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What is an Attestation?

A signed statement by an issuer about a subject, stored on-chain. Example: “KYC Provider X attests that Wallet Y is verified at level Basic”

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Attestation Properties

PropertyDescription
uidUnique identifier (32 bytes)
schemaUidReference to schema structure
attesterWho created the attestation
subjectWho the attestation is about
valueAttestation data (JSON string)
timestampWhen created
expirationTimeWhen it expires (optional)
revokedWhether invalidated

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Lifecycle

Created ──▶ Active ──▶ Expired
                │
                └──▶ Revoked
Created: Attestation issued and stored on-chain Active: Valid and queryable Expired: Past expiration time (still on-chain) Revoked: Explicitly invalidated by attester

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Use Cases

  • KYC/Identity: Verify user identity
  • Credentials: Professional certifications
  • Reputation: On-chain reputation scores
  • Access Control: Gate access to services
  • Compliance: Regulatory attestations

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Schema Relationship

Every attestation references a schema that defines its structure: 
// Schema defines structure
'struct KYC { bool verified; string level; }'

// Attestation follows structure
{ verified: true, level: 'basic' }

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Next Steps

Schemas

Learn about schema design

Delegates

Off-chain signing with BLS keys