TL;DR

• Human Passport protects Citizens’ House Season 8 on Optimism, enabling one-person-one-vote governance based on identity and onchain reputation instead of token holdings.

• Users need a Passport score of 20+, earned via verifiable credentials (Stamps) from onchain and offchain activities, no invasive KYC required.

• Human Passport previously secured the Superchain Faucet, gating access to real users and blocking bots by requiring users to mint their Humanity Score onchain to OP.

• We offer a full Sybil resistance toolkit on Optimism, including:

Optimism’s bicameral governance system, an ongoing experiment in non-plutocratic governance and public goods funding, is now enrolling Superchain end users as governance participants in Season 8 of the program. Each user gets a vote in a one-person-one-vote system, empowering individuals without significant token holdings, but with sufficient onchain activity to meaningfully influence collective decisions.

To qualify, individual users must reach a Human Passport score of 20 or higher, earned by collecting identity “Stamps” — verifiable credentials aggregated from onchain activity, social attestations, KYC, biometrics, and other credible sources. This introduces onchain proof-of-personhood as a gating mechanism for participation in Optimism Governance. Alternatively, users may verify their identity using World ID.

The Citizens House plays a structurally important role by allocating shared resources, exercising veto authority, and deriving legitimacy from identity and reputation rather than capital. Proof of Personhood ensures that this influence is exercised by real, unique individuals, thereby strengthening both the integrity and inclusivity of the system.

Plutocracy, Sybil Risk & the Identity Dilemma

Token-based governance has long been vulnerable to plutocracy by design, where one-token-one-vote systems let concentrated wealth dominate outcomes. Small holders can be left out, and real participation suffers through low turnout, apathy from minor stakeholders, and recurring “tyranny of the whales.”

Outside the Optimism ecosystem, these dynamics have played out in practice. Humpty the whale was able to unilaterally sway a major governance vote in Compound by concentrating token power at the last minute. Similarly,  Octant’s public goods funding round has shown how just one or two big holders can override broader community intent, shifting outcomes in the final moments despite widespread support from smaller donors.

Optimism’s bicameral governance structure separates token voting through the Token House and identity-based voting through the Citizens’ House, which adds a pragmatic balance designed to resist capture while accommodating room for experimental governance. But in a pseudonymous ecosystem, proving uniqueness without forcing KYC presents a real challenge. Traditional KYC compromises privacy; pseudonymity without Sybil resistance opens the door to mass manipulation.

This creates a dilemma: without personhood, equity fails; with invasive identity checks, decentralization is flattened.

To meet these challenges, Human Passport has made available its full Sybil resistance infrastructure on Optimism through a modular toolkit, including Passport Models, Passport Stamps, and Data Services – tools used in Citizens House Season 8 and Optimism’s other campaigns.

Real-World Sybil Resistance for a Human-Centric Superchain

Human Passport has a long-standing presence in the Optimism ecosystem, supporting Sybil-resistance efforts across Citizens House, faucet protection, and multiple token incentive campaigns. Our tools have already been deployed in live Optimism campaigns to ensure participation reflects real users.

Below are two examples where identity-based verification has protected governance and infrastructure from Sybil manipulation.

Citizens’ House: Proof of Humanity (PoH) for One-Person-One-Vote Governance System

Optimism’s bicameral system separates token-weighted influence from identity-based participation, a large-scale experiment aimed at addressing the persistent risks of plutocracy in onchain governance.

In Season 8, Citizens’ House will be represented by chain operators, dApp builders, and up to 1,000 end users, each selected based on credible, sustained onchain activity. This is based on the principle that individuals or groups who have a legitimate interest or claim in the use, management, and sustainability of a common-pool resource should be the ones to govern those resources.

To preserve the integrity of this one-person-one-vote model, Human Passport is used to verify unique individuals without requiring invasive KYC. Participants must reach a Passport score of 20 or more, earned by aggregating Stamps tied to behavioral, social, and optionally biometric or zk KYC credentials.

This implementation strengthens the Citizens’ House in its dual mandate: acting as a legitimacy layer for Optimism’s governance, and exercising structural checks on the Token House through veto power and resource allocation. The result is a more robust, inclusive, and capture-resistant governance process, rooted in identity, not only capital.

Superchain Faucet: Keeping Developer Tools Human

The Superchain Faucet is a developer tool hosted by Optimism that provides free testnet ETH for builders testing applications on OP testnets. Like many open-access testnets, it was vulnerable to Sybil attacks, botnets draining funds intended for legitimate use.

To address this, Human Passport was integrated into the faucet flow. Users are required to hold a score above 20 and mint their Passport onchain on Optimism to access funds. This threshold was chosen as an effective baseline, difficult for Sybil networks, yet achievable for real users through organic activity or trusted credentials.

