LEASH

Put your agent on a leash.

Onchain spend allowances for AI agents and automations on Monad testnet — fund a personal vault, attach hard caps, revoke instantly, and audit every action through a live ledger.

Tagline

Programmable onchain allowances so agents can spend for you without spending you.

Problem

Agents need wallets to act, but unlimited approvals and hot keys are a personal disaster.

• You want an agent to pay, trade, or hit APIs.
• You do not want infinite approve, shared private keys, or “trust me” offchain limits.
• When something goes wrong, you need a hard stop and a verifiable trail — not a spreadsheet and a hope.

This is a problem I hit the moment agent + money touch the same wallet.

Solution

LEASH is a personal policy vault for agent spend:

1. You create a vault and deposit USDC (owner-controlled custody).
2. You open a session for a spender (agent wallet): total cap, optional period cap, expiry, optional allowlist, optional ERC-8004 agentId.
3. The agent can only spend inside that policy; over-cap / bad recipient / expired → reverts onchain.
4. You can revoke in one transaction.
5. Everyone can read the story on the Envio activity ledger (not a mocked feed).

Hard limits live in Solidity. The UI is a command center, not the source of truth.

Architecture

Layer	Name	What it does
①	SURFACE	Next.js command center — wallet UX, fund, sessions, ledger, spend simulator
②	ACCESS	Wallet writes · thin Express/viem API · Envio GraphQL reads
③	CUSTODY	LeashFactory + LeashVault — one vault per owner, deposit/withdraw
④	LEASH	Sessions: caps, period, expiry, allowlist, canSpend, spend, revoke
⑤	PROOF	Envio HyperIndex → live Activity feed · explorers for tx proof

Agent spend loop: preflight (canSpend) → onchain spend → events indexed → ledger updates.

Features

Feature	Description
Personal vault	One vault per owner via factory
Deposit / withdraw	Owner moves USDC in and out
Agent sessions	Cap, period cap, expiry, agentId, allowlist
Onchain enforcement	spend only by spender; caps are hard
Preflight	canSpend view + API + Policy lab UI
Spend simulator	Demo agent spend without a real bot
Instant revoke	Owner cuts the leash in one tx
Live ledger	Envio-indexed Vault / Session / Activity
Command-center UI	Dark operational design (not a generic template)

Demo

https://youtu.be/3S0eR4LAb9M

Tech Stack

Layer	Stack
Chain	Monad testnet (10143)
Contracts	Solidity 0.8 · Foundry · OpenZeppelin
Indexer	Envio HyperIndex (hosted GraphQL)
API	Node · Express · viem
Frontend	Next.js 15 · TypeScript · Tailwind CSS
Wallet	Wagmi · viem · RainbowKit
Data / state	TanStack Query · Axios · Zustand
Motion	Framer Motion (landing atmosphere)

Smart Contracts

There is no separate “ToolRegistry.” The onchain surface is a factory + personal vault.

Contract	Role
LeashFactory	createVault / createVaultFor · vaultOf(owner) · one vault per owner
LeashVault	deposit · withdraw · createSession · spend · revoke · canSpend · allowlist

Address

Network	Contract	Address
Monad testnet	LeashFactory	0x5BA28C60b1A49C809c9A455cca1436bff86a49e0
Monad testnet	USDC (x402 guide)	0x534b2f3A21130d7a60830c2Df862319e593943A3

Vaults are created per user by the factory (clone / deploy pattern via createVault). Look up yours with vaultOf(owner) or the app overview after connecting.

Explorer

• Factory (MonadVision): https://testnet.monadvision.com/address/0x5BA28C60b1A49C809c9A455cca1436bff86a49e0
• Factory (MonadScan): https://testnet.monadscan.com/address/0x5BA28C60b1A49C809c9A455cca1436bff86a49e0

Indexer (GraphQL)

https://indexer.dev.hyperindex.xyz/25cb989/v1/graphql

Example:

{
  _meta { isReady progressBlock eventsProcessed }
  Vault(limit: 5) { address owner depositCount sessionCount }
  Activity(order_by: { timestamp: desc }, limit: 10) { kind txHash amount }
}

Repository Structure

LEASH/
├── architecture.svg          # System architecture diagram
├── README.md
├── backend/                  # Contracts + thin API
│   ├── src/                  # LeashFactory, LeashVault, mocks
│   ├── test/                 # Foundry tests (10/10)
│   ├── script/               # Deploy scripts
│   ├── abi/                  # Exported ABIs
│   ├── deployments/          # chainId → addresses (e.g. 10143.json)
│   └── api/                  # Express + viem read/preflight API
├── indexer/                  # Envio HyperIndex project
│   ├── config.yaml
│   ├── schema.graphql
│   └── src/handlers/         # Vault + factory event handlers
└── frontend/                 # Next.js command center
    ├── DESIGN.md             # UI design system
    └── src/
        ├── app/              # Routes: /, /app, fund, sessions, ledger, policy-lab
        ├── components/       # UI + LEASH domain + motion
        ├── hooks/            # vault / sessions / ledger
        └── lib/              # wagmi, envio, api, abis

Quick Start

Prerequisites

• Node.js 22+
• Foundry (forge, cast)
• Monad testnet MON (gas) + testnet USDC for deposits
• WalletConnect project id (optional for WalletConnect; injected wallets work)

1. Contracts (optional local verify)

cd backend
forge test -vv

Deploy (see backend/script/deploy.sh + backend/.env.example).
Already deployed factory address is in backend/deployments/10143.json.

2. API (policy preflight)

cd backend/api
cp ../.env.example .env   # set LEASH_FACTORY_ADDRESS, RPC_URL, etc.
npm install
npm run dev               # default http://localhost:8787

3. Indexer

Hosted indexer is already running (URL above). For local Envio:

cd indexer
pnpm install
pnpm codegen
# see indexer/README.md for dev / cloud deploy

4. Frontend

cd frontend
cp .env.example .env.local
# set NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID if needed
# GraphQL + factory defaults match testnet deploy
npm install
npm run dev               # http://localhost:3000

Env (frontend)	Purpose
NEXT_PUBLIC_LEASH_FACTORY	Factory address
NEXT_PUBLIC_USDC	Testnet USDC
NEXT_PUBLIC_ENVIO_GRAPHQL_URL	Envio GraphQL endpoint
NEXT_PUBLIC_API_URL	Backend API (policy lab)
NEXT_PUBLIC_RPC_URL	Monad RPC
NEXT_PUBLIC_CHAIN_ID	10143

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Security notes

• Owner controls deposit, withdraw, create session, revoke.
• Spender can only spend within an active session policy.
• Backend API is read / preflight only — it does not hold private keys.
• Never commit .env / .env.local (see root .gitignore).

License

Hackathon project (BuildAnything Spark · Monad). See individual package folders for dependency licenses.