Gitcoin Passport

Gitcoin Passport is a self-sovereign identity tool that allows users to collect stamps—verifiable attestations from various web2 and web3 platforms—into a single, portable identity. These stamps, which are Verifiable Credentials (VCs), can prove attributes like owning a specific NFT, having a certain social media account age, or completing a Proof of Humanity check. The aggregated stamps are scored by the Gitcoin Passport Scorer to generate a unique Passport Score, a quantitative measure of a user's trustworthiness and uniqueness within a system. This score is crucial for applications needing to distinguish real, unique users from automated bots or duplicate accounts.

The primary use case for Gitcoin Passport is securing quadratic funding rounds, such as those on the Gitcoin Grants platform. By requiring a minimum Passport Score to participate, the protocol effectively mitigates Sybil attacks, where a single entity creates multiple fake identities to manipulate funding outcomes. This ensures a more fair and democratic distribution of community funds. Beyond funding, Passport is increasingly integrated into DAO governance systems, token-gated experiences, and airdrop eligibility checks, providing a reusable layer of trust and reputation across the decentralized web without relying on centralized authorities.

Technically, a user's Passport is represented by a Decentralized Identifier (DID) stored on the Ceramic Network, a decentralized data stream protocol. Stamps are issued by issuers (like BrightID, ENS, or Coinbase) and held in the user's identity wallet. The scoring algorithm, which can be customized by applications, weights different stamp types to calculate the final score. This modular, composable architecture allows any dApp to query a user's score via an API to make permissioning decisions, making Gitcoin Passport a foundational Sybil resistance primitive for the broader web3 ecosystem.

Gitcoin Passport functions as a self-sovereign identity aggregator. Users connect various accounts—such as Google, Twitter, GitHub, or blockchain wallets—to collect verifiable credentials (VCs) known as stamps. Each stamp is a cryptographically signed attestation from a specific provider, proving a user's action or attribute, like account age or transaction history. These stamps are stored locally in the user's browser or a decentralized storage service, giving the user full control over their data. The core mechanism is the Passport Scorer, an API that calculates a user's unique Humanity Score by applying a weighted algorithm to their collected stamps.

The scoring process is transparent and configurable. Application developers, or scoring partners, define a scoring rubric that assigns specific weights to different stamps based on their trust requirements. For example, a Sybil-resistant grant round might heavily weight a Bright ID stamp or Proof of Humanity verification, while a community governance platform might prioritize GitHub commits or Guild.xyz membership. The Passport Scorer API fetches a user's stamps, applies the partner's specific algorithm, and returns a single score. This allows platforms to implement graduated access controls, granting privileges based on score thresholds without exposing the user's underlying personal data.

Integration for developers is streamlined through the Gitcoin Passport API and software development kits (SDKs). A dApp can embed a Passport widget to initiate the stamp collection process. Once a user has a score, the dApp's backend can query the Scorer API to verify the user's eligibility. This architecture separates identity verification from application logic, allowing any platform to leverage a shared, composable reputation layer. Key use cases include filtering Sybil attacks in quadratic funding, gating token airdrops to unique humans, and creating trusted environments for decentralized autonomous organizations (DAOs).

Underpinning the system is a commitment to privacy and user agency. Stamps are zero-knowledge credentials where possible; the Passport Scorer only receives the stamp's type and issuance date, not the underlying data (e.g., your Twitter handle). Users can choose which stamps to reveal and can delete their Passport data at any time. The protocol is built on Ethereum Attestation Service (EAS) standards, ensuring stamps are portable, interoperable, and verifiable across the broader decentralized identity ecosystem. This establishes Gitcoin Passport not as a closed system, but as an open, composable primitive for web3 trust.

Gitcoin Passport is a decentralized identity protocol that aggregates verifiable credentials from various web2 and web3 sources into a single, user-controlled identity to prove humanness and reputation while preserving privacy. It functions as a sybil resistance tool, allowing applications to assess the likelihood that a user is a unique human rather than a bot or duplicate account. Users collect stamps—attestations from identity verifiers like BrightID, ENS, or Coinbase—which are stored as Verifiable Credentials (VCs) in their Passport. The protocol's core innovation is its scoring mechanism, which calculates a Passport Score based on the accumulated stamps, enabling platforms to implement gated access or weighted governance.

The technical architecture is built on a decentralized data model where users retain custody of their credentials. Stamps are stored off-chain, typically in a user's Ceramic data stream or compatible decentralized storage, and are cryptographically signed by the issuing verifier. When a user connects their wallet to an application, they present their Passport, and the application's backend queries the Gitcoin Passport API or a Scorer service to verify the stamps and compute a score. This design separates the identity layer from the application layer, allowing for composability; a single Passport can be used across multiple dApps, DAOs, and grant platforms without creating new accounts.

Under the hood, the scoring algorithm uses a weighted model where different stamps contribute different point values based on their perceived cost-of-attack and reliability for proving unique humanness. For example, a Proof of Humanity stamp carries significant weight, while a social media verification may contribute less. Applications set their own score thresholds for access. The protocol is evolving towards greater decentralization with the Passport Protocol, an open-source framework that allows any community to run its own passport instance and scoring logic, moving away from a centrally managed API to a self-sovereign standard.