Persistent Identity Protocol

Persistent Identity Protocol (PIP) is a Web3 identity standard for creating persistent, human-readable identity objects mapped to EVM addresses.

It is designed for applications, games, communities, chains, and namespace operators that want to replace traditional usernames with programmable on-chain identities.

Core Idea

Web2 username systems are platform-controlled and disposable. Web3 addresses are owned, but not human-readable.

Persistent Identity Protocol bridges both models:

username → identity token → EVM address → on-chain records → programmable identity

Features

• Human-readable IDs mapped to EVM addresses
• Identity NFTs or SBTs — transferable when unbound, soulbound when bound
• Persistent username binding with governance-controlled unbinding
• Ownership and change history — all on-chain
• On-chain URL forwarding — canonical URL records per identity
• Configurable namespace policies — pricing, tiers, reserved names, moderation
• Economic spam resistance — configurable mint pricing prevents bot registration
• Login system compatible — identity name → wallet → existing account
• White-label namespace support — any app can launch its own identity namespace
• Metadata extensible — AI classification, rarity signals, social data

Architecture

The standard defines three interface layers:

Layer	Interface	Purpose
Identity	IPersistentIdentity	Name registration, address binding, URL records, soulbound locking
Resolution	IPersistentIdentityResolver	Convenience functions for name → address/URL/identity lookup
Policy	IPersistentIdentityPolicy	Governance: pricing, rename, unbind, purchase

┌──────────────────────────────────────────────────┐
│              Applications / Wallets               │
│   (login, social, games, agents, marketplaces)    │
├──────────────────────────────────────────────────┤
│           IPersistentIdentityResolver             │
│        resolveAddress · resolveUrl · resolveId    │
├──────────────────────────────────────────────────┤
│             IPersistentIdentity (ERC-721)          │
│   nameOf · bind · boundAddress · urlRecord · tier  │
├──────────────────────────────────────────────────┤
│            IPersistentIdentityPolicy              │
│      unbind · rename · setPrice · purchaseMint    │
├──────────────────────────────────────────────────┤
│                 EVM (any chain)                    │
└──────────────────────────────────────────────────┘

Identity Lifecycle

MINT (unbound, transferable)
  │
  ├─ User calls bind() → BOUND (soulbound, locked)
  │    ├─ Can set URL record
  │    ├─ Can use as login credential
  │    ├─ Name resolves to user's address
  │    └─ Cannot transfer
  │
  ├─ Policy calls unbind() → UNBOUND (transferable again)
  │    └─ URL record and binding cleared
  │
  └─ Transfer → New owner (unbound)
       └─ Binding and URL cleared automatically

Reference Implementation

PEG ID at id.peg.gg is the first reference implementation, deployed on Pentagon Chain (chain ID 3344).

• Contract: 0xf97EB9f8293D1FD5587a809Eb74518c300738d07
• 90+ identities minted
• AI-driven classification and pricing
• Pentagon.games login integration
• Metadata API with dynamic SVG identity cards

Comparison

Feature	Web2 Usernames	ENS	PIP
Ownership	Platform-controlled	User-owned (lease)	User-linked (persistent)
Expiry	Can be deleted	Must renew	No expiry by default
Transferability	No	Yes (tradable)	SBT when bound, tradable when unbound
Login Compatible	Native	Not designed for login	Designed for login
URL Forwarding	DNS-based	Partial (resolver)	On-chain URL record
Bot Resistance	Weak	Weak	Economic pricing + persistence
Namespace Control	Centralized	Global public	Configurable per namespace
Social Graph	Platform-specific	Limited	Cross-app, identity-based

Documentation

Document	Description
ERC Draft	Full EIP specification
Related Standards	Analysis of ERC-721, ERC-5192, ENS, ERC-6551, ERC-4337, ERC-725
URL Forwarding	On-chain URL records vs DNS, resolver architecture
Decentralized Resolution	Why SBT names don't need centralized DNS

Getting Started

Install

forge install

Build

forge build

Test

forge test

Deploy

See docs/deployment.md for deployment instructions.

Repository Structure

persistent-identity-protocol/
├── README.md
├── LICENSE
├── foundry.toml
├── EIPs/
│   └── erc-persistent-identity.md      # ERC draft
├── contracts/
│   ├── interfaces/
│   │   ├── IPersistentIdentity.sol      # Core identity interface
│   │   ├── IPersistentIdentityResolver.sol  # Resolution interface
│   │   └── IPersistentIdentityPolicy.sol    # Policy/governance interface
│   └── examples/
│       └── SimplePersistentIdentity.sol # Minimal reference implementation
├── docs/
│   ├── overview.md
│   ├── architecture.md
│   └── deployment.md
├── test/
│   └── PersistentIdentity.t.sol
└── scripts/
    └── deploy.ts

ERC Status

Draft — Preparing for Ethereum Magicians submission.

See EIPs/erc-persistent-identity.md for the full specification.

License

CC0 1.0 Universal