Certify

On-chain certification of content hashes using Ethereum. Prove that content existed at a specific point in time.

Deployed Contracts

Network	Address	Explorer
Mainnet	0x4f2a70eC878E9Adae88FF0c7528ebEbf83dFD83c	Etherscan
Sepolia	0x125721f8a45bbABC60aDbaaF102a94d9cae59238	Etherscan

Quick Start

Prerequisites

• Foundry
• uv
• Wallet with ETH (testnet or mainnet)

Setup

git clone <repo-url> && cd certify
forge install
uv sync
cp .env.example .env  # Edit with your keys

Certify Content

# Edit certify.conf with your URL/file
uv run python3 -m certify_cli certify --network sepolia

Verify a Certification

uv run python3 -m certify_cli verify

CLI Commands

# Deploy contract
uv run python3 -m certify_cli deploy --network mainnet

# Certify (EOA)
uv run python3 -m certify_cli certify --network mainnet

# Certify via Gnosis Safe
uv run python3 -m certify_cli certify --network mainnet --safe 0x... --execute

# Verify
uv run python3 -m certify_cli verify --rpc-url https://... --contract 0x...

Configuration

.env — Secrets (private keys, RPC URLs)

MAINNET_RPC_URL="https://ethereum-rpc.publicnode.com"
MAINNET_PRIVATE_KEY="0x..."
SEPOLIA_RPC_URL="https://ethereum-sepolia-rpc.publicnode.com"
SEPOLIA_PRIVATE_KEY="0x..."
CERTIFY_ADDRESS="0x..."

certify.conf — What to certify

CERTIFY_SOURCE="https://example.com"
CERTIFY_DESCRIPTION="My certification"

Documentation

Topic	Document
Trust model & address roles	doc/trust_model.md
Mainnet deployment guide	doc/mainnet_deployment.md
Gnosis Safe integration	doc/safe_integration.md

Contract API

// Certify content
certifyWebsite(string url, bytes32 contentHash, string description)

// Query
hashUrl(string url) → bytes32
hashContent(bytes content) → bytes32

Events: Certified, WebsiteCertified, VerificationProgressCertified

Development

forge build      # Build contracts
forge test -vvv  # Run tests
uv run ruff check certify_cli/  # Lint Python

License

MIT