Human Passport successfully protected the Superchain Faucet, preventing exploitation while preserving access for genuine developers across the OP ecosystem.

The Full Optimistic Toolkit by Human Passport

Human Passport supports Optimism builders with the full range of its products and services: from Stamps and Models, to Data Services, zk KYC, and minting passport scores onchain. Below, we explore some of these tools in detail.

Passport Models: ML-Powered Sybil Detection for OP

As part of our pursuit to build Sybil-resistant infrastructure for the Optimism ecosystem through modular tools, Human Passport has developed a chain-specific supervised machine learning model that can be used to classify addresses as either human or Sybil. Trained on real-life OP Mainnet data, this model continuously analyzes wallet behavior, such as activity patterns, contract usage, and engagement timelines, to assess whether a user is likely a unique individual or part of a Sybil network.

Unlike manual verification flows, model-based Sybil detection works passively in the background. Wallets are scored without requiring users to collect Stamps or take any other explicit action. Based solely on public onchain data, the model assigns each wallet a Unique Humanity Score from 0 to 100, reflecting how closely its behavior matches known human vs. Sybil patterns.

Optimism builders can use this score to apply Sybil resistance in a variety of contexts, from faucet gating to airdrop qualification to trust-weighted access. The scores can be accessed offchain, via API, or directly onchain, using Onchain Passport (provided that users minted their scores onchain!).

This OP-specific model is paired with an aggregate model that pulls in behavioral signals from multiple chains. Together, they improve classification accuracy and capture Sybil activity that spans ecosystems. The models are continuously iterated and their mechanics are undisclosed, to stay ahead of Sybil's infinite and evolutionary approach.

Onchain Passport: Discover onchain Identity via EAS

Within the Optimism ecosystem, Human Passport leverages the Ethereum Attestation Service (EAS) to mint structured, verifiable identity credentials directly onchain.

Once a user reaches a Passport score of 20 or higher, they can issue an attestation to OP Mainnet that proves Sybil resistance, without revealing personal information onchain. This has significantly bolstered trust in Optimism, driving a significant number of attestations on EAS and data availability for everyone in the OP ecosystem. As a result, more than 61,624 of passports have been pushed to the OP Mainnet.

Unlike NFTs or SBTs, which are often difficult to discover, EAS stores attestations in a shared, open registry. This makes them instantly queryable by any smart contract, UI, or indexing tool across the OP Stack. Developers only need to integrate once to access attestations from multiple sources, simplifying integration and enabling richer onchain logic.

Each attestation is tied to a structured schema: machine-readable, human-legible, and extensible. This design opens up broad use cases: not just governance, but quadratic funding, contributor rewards, access control, trust scoring, and airdrop eligibility—all composable, and fully onchain.

Learn more about how to mint Passport score onchain to Optimism and how partners can access this data to protect programs completely onchain.

• For users: Mint your Passport score onchain

• For partners: Retrieve Humanity Score directly onchain

Human Passport’s Impact on the OP ecosystem

Human Passport has supported a range of successful Sybil-resistant campaigns and token incentive programs across the Optimism ecosystem. Over 61,624 Passports have been minted onchain to OP Mainnet using Stamps-based identity verification, resulting in a total of  84,652 OP attestations accessible via smart contracts. In ShapeShift’s incentive rollout, the system disqualified more than 5,700 Sybil-linked addresses, preserving over 45,000 OP tokens. Additional integrations with Tide and Bankless Academy have further strengthened trust in reward distribution and community engagement.

In this article, we looked at two examples where these tools have been directly implemented: the Citizens’ House one-person-one-vote integration and OP’s faucet protection.

How to Get Started with Human Passport on Optimism

Human Passport’s integration is simple. Optimism projects can start scoring wallets immediately using our API. In general, we offer tools that meet teams where they are:

• Models API: call our models directly to score wallets.

• Stamps API and Smart Contracts: retrieve data related to our aggregate ID verification product, both onchain and off.

• Passport Embeds (coming soon): embeddable React component that can be used to verify users directly on your website - early access here.

• Data Services: Sybil classification and clustering of lists of addresses.

Interested teams can visit the developer docs to explore technical integration, check Human Passport’s use cases, or reach out to us for tailored support!

Send us a partnership request or sign up for early embed testing using our contact form.

About Human Passport (formerly Gitcoin Passport)

Human Passport is an identity verification application and Sybil resistance protocol with more than 2M users. It enables users to collect verifiable credentials, or Stamps, that prove their identity and trustworthiness without exposing personally identifying information. To date, Human Passport has protected over $430M in airdrop and grant funds.

https://passport.human.tech

About human.tech

human.tech is a suite of technologies designed to enhance personal freedom, privacy, and financial autonomy. human.tech provides innovative solutions for secure identity, data ownership, and private transactions, ensuring that technology remains a tool for human empowerment.

https://human.tech