Anchor Service Registry ◈︎

AIOSchema Anchor Service Registry

Version: v0.5.6 Status: Active Governance: Registry Governance

Overview

AIOSchema anchor services provide cryptographic timestamps that establish when a manifest existed. The anchor_reference field in a manifest uses the URI scheme:

aios-anchor:<service-id>:<anchor-id>

service-id is the registered identifier for the anchor service. anchor-id is the service-specific record identifier.

Registered Anchor Services

Service ID	Provider	Mechanism	Discovery URL	Status
`rfc3161`	RFC 3161-compliant TSA	RFC 3161 trusted timestamp	Per-service well-known URL	Active
`ots-bitcoin`	OpenTimestamps	Bitcoin blockchain attestation	Per-service well-known URL	Active

Services publish their discovery document at:

https://<service-domain>/.well-known/aioschema-anchor.json

The discovery document MUST include the service name and supported anchor schemes. It SHOULD include a public verification endpoint URL.

Requirements for Registration

An anchor service MUST satisfy all of the following to be registered:

Publicly verifiable: any third party can independently verify an anchor record without relying on the service operator.
Independent of the content author: the anchor is produced by a party with no interest in the content being anchored.
Immutable: once created, an anchor record cannot be altered or deleted.
Timestamped: the anchor produces a record establishing a specific point in time.
Discovery document published at the well-known URL.
anchor_resolver contract satisfied per Specification §9.2.

Anchor Resolver Contract

A conforming anchor resolver accepts an aios-anchor: URI and returns a record containing at minimum:

Field	Type	Description
`asset_id`	String	Must match the manifest `asset_id`
`core_fingerprint`	String	Must match the manifest `core_fingerprint`
`timestamp`	String	ISO 8601 UTC timestamp of anchor creation
`signature`	String or null	Ed25519 signature value at anchor time, if stored

Verification succeeds when asset_id and core_fingerprint both match using timing-safe comparison.

Proposing a New Anchor Service

Use the proposal process.