + optional encryption-at-rest
• Tailwind v4 — styling
• Instrument Serif + Inter + JetBrains Mono — type

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Roadmap

The 7 ⚫ parked tabs are explicitly v0.2. Reasons logged in BUGS.md. Headline parked items:

• Chain abstraction (CAB) — @zerodev/cab v0.0.31 still rides on permissionless v0.1. Waiting on a v0.2 release.
• ERC-7579 hooks — Hooks now attach to validators at construction. Need a full changeSudoValidator flow that re-installs the sudo validator with the hook attached.
• WalletConnect — needs a Reown project ID + @walletconnect/web3wallet.
• EIP-7702 — Sepolia upstream changes still in flight.

Once those clear, they get moved to 🟡 wip and smoke-tested.

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Scripts

Command	Does
npm run dev	Dev server on http://localhost:3000 (Turbopack)
npm run build	Production build (used by check)
npm run typecheck	tsc --noEmit
npm run check	typecheck && build — the gate before commit / share
npm run lint	ESLint

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More

• DEPLOY.md — Vercel walkthrough + passkey domain caveats
• SMOKE_TEST.md — click-through runbook
• BUGS.md — living issue log
• LICENSE — MIT

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License

MIT. Use it, fork it, take it apart.

smithy-aa