category.attestations.label

category.attestations.promise

Starting path

One of these revokes by deleting, and pays whoever erases the record.

Onchain Attestations evaluated across revocation and expiry semantics, issuer permissioning and identity, verifiable chain deployments, and cost per attestation.

category.attestations.promise Reviewed on revocation and expiry semantics, issuer permissioning and identity, verifiable chain deployments, and cost per attestation.

Start with the smart category assistant or jump straight into quick questions. Both paths narrow to the same recommendation standard.

How we review

Recommendation first, comparison only if needed.

Reviewed and rechecked on the current cycle.

Commercial relationships disclosed before clickout.

Audit

Infrastructure

Methodology

2026.04.0

published 2026-04-27

Providers tracked

710+

across 80 categories

Last verified

2026-08-07

editorial freshness

Editorial board

4

audit-log live

Decision guide

What matters most before choosing in this category

Weighted on revocation and expiry semantics (32), issuer permissioning and identity (26), verifiable chain deployments (24), and cost per attestation (18). Revocation carries the most weight because it is where the category breaks quietly: Solana Attestation Service revokes by DELETING - close_attestation.rs calls attestation_info.close(), and the string "revok" appears zero times in the Attestation struct source, so after revocation the record does not exist and a consumer cannot tell a withdrawn credential from one that was never issued. The rent refund flows to whoever closes it, which means the economics reward erasing the evidence.

Key question

When a claim is withdrawn, can a consumer still see that it existed?

Key question

Who is permitted to issue, and can you establish who signed?

Key question

Are the deployments real - contract addresses you can check on an explorer?

Default starting point

Ethereum Attestation Service (EAS)

Permissionless onchain and offchain attestation registry with a schema registry, deployed on 11 EVM mainnets and shipped as an OP Stack predeploy.

Data checked Aug 2026

Permissionless onchain and offchain attestation registry with a schema registry, deployed on 11 EVM mainnets and shipped as an OP Stack predeploy. Strongest on verifiable chain deployments (10/10): The contracts page enumerates exactly 11 named mainnets under its "### Mainnets" heading — Ethereum, Optimism, Base, Arbitrum One, Arbitrum Nova, Polygon, Scroll, zkSync, Celo, Blast, Linea — with per-version addresses and explorer links, e.g. Ethereum EAS "0xA1207F3BBa224E2c9c3c6D5aF63D0eb1582Ce587" and… Weakest on issuer permissioning and identity (6/10): Revocation authority is bound to the original signer in code — EAS.sol reverts with AccessDenied on "if (attestation.attester != revoker) {" — and the Attested event indexes the attester, so the signing address is always recoverable. But issuance itself is open to any address: the FAQ describes EAS as "permissionless… Published price: "EAS is a free service. However, when making onchain attestations, users will incur gas fees, which vary based on network activity, attestation complexity, and the specific chain used. Offchain attestations, on the other hand, are completely gas-free."…

Best for

Verifiable chain deployments — 10/10Revocation and expiry semantics — 9/10Cost per attestation — 9/10

Main tradeoff

Nothing in EAS makes a schema mean anything. Anyone can attest against any schema unless the schema owner attached a resolver contract, so the buyer — not EAS — has to maintain the list of attester addresses they will honour; treating a schema UID as proof of anything is the standard way integrations get spoofed.

Verify before signup

"EAS is a free service. However, when making onchain attestations, users will incur gas fees, which vary based on network activity, attestation complexity, and the specific chain used. Offchain attestations, on the other hand, are completely gas-free." (fetched 2026-08-07)

Weighted criteria

Revocation and expiry semantics32%

Issuer permissioning and identity26%

Verifiable chain deployments24%

Cost per attestation18%

Leading options

Shared shortlist for this category

These providers are pulled from the same category comparison catalog used in validation, so the category page, comparison page, and provider reviews stay aligned.

Ethereum Attestation Service (EAS)

Permissionless onchain and offchain attestation registry with a schema registry, deployed on 11 EVM mainnets and shipped as an OP Stack predeploy.

Editor lead

Best for: Verifiable chain deployments — 10/10

Verax Attestation Registry

Consensys-maintained shared attestation registry on four EVM mainnets where issuance runs through named, registry-allowlisted Portal contracts.

