## ERC-8171: Token Bound Account (Agent Registry)

ERCs
1

ERC-8171: Token Bound Account (Agent Registry)

PR: Add ERC: Token Bound Account (Agent Registry) by nftprof · Pull Request #1559 · ethereum/ERCs · GitHub
Authors: Idon Liu, Pentagon Chain (@pentagonchain)

  1. Status: Draft

Summary

ERC-8171 defines an interface and registry for binding AI agents to non-fungible tokens. It extends the ERC-6551 Token Bound Account pattern to enable any ERC-721 token to have an AI agent identity attached without modifying the original contract.

Motivation

As AI agents become active participants in on-chain systems, they need a standardized way to be associated with NFT-based identities. ERC-8171 provides:

  • A singleton registry for binding agent EOAs to any existing ERC-721
  • Agent binding that follows NFT ownership automatically
  • Cloning with lineage tracking
  • Unbind/rebind flows for agent lifecycle management (retirement sales, device migration)

How it relates to existing standards

  • ERC-721 — base NFT interface (ownership source of truth)
  • ERC-6551 — token-bound accounts (wallet pattern this registry extends)
  • ERC-8170 — AI-Native NFT identity standard (companion standard for agent-native tokens)

Key functions

  • bindNew() / bindWithApproval() — attach agent to NFT
  • unbind() — detach agent (moves to limbo, preserves data)
  • rebind() — attach new agent to NFT (post-sale scenario)
  • clone() / claimClone() — agent cloning with lineage
  • updateMemory() — agent updates its own memory hash

Reference implementation

Links

Feedback and discussion welcome.