FactValidityProxy

A proxy contract that validates Cairo facts by calling isCairoFactValid on a target validator contract. The contract includes an owner-controlled mechanism to update the target validator address.

Contract Overview

FactValidityProxy.sol

The main proxy contract with the following features:

• Owner-controlled: Only the owner can update the target contract address
• Public validation: Anyone can call isValid to check fact validity
• Ownership transfer: Owner can transfer ownership to another address

Functions

Function	Access	Description
isValid(bytes32 fact)	Public	Check if a fact is valid (calls target with is_mocked=true)
isValidWithMock(bytes32 fact, bool is_mocked)	Public	Check fact validity with custom is_mocked parameter
setTargetContract(address)	Owner only	Update the target validator contract address
transferOwnership(address)	Owner only	Transfer contract ownership
getTargetContract()	Public	Get current target contract address
owner()	Public	Get current owner address
targetContract()	Public	Get current target contract address

Events

• OwnershipTransferred(address indexed previousOwner, address indexed newOwner)
• TargetContractUpdated(address indexed previousTarget, address indexed newTarget)

Setup

Prerequisites

• Foundry

Install Dependencies

forge install

Deployment

Environment Variables

Set the following environment variables:

export RPC_URL="<your_rpc_url>"
export PRIVATE_KEY="<your_private_key>"
export TARGET_CONTRACT="<target_validator_address>"

Deploy Contract

forge script script/FactValidityProxy.s.sol:FactValidityProxyScript \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast

Important: After deployment, update deployments.json with your deployment details.

Deploy with Etherscan Verification

forge script script/FactValidityProxy.s.sol:FactValidityProxyScript \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast \
  --verify \
  --etherscan-api-key $ETHERSCAN_API_KEY

Verify Existing Contract

forge verify-contract <DEPLOYED_ADDRESS> \
  src/FactValidityProxy.sol:FactValidityProxy \
  --chain sepolia \
  --constructor-args $(cast abi-encode "constructor(address)" $TARGET_CONTRACT) \
  --etherscan-api-key $ETHERSCAN_API_KEY

Scripts

1. Deploy (script/FactValidityProxy.s.sol)

Deploys the FactValidityProxy contract.

forge script script/FactValidityProxy.s.sol:FactValidityProxyScript \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast

2. Check Fact Validity (script/CheckFactValidity.s.sol)

Checks if a fact hash is valid (read-only, no gas required).

PROXY_ADDRESS=<deployed_proxy_address> \
FACT_HASH=<bytes32_fact_hash> \
forge script script/CheckFactValidity.s.sol:CheckFactValidityScript \
  --rpc-url $RPC_URL

3. Set Target Contract (script/SetTargetContract.s.sol)

Updates the target validator contract address (owner only).

PROXY_ADDRESS=<deployed_proxy_address> \
NEW_TARGET=<new_target_address> \
forge script script/SetTargetContract.s.sol:SetTargetContractScript \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast

4. Full Test (script/TestFactValidityProxy.s.sol)

Tests multiple contract functions including isValid and optionally setTargetContract.

# Test isValid only (read-only)
PROXY_ADDRESS=<deployed_proxy_address> \
forge script script/TestFactValidityProxy.s.sol:TestFactValidityProxyScript \
  --rpc-url $RPC_URL

# Test isValid + setTargetContract
PROXY_ADDRESS=<deployed_proxy_address> \
NEW_TARGET=<new_target_address> \
forge script script/TestFactValidityProxy.s.sol:TestFactValidityProxyScript \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast

Deployment Tracking

All deployments must be recorded in deployments.json. After each deployment, add an entry:

{
  "date": "YYYY-MM-DD",
  "network": "sepolia",
  "proxyAddress": "0x...",
  "targetAddress": "0x...",
  "ownerAddress": "0x...",
  "deployer": "@github_username"
}

Project Structure

verifier-proxy/
├── src/
│   └── FactValidityProxy.sol       # Main proxy contract
├── script/
│   ├── FactValidityProxy.s.sol     # Deploy script
│   ├── CheckFactValidity.s.sol     # Check fact validity script
│   ├── SetTargetContract.s.sol     # Set target contract script
│   └── TestFactValidityProxy.s.sol # Full test script
├── lib/
│   └── forge-std/                  # Foundry standard library
├── deployments.json                # Deployment tracker
├── foundry.toml                    # Foundry configuration
└── README.md

License

MIT