Reimagining Digital Identity: Self x Spire on Celo

As the boundaries between humans and AI blur, verifying real human presence online has never been more important. Deepfakes, automated bots, and AI-generated identities are challenging trust, authenticity, and safety across the internet. Self Protocol offers a scalable solution: a privacy-preserving identity layer built on zero-knowledge proofs that allows anyone to verify their humanity without revealing personal information. By embedding this cryptographic Proof of Humanity directly into blockchain infrastructure, Self provides a defense against AI-driven impersonation, ensuring that users, creators, and communities can distinguish genuine human activity from synthetic ones—securely and transparently.

A New Identity Layer for the Onchain World

The collaboration between Self and Spire marks a major step forward for decentralized digital identity and onchain interoperability. Together, they’ve built the first synchronously composable appchain on Celo, a milestone demonstrating how privacy-preserving, human-verified interactions can thrive within a unified Ethereum Layer 2 ecosystem.

Built on Spire: Synchronous and Composable

At the core of this launch lies Self’s zero-knowledge Proof of Humanity (ZK PoH), a mechanism that enables users to verify their humanity and identity attributes onchain — without exposing sensitive personal data. This capability, now embedded directly into Spire’s Pylon platform, allows any appchain to integrate human verification natively and securely.

Whether proving uniqueness, confirming age eligibility, or verifying nationality, Self empowers users to share only the proof, not the personal data behind it. This shifts identity ownership back to users while enabling applications to enforce compliance, fairness, and access control in a fully private way.

Unlocking New Use Cases

The launch of the Human Appchain, built with Self and Spire, introduces a powerful new concept: the Human NFT — a verifiable, privacy-preserving proof of humanity minted directly on Celo. Once verified through Self’s zero-knowledge Proof of Humanity, each user can mint a unique Human NFT representing their digital authenticity. This NFT acts as a reusable passport for the onchain world, confirming one’s humanness without ever exposing personal details.

The Human NFT and this privacy-preserving proof of humanity open the door to a broad range of future applications across the ecosystem:

• Verified participation in communities and governance — gate voting or community membership, ensuring that every voice belongs to a real person.

• Fair airdrops and reputation systems — reward engagement and loyalty based on human participation rather than bots or multi-account farming.

• Identity-aware DeFi — enable credit scoring, secure lending, or real-world asset access built on verified human identity.

• Privacy-compliant payments and stablecoin flows — integrate human verification for regulatory assurance without revealing users’ private data.

• Safe social and age-gated experiences — allow builders to create apps that respect compliance and user privacy at once, from gaming to digital identity-enabled metaverses.

• Wallet recovery and authentication — a cryptographic backup for restoring access or verifying rightful ownership.

The minting of the Human NFT marks the beginning of a more trustworthy onchain ecosystem, one where identity becomes an enabler, not a barrier. By leveraging Self’s verification solution and Spire’s synchronous composability, developers can seamlessly build experiences where being human is both verifiable and private, forming the blueprint for the next wave of decentralized applications.

Why Celo

As one of the most active Ethereum Layer 2s, Celo is designed for real-world usability: fast transactions, low fees, and a mobile-first user experience. Spire and Self chose Celo because of its scalability, thriving ecosystem, and vision for a unified Ethereum future — one where economic coordination and human identity converge sustainably.

The Path Forward

This partnership is only the beginning. By embedding Self into an appchain using Spire, builders can now integrate Proof of Humanity directly into their dApps, no custom infrastructure, no fragmentation, just composable identity at the protocol layer. The potential spans finance, governance, gaming, social, and beyond.

As synchronous composability becomes the new standard for cross-chain UX, Self x Spire on Celo stands as a blueprint for a more connected, compliant, and human ecosystem.

Mint your one and only Human NFT on Spire now: https://human.spire.dev/