erc-8259

Standard Solidity interfaces and ERC8259Guard for ERC-8259: AI Agent Identity & Threat Registry.

Protect your DeFi protocols and smart contracts from rogue autonomous AI agents in 2 lines of code.

[!CAUTION] CRITICAL SECURITY FIX - v1.3.0 - UPGRADE IMMEDIATELY Versions prior to 1.3.0 contained a logic flaw where deactivated agents retained verified status:

• getEffectiveTier(agent) returned non-zero for deactivated agents with unexpired tiers.
• isVerified(agent) returned true for deactivated agents.
• calculateTrustScore(agent) awarded full trust score to deactivated agents. This allowed banned/compromised agents to bypass ERC8259Guard checks. Found by internal audit (2026-11-04) - present since v1.0.0. Upgrade to v1.3.0 immediately. See CHANGELOG.md for details.

[!IMPORTANT] UPGRADE NOTICE FOR USERS OF v1.0.x / v1.1.0: Versions prior to 1.2.0 contained a desynchronized version of IAgentIdentityRegistry.sol:

• Missing uint256 verificationExpiry in AgentIdentity.
• Missing getEffectiveTier(address).
• Incorrectly accepted verificationTier in registerAgent(), which allowed self-assigned verification tiers.

Upgrade to v1.2.1 immediately. In v1.2.0+, newly registered agents strictly initialize at Tier 0 (unverified), and verification status expires dynamically via getEffectiveTier(). See CHANGELOG.md for details.

📦 Installation

npm install erc-8259

Or with yarn / pnpm:

yarn add erc-8259
pnpm add erc-8259

With Foundry:

forge install sigui-protocol/contracts

🛡️ Quickstart: 2-Line Integration

Inherit ERC8259Guard and append onlySafeAgent to any function you want to protect against known rogue agents or exploit bots:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

// 1. Import
import {ERC8259Guard} from "erc-8259/contracts/ERC8259Guard.sol";

// 2. Protect sensitive logic
contract Vault is ERC8259Guard {
    constructor(address _threatRegistry) 
        ERC8259Guard(_threatRegistry, address(0)) {}

    function withdrawLiquidity(uint256 amount) external onlySafeAgent {
        // Attackers flagged in the decentralized registry are reverted instantly.
    }
}

🔍 Available Modifiers

| Modifier | Description | |---|---| | onlySafeAgent | Reverts if the caller (msg.sender) is marked as an attacker in IThreatRegistry. | | onlyVerifiedAgent | Requires the agent to be safe AND registered with a verification tier (Tier > 0). | | minTrustScore(threshold) | Enforces a minimum trust score (0 to 1000 basis points, e.g. 700 = 70.0%). |

📍 Live Deployments

[!WARNING] ⚠️ DEPRECATED CONTRACT NOTICE (Sepolia): The Vyper contract deployed at 0x3806aeb76eDD2E22D3cF66A163113c4b24243b29 predates ERC-8259 PR #2137 and does NOT include verification_expiry, get_effective_tier, or incident lifecycle (retract_attack/resolve_attack). It accepts verification_tier directly at registration (privilege escalation risk). DO NOT use this address in production or as a reference implementation. A corrected deployment is tracked at Redeployment Issue #2.

| Network | Contract | Status | Address | |---|---|---|---| | Ethereum Sepolia | AgentIdentityRegistry | ⚠️ DEPRECATED (Pre-PR #2137) | 0x3806aeb76eDD2E22D3cF66A163113c4b24243b29 | | Aptos Testnet | agent_reputation | ⏳ Not deployed — source only | — (deployment planned; full tx hash will be published upon deployment) |

📜 Standard Specification

• Specification: ERC-8259 Spec
• Discussion Forum: Fellowship of Ethereum Magicians
• Changelog: Full history in CHANGELOG.md
• License: CC0-1.0