BNB Attestation Service

• Name: BNB Attestation Service (BAS)
• URL: https://docs.bnbchain.org/showcase/identity/attestation/
• Category: attestation infrastructure / schema-and-resolver middleware / BNB identity primitive
• Tags: bnb-ecosystem
• Summary: BAS is BNB Chain’s local attestation rail. The split is simple: schemas define shape, resolvers decide admission, and Greenfield carries the bulky records when BNB Chain should not. Useful middleware, mostly ecosystem-local, not a branch anchor.
• What it does:
  • Lets users define arbitrary attestation schemas, including optional resolver contracts that add custom issuance logic
  • Supports chain-stored attestations on BNB Chain plus Greenfield-backed records when keeping the full payload out of chain state is cleaner
  • Treats schemas as reusable data definitions and resolvers as hook points for payment, eligibility, or other policy checks
  • Exposes attestation records with unique UIDs, decoded schema data, status, and reference relationships
  • Positions itself as general attestation middleware for identity, reputation, KYC, and related data-import use cases
  • Ships first-party examples around privacy-preserving KYC and developer reputation, which makes clear BAS is meant to be embedded into other BNB identity flows rather than stand alone
• Key claims:
  • The official BNB Chain docs present BAS as reusable attestation infrastructure, not just one feature inside the ecosystem stack.
  • BAS splits schemas, attestations, and resolvers cleanly, so data shape, issuance, and policy are not bundled into one opaque object.
  • Anyone can define schemas and attach resolver logic, which means issuer openness depends on per-schema configuration rather than on BAS as a whole.
  • The docs support both chain-stored attestations and Greenfield-backed records, so storage placement is part of the real design choice rather than an implementation footnote.
  • The result looks like competent schema-and-resolver middleware, but not a category center beyond the BNB branch.
• Whitepaper: No standalone BAS whitepaper or litepaper surfaced in this pass. The strongest primary materials were the official BNB Chain and BAS docs plus the linked contract repository, collected in ../whitepapers/bnb-attestation-service-primary-sources-2026-05-11.md.
• Sources:
  • https://docs.bnbchain.org/showcase/identity/attestation/
  • https://doc.bascan.io/core_concept/schema
  • https://doc.bascan.io/core_concept/attestation
  • https://doc.bascan.io/core_concept/resolver
  • https://github.com/bnb-attestation-service/bas-contract

Internal linkages

• Best upward reads: ethereum-attestation-service and sign-protocol. Keep the note on schema-and-resolver middleware, not generic BNB identity marketing.

Control surface

• Control sits in schema design, resolver logic, Greenfield-versus-chain storage choice, and which BAS attestations downstream apps or indexers treat as worth reading.

• The useful question is who sets issuance policy and where the meaningful data custody actually lives.

• Last reviewed: 2026-06-18 UTC