FolioVersionRegistry Contract

Tracks Folio implementation versions and manages version deprecation

Overview

The FolioVersionRegistry contract maintains a registry of Folio implementation versions. It tracks which deployer contracts are available for creating new Folios and allows the protocol to deprecate insecure or outdated versions.

Key Features

• Version Tracking: Maps version strings to FolioDeployer contracts
• Latest Version: Maintains pointer to most recent deployment
• Deprecation: Can mark versions as deprecated for security
• Version Queries: Retrieve deployer and implementation for any version

Registration Functions

Register Version

Register a new Folio version with its deployer.

folioDeployer · IFolioDeployer

Address of the FolioDeployer contract for this version

FolioVersionRegistry.sol

function registerVersion(IFolioDeployer folioDeployer) external

The version string is automatically read from the deployer contract using Versioned(address(folioDeployer)).version(). Each version can only be registered once.

Only protocol owners can register new versions. The newly registered version automatically becomes the latest version.

Deprecate Version

Mark a version as deprecated, preventing its use in UI and warning users.

versionHash · bytes32

Keccak256 hash of the version string to deprecate

FolioVersionRegistry.sol

function deprecateVersion(bytes32 versionHash) external

Deprecation is irreversible. This should only be used for versions with security issues or critical bugs. Requires owner or emergency council role.

Query Functions

Get Latest Version

Retrieve the most recently registered version.

FolioVersionRegistry.sol

function getLatestVersion() external view returns (
    bytes32 versionHash,
    string memory version,
    IFolioDeployer folioDeployer,
    bool deprecated
)

Returns:

• versionHash: Keccak256 hash of version string
• version: Human-readable version string (e.g., “3.4.1”)
• folioDeployer: Deployer contract address
• deprecated: Whether this version is deprecated

The latest version may be deprecated if it was the most recent registration before being flagged. Always check the deprecated flag.

Get Implementation for Version

Retrieve the Folio implementation address for a specific version.

versionHash · bytes32

Version hash to look up

FolioVersionRegistry.sol

function getImplementationForVersion(
    bytes32 versionHash
) external view returns (address folio)

Get Deployer

Direct mapping access to get deployer for a version hash.

FolioVersionRegistry.sol

function deployments(bytes32 versionHash) external view returns (IFolioDeployer)

Check Deprecation Status

Check if a version is deprecated.

FolioVersionRegistry.sol

function isDeprecated(bytes32 versionHash) external view returns (bool)

Events

VersionRegistered · event

Emitted when a new version is registered

Parameters:

• versionHash - Keccak256 hash of version string
• folioDeployer - Deployer contract address

VersionDeprecated · event

Emitted when a version is deprecated

Parameters:

• versionHash - Hash of deprecated version

Errors

VersionRegistry__ZeroAddress · error

Thrown when trying to register a zero address

VersionRegistry__InvalidCaller · error

Thrown when caller lacks required permissions

VersionRegistry__InvalidRegistration · error

Thrown when trying to register an already-registered version

VersionRegistry__AlreadyDeprecated · error

Thrown when trying to deprecate an already-deprecated version

VersionRegistry__Unconfigured · error

Thrown when querying an unregistered version

Access Control

roleRegistry · IRoleRegistry

Immutable reference to the RoleRegistry for permission checks

Permissions:

• registerVersion(): Requires owner role
• deprecateVersion(): Requires owner or emergency council role

Version Hash Calculation

Version hashes are calculated as:

bytes32 versionHash = keccak256(abi.encodePacked(version));

For example, version “3.4.1” becomes:

keccak256(abi.encodePacked("3.4.1"))

Usage Example

// Register a new version
FolioDeployer deployer = new FolioDeployer(/* ... */);
versionRegistry.registerVersion(deployer);

// Query latest version
(
    bytes32 versionHash,
    string memory version,
    IFolioDeployer folioDeployer,
    bool deprecated
) = versionRegistry.getLatestVersion();

require(!deprecated, "Latest version is deprecated");

// Use the deployer to create a Folio
address newFolio = folioDeployer.deployFolio(/* ... */);

// If security issue found
versionRegistry.deprecateVersion(versionHash);

Integration with Versioned Contract

All FolioDeployer contracts must inherit from the Versioned base contract, which implements a version() function returning a semantic version string.

contract FolioDeployer is Versioned {
    // version() returns something like "3.4.1"
}

Frontend Integration

Frontends should always check both if a version exists and whether it’s deprecated before allowing users to deploy with it. Use getLatestVersion() to show the recommended version.