Attestation Station

• Name: Attestation Station (ATST)
• URL: https://github.com/ethereum-optimism/optimism-starter/blob/main/attestation-station.md
• Category: minimal attestation registry / onchain key-value claims store / Optimism identity primitive
• Tags: ethereum-ecosystem
• Summary: Attestation Station is a bare claims log. It stores creator / subject / key / value, lets anyone write, and leaves schema discipline, issuer filtering, indexing, and trust interpretation to everything around it. Useful floor case, nothing more.
• What it does:
  • Stores attestations in a three-level mapping keyed by creator, subject (about), and bytes32 key
  • Lets any caller write a single attestation or batch multiple attestations in one transaction
  • Treats the attested payload as arbitrary bytes, so the contract does not enforce a shared schema format
  • Emits an AttestationCreated event for each write, making external indexing and interpretation straightforward
  • Provides a lightweight SDK / CLI / hackathon-oriented integration surface in Optimism’s starter materials
  • Encourages ecosystem-specific keys, conventions, and indexers rather than embedding resolver logic or issuer governance onchain
• Key claims:
  • The official Optimism starter docs describe Attestation Station as being “as simple as possible,” which is the main reason to keep it: it is minimal claims infrastructure, not a full identity stack.
  • Every record is just Creator, About, Key, and Val. That makes the note useful because it shows the lower bound underneath richer attestation systems.
  • The reviewed contract stores data in mapping(address => mapping(address => mapping(bytes32 => bytes))), so the base layer only tracks who said something, about whom, under which key, with what raw bytes.
  • Anyone can call attest, and batching is supported. Issuer admission is therefore open at the contract layer; trust filtering happens elsewhere.
  • The contract has no schema registry, resolver hook, native revocation system, or issuer allowlist. That absence is the point.
  • Writes overwrite the same creator/about/key slot, so this behaves more like a mutable namespaced claim store than an immutable credential ledger.
  • The starter materials surface SDK, CLI, and indexer tooling, which reinforces the real model: many downstream readers, not one canonical frontend.
• Whitepaper: No standalone Attestation Station whitepaper or litepaper surfaced in this pass. The strongest primary materials were the official Optimism starter documentation and the reviewed contract source collected in ../../whitepapers/attestation-station-primary-sources-2026-05-11.md.
• Sources:
  • https://raw.githubusercontent.com/ethereum-optimism/optimism-starter/main/attestation-station.md
  • https://raw.githubusercontent.com/ethereum-optimism/optimism-starter/main/contracts/src/AttestationStation.sol
  • https://raw.githubusercontent.com/ethereum-optimism/optimism-starter/main/README.md

Internal linkages

• Best upward comparison points for richer attestation rails: ethereum-attestation-service and verax.

Practical control points

• Control is mostly outside the contract: key naming conventions, issuer allowlists, indexer policy, and which readers decide a given creator / subject / key / value tuple means anything.

• That is why the note is worth keeping. It shows how much of attestation infrastructure usually lives outside the contract.

• Last reviewed: 2026-06-13 UTC