Tappy

AI agent wallet that uses a NFC tag / flipper zero to verify transactions

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Tappy

An AI agent wallet the agent can't drain. The agent holds one key, and you hold the other on a Flipper Zero. Every transaction is 2-of-2: the agent can propose anything, and nothing moves until a human physically presses the button.

Built for ETHOnline 2026

Agent wallets with spending limits already exist. A policy file is not a person. Tappy's second factor is a thumb.

How it works

you → chat → the agent proposes → agent signs → Flipper shows it → you press OK
                                                                       ↓
                                             human signs → TappyGate.execute() → chain

TappyGate is a ~70-line contract that verifies both signatures over one EIP-712 digest. Neither key can move funds alone.

Repo layout

Path What it is
apps/hub API only: agent loop, proposal store, relayer, the iOS and bridge surfaces (T3 stack)
apps/bridge Node process on the laptop: talks to the Flipper over USB, holds the human key (v1)
apps/mobile React Native client — placeholder, not started
packages/protocol Shared types, EIP-712 digest, the mock signer, the frozen test vector
packages/contracts Foundry: TappyGate, MockToken, MockSwap, MockMerchant
device/tappy-js The Flipper app (JavaScript)
device/tappy-c On-device signing — stretch goal, not started
docs/ SPEC.md, per-person briefs, spike log
site/ The public page, deployed to GitHub Pages — it recomputes the digest in the browser

Quick start

./scripts/setup.sh      # installs pnpm + Foundry, creates .env files, runs the tests

Or by hand:

nvm use                 # Node 22
pnpm install
pnpm contracts:test     # 13 tests, includes the cross-language digest vector
pnpm --filter @tappy/protocol test

Foundry is required for the contracts:

curl -L https://foundry.paradigm.xyz | bash && foundryup

foundryup prints the bin directory to add to your shell profile. It is ~/.foundry/bin on most machines, but ~/.config/.foundry/bin if XDG_CONFIG_HOME is set — ./scripts/setup.sh finds it either way.

OpenZeppelin comes from pnpm (foundry.toml remaps it into node_modules), so run pnpm install before forge test.

You do not need a Flipper Zero to work on this. MockHumanSigner satisfies the same interface as the real device and can auto-approve, auto-reject, or ask you y/n in the terminal. Two thirds of the project is built against it.

Who's doing what

Workstream Owner Start here
A contracts, protocol, deploys @IGanjali brief · issue #4
B iOS app, hub, agent loop @ryannzander brief · issue #2
C Flipper + bridge @AnshuPlayz17 brief · issue #1

Three issues are labelled blocker and should be picked up in hour one. Everything else is labelled by milestone on the issue board.

Where to start reading

  1. docs/HANDOFF.md — if you're picking this up on a new machine, start here.
  2. docs/SPEC.md — architecture, contract design, milestones, cut lines, demo script.
  3. Your brief: contracts · app · device
  4. CONTRIBUTING.md — branches, PRs, and the rules that keep three people out of each other's way.

Status

Milestone State
M0 scaffold, protocol, contracts, mock signer done
M1 gate deployed on Sepolia not started
M2 chat → agent → proposal → tx not started
M3 Flipper in the loop not started
M4 shop, swap, the attack scene not started
M5 Arc + Hedera + Privy not started
M6 on-device signing (stretch) not started

Honest limitations

  • v1 keeps the human key on the laptop. The Flipper is the approval factor, not yet the custodian. On-device secp256k1 is verified feasible (~0.1–0.3 s per signature) and specced in device/tappy-c/README.md, but it needs a C app. See SPEC §1.
  • The device shows a summary the laptop sends. "What you see is what you sign" is v2.
  • A connected laptop can inject button presses through the Flipper's CLI. In v1 the laptop holds the key anyway, so this changes nothing; the C version disables the CLI while running.

Testnet only. Do not put real funds anywhere near this.

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