MetaMask Snap · Ethereum mainnet

Proof inside the MetaMask confirmation.

Proof Before Sign is a MetaMask Snap. Before you confirm an Ethereum mainnet transaction, it shows who audited the contract and whether the live code is the audited build. No audit on record? It shows who can upgrade the contract.

Install the Snap See example panels

The MetaMask Snap is free.

MetaMaskConfirm transaction

Ethereum Mainnet · Contract interaction

Proof Before Sign

Illustration with example data. Panel text comes from the Snap's own code.

The answer, in the confirmation window.

Proof Before Sign adds a panel to the MetaMask confirmation. It reads the exact transaction and shows what is known, what changed and what is missing.

Audited and matching

Who audited it, which report and commit, whether the live build matches, whether it was upgraded since, and open findings at release.

Shortened example. The real panel also shows call counts and the checked block.

No released audit

Review coverage · this exact transaction

UNKNOWN

Review coverage is not established for the assessed components.

No released audit · source verified (Sourcify), not audited · upgradeable ERC-1967 proxy

Source: verified on Sourcify · source verified ≠ audited
Proxy: ERC-1967 proxy · implementation 0x222222…222222
Can be upgraded by: 0x777777…777777 · Safe 2-of-3 · timelock 1 d

Request an audit listing →

Audited by: not established
Implementation matches audited build: unknown
Upgraded since audit: unknown
Open findings: not established

All details are from the signed, transaction-bound proof.

No audit on record? You still see the facts: source verification (which is not an audit), the proxy and its implementation, and who can upgrade it, with a link to request an audit listing.

Shortened example. The real panel also shows call counts and the checked block.

Risky approval

Review coverage · this exact transaction

UNKNOWN

Review coverage is not established for the assessed components.

No released audit · source verified (Sourcify), not audited · upgradeable ERC-1967 proxy

Unlimited approval: the spender can move all of this token

Spender is a wallet (EOA), not a contract

Spender 0x9999999999999999999999999999999999999999 · unsigned lookup

Source: verified on Sourcify · source verified ≠ audited
Proxy: ERC-1967 proxy · implementation 0x222222…222222
Can be upgraded by: 0x777777…777777 · Safe 2-of-3 · timelock 1 d

Request an audit listing →

Audited by: not established
Implementation matches audited build: unknown
Upgraded since audit: unknown
Open findings: not established

All details are from the signed, transaction-bound proof.

Unlimited approvals and approvals to a wallet instead of a contract get a red warning before you sign.

Shortened example. The real panel also shows call counts and the checked block.

Install status

Checking install status…

Once MetaMask approves a Snap, ordinary MetaMask can install it. Until then, MetaMask Flask, MetaMask's developer build, installs the published package. The install page shows the current status.

What it sends

Proof of Audits never asks for your recovery phrase or private key. When transaction checks are on, the proposed Ethereum mainnet transaction is sent to Proof of Audits for analysis. Nothing is sent while checks are paused.

Where the check stops

Checks Ethereum mainnet transactions only.
ERC-2612 Permit and Permit2 signatures get a contract status lookup. Logins and message signing get no panel.
Missing evidence stays unknown.

Proof of Audits does not guarantee safety.

Use another wallet? A browser extension for other wallets on Chrome and Brave is in testing.

See the browser extension