crypto dog tags

Inspiration

Physical military dog tags symbolize identity and belonging. We wanted to bring that same symbolism on-chain — a portable, verifiable proof of who you are in crypto, beyond wallet addresses or ENS names.

What it does

Crypto Dog Tags are soulbound NFTs that encode key wallet metadata and social proofs (e.g. GitHub commits, on-chain activity, DAO membership). They serve as readable, verifiable ID badges across chains and dApps.

How we built it

We used Solidity to create a non-transferable ERC-721 smart contract with metadata dynamically generated via an off-chain worker (Node + Supabase). The metadata includes verifiable signatures for linked accounts. The frontend was built in Next.js with Wagmi and RainbowKit for wallet connection.

Challenges we ran into

• Ensuring non-transferability without breaking compatibility with NFT marketplaces.
• Handling cross-chain identity proofs without centralization.
• Designing metadata updates that remain cryptographically verifiable.

Accomplishments that we’re proud of

• Fully on-chain issuance and verification with no custodial backend.
• Smooth UX for minting and linking social accounts.
• A clean, futuristic aesthetic that feels both collectible and functional.

What we learned

• Soulbound mechanics require careful contract design to avoid lock-in bugs.
• Cross-chain identity is messy without a universal standard; users value control over self-representation.
• Presentation matters — tangible, game-like metaphors help people understand crypto identity.

What’s next for Crypto Dog Tags

• Expand to multi-chain verification (Solana, Base).
• Integrate Lens and Farcaster handles as badges.
• Add optional ENS-style vanity naming.
• Collaborate with hackathons and DAOs to issue event-specific tags as identity primitives.

Built With

• sophia