Features

Comprehensive Profile Management

ERC-7866 provides a complete identity layer for Web3 applications.

Unique Usernames

Claim a human-readable, globally unique identifier tied to your address:

profile.createProfile("alice", "ipfs://avatar...");

Benefits:

• Easy to remember and share
• Immutable (cannot be changed)
• Prevents username squatting through first-come-first-served
• Reverse lookup: username → address

Multi-Avatar System

Set different avatars for different contexts:

// Default avatar (used everywhere by default)
profile.setDefaultAvatar("ipfs://professional-avatar...");

// dApp-specific avatars
profile.setDappAvatar("GameA", "ipfs://game-character...", true);
profile.setDappAvatar("GameB", "ipfs://different-avatar...", true);

Use cases:

• Gaming: In-game character avatars
• Professional: LinkedIn-style work avatar
• Privacy: Keep sensitive avatars private
• Branding: dApp-specific character customization

Privacy Control

Mark avatars as public or private:

// Public avatar - anyone can see
profile.setDappAvatar("PublicDApp", "ipfs://...", true);

// Private avatar - only owner can see
profile.setDappAvatar("PrivateDApp", "ipfs://...", false);

Privacy enforcement happens at function level:

• Private avatars return empty URI to non-owners
• No special setup needed
• Works across chains

Multi-Chain Identity

Same username and address across multiple blockchain networks:

Ethereum:  alice@eth.soul      → 0xAlice
Polygon:   alice@polygon.soul  → 0xAlice
Arbitrum:  alice@arb.soul      → 0xAlice

Deploy SoulProfile to each network and users maintain consistent identity.

Soul Bound (Non-Transferable)

Profiles are bound to addresses and cannot be transferred:

• Profile is tied to the address that created it
• Immutable core data (username, creation address)
• Only owner can modify
• Cannot be sold or transferred
• Survives wallet changes through recovery mechanisms

Event-Driven

Complete event logging for profile changes:

event ProfileCreated(address indexed owner, string username);
event DefaultAvatarUpdated(address indexed owner, string avatarURI);
event DappAvatarSet(address indexed owner, string dappName, string avatarURI, bool isPublic);
event DappAvatarRemoved(address indexed owner, string dappName);

Applications can:

• Listen for new profiles
• Track avatar updates
• Build real-time discovery systems
• Index profiles for search

Off-Chain Storage

Minimize on-chain footprint with off-chain metadata:

Contract stores:
├── username (string)
├── defaultAvatarURI (pointer to IPFS/Arweave)
├── dAppAvatars (mapping of URIs)
└── visibility flags (boolean)

IPFS/Arweave stores:
├── avatar image
├── bio
├── website
├── social links
└── dApp-specific metadata

Benefits:

• Lower gas costs for profile creation
• Larger metadata capacity
• Decentralized storage
• Immutable history on IPFS

Resolver Pattern

Optional helper contract for safe profile discovery:

SoulProfileResolver resolver = new SoulProfileResolver(address(soulProfile));

// Resolve with privacy checks
string memory avatar = resolver.resolveDappAvatar(userAddress, "MyDApp");

// Resolve only public avatars
string memory publicAvatar = resolver.resolveDappAvatarPublic(userAddress, "MyDApp");

// Resolve username
string memory username = resolver.resolveUsername(userAddress);

Security Guarantees

• Non-transferable: Soul bound to address
• Immutable usernames: Cannot be changed after creation
• Privacy enforced: Private data hidden at function level
• Reentrancy safe: State changes before external calls
• Ownership verified: Only owner can modify profile