Data Model

This page defines the core types and structures that make up the SIG protocol. All JSON field names use snake_case.

OreMetadata

The issuer’s metadata object, served at /.well-known/sig-metadata.json. This is the entry point for discovery.

Field	Type	Required	Description
spec_version	string	Yes	Protocol version. Must be "sig/0.1".
issuer	string	Yes	The issuer’s canonical DID, e.g. "did:web:acme.example".
jwks_uri	string	Yes	Absolute URL to the issuer’s JWKS endpoint.
events_uri	string	Yes	Absolute URL to the NDJSON event feed.
public_only	boolean	Yes	If true, all events in the feed are public. If false, the feed may contain events with "private" visibility.
algorithms_supported	string[]	Yes	List of supported JWS algorithms. Must include "EdDSA".
event_serialization	string	No	Serialization format for events. Defaults to "jws-flattened" if omitted.
Example:

{
  "spec_version": "sig/0.1",
  "issuer": "did:web:acme.example",
  "jwks_uri": "https://acme.example/.well-known/jwks.json",
  "events_uri": "https://acme.example/.well-known/sig-events.ndjson",
  "public_only": true,
  "algorithms_supported": ["EdDSA"]
}

CommonEventFields

Every event in the SIG protocol contains these fields in its payload.

Field	Type	Required	Description
spec_version	string	Yes	Must be "sig/0.1".
event_id	string	Yes	Unique identifier for this event. ULID or UUIDv7 recommended for natural ordering.
event_type	string	Yes	The event type: "relationship.upsert" or "relationship.revoke".
issuer	string	Yes	The issuer’s did:web identifier. Must match the DID in the metadata.
issued_at	string	Yes	Timestamp of when the event was created. RFC 3339 format, UTC (e.g. "2026-02-27T15:30:00Z").
sequence	integer	Yes	Monotonically increasing sequence number. Starts at 1 for the first event.
relationship_id	string	Yes	Identifier for the relationship this event pertains to. Stable across upserts and revocations of the same relationship.
subject	string	Yes	The subject’s did:web identifier (the entity the relationship is about).
visibility	string	Yes	Either "public" or "private". Determines whether this event is intended for public consumption.

JWS Flattened Envelope

Each event is wrapped in a JWS JSON Flattened Serialization envelope. This is the on-wire format: each line in the NDJSON feed is one of these objects.

Field	Type	Description
protected	string	Base64url-encoded protected header (JSON object).
payload	string	Base64url-encoded event payload (JSON object containing CommonEventFields + type-specific fields).
signature	string	Base64url-encoded Ed25519 signature computed over ASCII(protected).ASCII(payload).

Example:

{
  "protected": "eyJhbGciOiJFZERTQSIsImtpZCI6ImtleS0xIiwidHlwIjoib3JlLWV2ZW50K2p3cyJ9",
  "payload": "eyJzcGVjX3ZlcnNpb24iOiJvcmUvMC4xIiwiZXZlbnRfaWQiOiIwMUo...",
  "signature": "5Oj2eA3J7JzG..."
}

To verify, the consumer:

1. Base64url-decodes protected and payload.
2. Looks up the signing key using the kid from the decoded protected header.
3. Verifies the signature over the concatenation ASCII(protected) || '.' || ASCII(payload).

Protected Header

The decoded protected header contains:

Field	Type	Required	Description
alg	string	Yes	Signing algorithm. Must be "EdDSA".
kid	string	Yes	Key ID referencing a key in the issuer’s JWKS.
typ	string	Yes	Media type. Must be "sig-event+jws".

Example (decoded):

{
  "alg": "EdDSA",
  "kid": "key-1",
  "typ": "sig-event+jws"
}

DerivedRelationshipState

This is not a wire type. It is the computed state of a relationship after replaying the event log. Verifiers and consumers build this structure locally.

Field	Type	Description
issuer	string	The issuer’s did:web identifier.
relationship_id	string	The stable identifier for this relationship.
subject	string	The subject’s did:web identifier.
relationship_type	string	The type of relationship (e.g. "employee", "contractor").
roles	string[]	Current roles assigned to the subject.
valid_from	string | null	Start of the validity window (RFC 3339 UTC), or null if unbounded.
valid_until	string | null	End of the validity window (RFC 3339 UTC), or null if unbounded.
status	string	One of "active", "revoked", or "expired".
revoked_reason_code	string | null	If revoked, the reason code from the revocation event.
revoked_effective_at	string | null	If revoked, the effective timestamp of the revocation (RFC 3339 UTC).
last_sequence	integer	The sequence number of the most recent event affecting this relationship.

Status is derived as follows:

• active — The most recent event is a relationship.upsert and the current time is within the validity window (or the window is unbounded).
• expired — The most recent event is a relationship.upsert but the current time is past valid_until.
• revoked — The most recent event affecting this relationship is a relationship.revoke.

FeedState

The aggregate state derived from replaying an entire event feed.

Field	Type	Description
by_relationship_id	HashMap<string, DerivedRelationshipState>	Map from relationship_id to the derived state for that relationship.
last_sequence	integer	The highest sequence number seen in the feed.
Consumers build a FeedState by iterating through the NDJSON feed in order, verifying each event’s signature, and applying each event to the appropriate entry in by_relationship_id. After processing, the map contains the current state of every relationship the issuer has attested to.