You're pledging to donate if the project hits its minimum goal and gets approved. If not, your funds will be returned.
$15,000 left to reach the funding goal.
AI agents are beginning to be able to hold money and make payments themselves. They also consume large amounts of often untrusted text, which is sometimes written by people trying to persuade the agent to take certain actions. In May 2026, someone sent a message in Morse code which resulted in $150–200k being paid out from an agent’s wallet in Grok. There is currently no solution to this problem once the payment is made on the blockchain it is gone in seconds. Brake buys you time to cancel a payment. Payments to trusted addresses, under a daily limit, are accepted immediately. All other payments are paused publicly for an hour, during which anyone with a brake key can cancel them for another 6 hours or permanently. You specify who receives a brake key: your phone, a friend, or a watcher bot. The key takeaway here is that a brake key can cancel payments, but never make them. Therefore, giving one to a bot or a friend can’t risk your money. The agent making the payment can’t modify the rules either. Cancelling any payment simply requires removing its brake key: everything it had scheduled for the next 6 hours is cancelled.
It works today on two testnets: Walkthrough,
no wallet required: https://brake-simulation.vercel.app
Sui Testnet demo: https://trybrake.vercel.app (code: https://github.com/zayn-kahn/trybrake)
Base Sepolia demo: https://usebrake.vercel.app (code: https://github.com/zayn-kahn/usebrake)
I want this project to be boring and pragmatic: the agent is allowed to perform actions, but a human can always stop it. That should be true for agent wallets before they hold real money. The next steps towards this goal are:
Owner delay. Currently, if the owner takes an action, it is performed immediately. I will implement an optional owner delay just like the user delay, so that even a stolen owner key gives you time to stop it.
A real watcher. A small open-source watcher bot which can watch the queue, alert you on your phone, and pause questionable payments.
Agent support. A basic SDK and one plugin for an agent framework, to allow the agent to check its limits and ask permission before attempting an action.
Review. More testing, specification, and an external security audit before anyone trusts this with real money.
This money will fund my time to work on the four items above, and partially fund a security audit. If I raise the minimum, I will implement the owner delay, and the watcher bot. If I raise the maximum, I will work on all four items.
I'm Muhammad Zain Khan, a smart contract engineer with 4 years of production Solidity under my belt, and 20 hours per week on Brake. I have designed and deployed multi-signature wallet contracts with on-chain authentication. I've also written a Move migration which moved 2,700+ NFTs from Ethereum to Aptos, authorised by on-chain signatures. Brake began as an outgrowth of my AI safety research: in a pre-registered experiment, Vault Village, LLM agents are given a 3-of-4 Solidity multisig with a co-owner who steals from it, and the experiment measures whether they report the thief: https://github.com/zayn-kahn/ai-safety-experiment. Both Brake builds are open-source: an ERC-7579 module on Base Sepolia, and a Move package on Sui testnet.
Lack of adoption. Organisations may prefer to enforce spending limits, rather than introducing a delay. In this case, the code and concept will still be open-sourced, allowing others to adopt it. The owner key remains a weak link: If people come to regard the owner delay as an inconvenience and disable it, then a stolen owner key can drain the wallet. A bug. Since this code has not been audited, users should not trust it with real money until it has been.
None. I am also seeking funding from the Sui Foundation, and will apply to the Ethereum Foundation later.