Consensys-maintained shared attestation registry on four EVM mainnets where issuance runs through named, registry-allowlisted Portal contracts. Strongest on issuer permissioning and identity (9/10): Verax is the only registry in this pool that gates mainnet issuance and stores issuer identity in the protocol. PortalRegistry.sol admits new issuers only through "function setIssuer(address issuer) public onlyOwner", register() is declared "public onlyAllowlisted(msg.sender)", and the allowlist collapses to the… Weakest on cost per attestation (8/10): No protocol fee is documented and the repository ships under the MIT licence, so cost is gas plus a one-time Portal deployment. The docs confirm the zero-code path exists — "It is possible to deploy a Portal without writing a single line of code, by simply calling the `deployDefaultPortal` function on the Portal… Published price: No protocol fee is published anywhere in the repository or the issuer documentation; the README's only price-bearing statement is its licence line, "[![License](https://img.shields.io/badge/license-MIT-green)](./LICENSE)", so the cost of the registry itself…

Best for: Issuer permissioning and identity — 9/10

Sign Protocol

Permissionless omnichain attestation protocol with schema-enforced validity caps and reasoned revocation, deployed as upgradeable proxies on nine maintained EVM mainnets.

Permissionless omnichain attestation protocol with schema-enforced validity caps and reasoned revocation, deployed as upgradeable proxies on nine maintained EVM mainnets. Strongest on revocation and expiry semantics (10/10): Strongest lifecycle semantics in the pool on three counts. First, the record survives withdrawal: the Attestation data model states "This struct represents an on-chain attestation record. This record is not deleted after revocation." and keeps a revokeTimestamp plus a revoked bool. Second, revocation carries a… Weakest on issuer permissioning and identity (6/10): The signing address is bound and recoverable — the Attestation model records "`attester`: The attester. At this time, the attester must be the caller of `attest()`." and the ISP reference states of revoke that it is "Revokes an existing revocable attestation." with "Must be called by the attester."… Published price: "To fund the account balance to pay for API key usage, you can purchase credits with USDC (1 USDC = 100 Credits)." — this priced service covers decentralized storage uploads only; no fee is documented for onchain attest() or revoke() (fetched 2026-08-07)

Best for: Revocation and expiry semantics — 10/10

Browse this network

Methodology

How this category is reviewed

Reviewed on revocation and expiry semantics, issuer permissioning and identity, verifiable chain deployments, and cost per attestation.

Reviewed on: Revocation and expiry semantics, Issuer permissioning and identity, Verifiable chain deployments, Cost per attestation.

This page is a maintained category surface, not a static marketing block. Review freshness, provider positioning, and recommendation logic should stay consistent with quiz and provider pages.

Frequently asked

Questions people ask before choosing onchain attestations

What happens when an attestation is revoked?

It depends on the system, and the difference is the most consequential thing in this category. EAS records a revocationTime, so a consumer reading the record sees a claim that was made and later withdrawn. Solana Attestation Service instead closes the account: close_attestation.rs calls attestation_info.close(), the Attestation struct source contains no occurrence of "revok", and the rent refund goes to whoever performs the closure. After revocation there is nothing to read, so a withdrawn credential and one that was never issued are indistinguishable - and the party who erases it is paid to do so. This is the finding most likely to break a compliance integration silently, because nothing errors; the claim simply stops being there.

Can I rely on a big-name attestation for compliance?

Read the issuer's own terms first. Coinbase Verifications is the closest thing to institutional KYC in this pool and its integration README says the attestation "is for informational purposes only and should not be relied upon by you or any third party for any legal, compliance, or contractual purpose", adding that Coinbase "does not represent, warrant or guarantee that the information contained in any attestation or represented thereby is complete, accurate, or current." The schemas are revocable onchain - verified by eth_call to the Base SchemaRegistry predeploy, returning revocable true for all three - yet the words "revoke", "revocation", "expiry" and "expiration" appear zero times in that 10,341-byte README. The capability exists and the documentation never tells an integrator how it behaves.

Are these deployments as decentralised as they look?

Not always, and the check is cheap. Sign Protocol's maintained deployments across nine mainnets are upgradeable proxies owned by a single address: eth_getCode for that owner returned exactly "0x" on both Ethereum and Base, meaning an externally owned account rather than a multisig. All nine proxies return identical bytecode, so one key can replace attestation logic on nine chains at once. Separately, cost is worth checking against the chain rather than the price list: Human Passport charges $2 to write an attestation whose measured onchain cost the same day on the same L2 was $0.004319, a 463x markup, for a score that carries no expiry field - "Onchain scores do not have an explicit expiry date associated with them."

REVIEWEDApr 2026METHOD4 criteriaCATEGORYattestations

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