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The guard

A guard that can only bring your money home.

You deposit into a vault through a small contract you own. When NOCK raises a run or contagion on that vault, NOCK's keeper calls one function, exit(). It withdraws everything the vault will release and sends it to you. If the market is short of cash, it takes what is there and comes back for the rest.

01Limits

The keeper cannot

  • send your money anywhere but back to you
  • deposit, withdraw to itself, or move part of it somewhere else
  • change the vault your deposit sits in
  • make itself keeper again once you revoke it

02Your controls

You can, at any time

  • withdraw any amount to yourself
  • call exit() yourself
  • revoke the keeper, or name a different one

Each of these is proven by the contract's test suite, including a vault that tries to re-enter the guard and a randomised test that no value is ever lost.

03Where it runs

Testnet and mainnet

Guards run on Arc: on testnet with test dollars anyone can mint, and on mainnet over the Steakhouse Prime USDC vault NOCK watches. The contract has not been audited; mainnet deposits are capped per guard.

What the guard cannot beat: a direct drain. Drift lost $285M in about 12 minutes on 1 April 2026; no watcher is that fast. The guard is for the second wave, when an exploit or a run spreads to the markets you are in. Guards run on EVM networks; Solana positions are watched and alerted, not guarded.

Try it

Sign in, open Guard, and create one on Arc Testnet with free test dollars. Your testnet guard follows the live alarms for Arc's Steakhouse Prime USDC vault, and you can ask the keeper for a drill and watch it pull your deposit out. On Arc mainnet the same guard holds real USDC, and you can run one real drill a day.

Open your guard