An onchain reputation passport is a soulbound NFT on Base that reads a wallet's history and turns it into a single, shareable reputation card. You build it by pulling verifiable signals like Coinbase Verifications, a Basename, transaction age, and Talent Protocol Builder Score, then minting a non-transferable token that renders those signals as a clean card anyone can view. It is a beginner-friendly consumer app, and it is one of the clearest ways to prove you can read onchain data, work with attestations, and ship a real product on Base.
What you are building and who it is for
The product is simple to describe and useful to hold. A user connects a wallet, your app scans that address for a set of reputation signals, and it mints them a soulbound NFT that displays a reputation card. The card is non-transferable on purpose, because reputation should belong to the person who earned it and cannot be bought or sold.
This is a consumer app for everyday onchain users who want a portable identity: someone who has held a wallet for two years, verified with Coinbase, registered a Basename, and wants a badge that says so. It is also a beginner build for developers, because the hard parts are already public infrastructure. You are composing existing primitives, not inventing cryptography.
Why this positions you as a Base developer
Base cares a lot about identity and reputation, and the ecosystem has shipped the exact tools this project uses. Coinbase Verifications issues Coinbase-verified onchain attestations on Base using the Ethereum Attestation Service, an open-source public good included as a predeploy in the OP Stack. Building on top of Verifications and EAS shows you understand the identity layer Base is actively investing in.
You also touch the parts of the stack Base evangelizes to builders: OnchainKit for wallet connection and Basename resolution, and reading real attestation data rather than mocking it. Talent Protocol's Builder Score has been integrated by protocols like Base and Etherscan to add reputation context, so wiring it in shows you know the reputation graph, not just the theory. A finished reputation passport is a portfolio piece that says you can read chain state, verify attestations, and ship a consumer flow. That is exactly the kind of real, provable work that airdrops and grant programs look for, and the kind of thing you can showcase on a DEPLOYR storefront at /.
A concrete build path and stack
Start with the stack Base recommends so you are not fighting the toolchain.
Core stack
- Next.js with TypeScript for the app.
- OnchainKit for wallet connection, identity, and Basename resolution. It ships pre-built React components so you can get a working connect flow in minutes.
- The EAS SDK to read attestations. Coinbase Verifications live on Base under the ENS domain verifications.coinbase.eth, so you can query whether an address holds a verified-account or country attestation.
- A public data API (for example an indexer or a node provider) to read wallet age, transaction count, and first-transaction date.
- A soulbound NFT contract following ERC-5192, the minimal soulbound standard, where every ERC-721 transfer function reverts so the token cannot move.
Build steps
- Ship the connect flow first. Use OnchainKit to connect a wallet and resolve its Basename. This alone is a working screen you can demo.
- Read the signals. Query the EAS SDK for Coinbase Verifications on the connected address, pull the Basename, and read wallet age and transaction count from your data provider. Keep each signal a small, testable function.
- Score and render. Turn the raw signals into a simple, transparent score and render a reputation card as an image or SVG. Make the scoring rules visible so users trust the number.
- Mint the passport. Deploy an ERC-5192 contract, using OpenZeppelin's ERC-721 as the base and reverting on transfer. Store the card metadata and let the user mint their own passport.
- Make it shareable. Add a public view page per token so a card can be posted anywhere. Shareability is the whole point of a passport.
Ship steps 1 through 3 as a read-only demo before you write a single line of contract code. A working card that reads real data is already impressive, and it de-risks the minting work.
Common pitfalls
- Confusing attestations with tokens. EAS attestations are flexible offchain-or-onchain records; a soulbound NFT is an ERC-721 that cannot transfer. Your passport can read attestations as inputs and still mint an ERC-5192 token as output. Do not try to make EAS do the NFT's job.
- Making the token transferable by accident. ERC-5192 requires that every transfer function reverts. Test this explicitly. A reputation token that can be sold is not reputation.
- Trusting one data source. Wallet age and transaction counts can differ across providers. Pick one provider, document it, and be honest in the UI about what each signal means.
- Opaque scoring. If users cannot see why they got a score, they will not share the card. Show the inputs.
- Sybil naivety. A fresh wallet with a bought Basename is not reputation. Weight hard-to-fake signals like Coinbase Verifications and wallet age more than cheap ones.
- Over-promising rewards. Do not imply the passport earns anyone an airdrop. It is a credential, not a payout.
How DEPLOYR builds and ships it with you
DEPLOYR exists to help you become the real onchain developer that airdrops look for, and this project is a strong first build. We can scope the passport with you, set up the OnchainKit and EAS stack, help you write and test the ERC-5192 contract so it actually reverts on transfer, and get the shareable card live on a storefront you own. You walk away with a deployed app, a public link, and a portfolio piece that proves you can read and write onchain, not just talk about it.
If you want to go deeper on Base tooling and reputation, read more at /insights, plan your build at /build, and look for events to ship it at /hackathons.
Ready to ship your reputation passport? Start at /build and put a real, working app on your storefront at /.
Airdrops are never guaranteed. No guide, credential, or build promises a payout. What this gets you is real, provable developer work, which is the thing worth owning either way.