# Ethereum Attestation Service

> Free and open protocol for making on-chain and off-chain attestations — structured, signed, verifiable records about anything — on EVM-compatible chains.

- Readiness score: **84/100** (score.v2)
- Integration difficulty: low
- Chains: ethereum, arbitrum-one, base, optimism, polygon
- Categories: identity, attestations, reputation, data, ethereum
- Last verified: 2026-06-16 by composewith.eth research (attest.org, docs.attest.org, and ethereum-attestation-service/eas-contracts live-verified via WebFetch 2026-06-16) (confidence: high)

## Resources

- docs: https://docs.attest.org
- sdk: https://github.com/ethereum-attestation-service/eas-contracts

## Good for

- onchain reputation and credentials
- verifiable claims, badges, and eligibility records
- schema-based structured attestations
- binding signed data to identities

## Avoid for

- private data that cannot be public or hashed (attestations are public by default)
- high-volume per-event logging where onchain storage cost matters (prefer offchain attestations)
- use cases needing governance-managed revocation beyond schema-level revocability

## Capabilities

### Onchain & offchain attestations (production-ready)
Best for: issuing signed, verifiable claims about addresses or data, offchain attestations with onchain verifiability
- Onchain attestations are public; sensitive data must be kept offchain or hashed.

### Schema registry (production-ready)
Best for: defining reusable structured claim schemas, interoperable attestation formats across apps

## Composes with

- **erc-8004** (agent_identity_and_trust; supports) — EAS attestations can back ERC-8004 agent reputation and validation records with signed, verifiable claims.
- **ens** (wallet_and_identity; supports) — Attestations can be bound to ENS names to build human-readable, verifiable profiles.
- **semaphore** (governance_and_voting; supports) — Attestations can gate voter or member eligibility for anonymous signaling.
- **maci** (governance_and_voting; supports) — Eligibility attestations can define who may join a MACI poll.

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Canonical: https://composewith.eth/protocols/eas · JSON: https://composewith.eth/protocols/eas.json