SignalQL v0.5 — object model

Status: Draft with reference implementation. Part of the v0.5 specification. See also provenance and context bundles.

Object

An object is any stable, addressable piece of information: a document, file, message, source file, video, image, dataset, conversation, AI output, meeting, or database record.

An object has an identity that is independent of where it is stored:

object://01JZX8…

A path such as /projects/signalql/spec.md is metadata or a view. It MUST NOT define identity: moving or renaming an object does not change its address.

Object vs entity

	Is	Example
OBJECT	a stored or addressable information artifact	q3-report.pdf
ENTITY	a semantic thing the information is about	Acme Corp, Project Phoenix

Objects and entities are separate node classes in one graph. They are linked by ordinary edges (for example an object mentions an entity), so the v0.4 graph operators (MATCH, FIND … CONNECTED TO, PATH, TRACE, CONTEXT FOR) work across both without change. Only objects have revisions, representations, and derivations. Object ids and entity ids share one namespace.

Revision

A revision is one state of an object.

A revision changes state. It does not change identity.

object://abc@16 and object://abc@17 are two states of one object. Revisions are numbered from 1 and never renumbered.

Revision selection, with T the AS OF time (or unbounded when absent):

1. @n selects exactly revision n. If it does not exist, or was created after T, the result is empty.
2. Without @n, the selected revision is the greatest revision created at or before T. If there is none, the object did not exist at T.
3. When both are given, @n selects the revision and AS OF bounds everything else that is read.

superseded is a property of a revision (a later revision exists as of T). It is not a judgment about validity.

Origin, trust, validation, and roles describe a state of the object, so they are recorded per revision.

Representation

One object may exist in several forms:

OBJECT meeting_123
├── original-video
├── transcript
├── summary
├── decisions
└── embeddings

These are representations of one object, not unrelated objects. A representation belongs to a specific revision, has a name unique within that revision, a media type, and optionally a token estimate with the name of the estimator that produced it.

A summary can be modelled either way. The rule: it is a representation unless it needs its own identity, history, or trust — in which case it is its own object linked by a derivation.

Logical sources

The reference compiler binds four logical sources through the source map. A deployment maps each to a physical table or view.

Source	Columns
objects	object_id, type, title, project, metadata (json), created_at, tombstoned_at
object_revisions	object_id, rev, created_at, origin, trust, validation, roles (array), content_hash
object_representations	object_id, rev, name, media_type, token_estimate, estimator, roles (array), content, content_ref, content_hash
object_derivations	from_object, from_rev, relation, to_object, to_rev, created_at, metadata (json)

project is an opaque partition label; the language attaches no meaning to it. tombstoned_at records that an object was withdrawn; it is reported only when it falls at or before AS OF.

Graph projection

A v0.5 store MUST expose objects to the v0.4 graph sources:

• each object revision as an entities row (entity_id = object_id, kind = type, properties = metadata + title + project + revision, updated_at = revision created_at);
• each derivation as an edges row (from_entity = from_object, relationship = relation, to_entity = to_object, observed_at = created_at).

This is a binding requirement on the store, not a change to the v0.4 compiler.

As in v0.4, a graph query without AS OF sees every stored version of a node, so an object with several revisions matches once per revision. Graph queries over objects SHOULD carry AS OF, which selects one revision per object.

Result shapes

Statement	Columns
GET OBJECT	object_id, type, title, project, revision, latest_revision, revised_at, origin, trust, validation, state, roles, metadata, created_at, tombstoned_at
SHOW REVISIONS	object_id, revision, created_at, origin, trust, validation, roles, content_hash, superseded — newest first
SHOW REPRESENTATIONS	object_id, revision, name, media_type, token_estimate, estimator, roles — ordered by name
GET REPRESENTATION	the above plus content, content_ref, content_hash

state is the revision's dependency state (see provenance). Rows are returned in the v0.3 result envelope. String ordering is by code unit (COLLATE "C" in SQL) so results do not depend on locale.

Limitations

• Trust metadata is not bitemporal. AS OF reproduces which revision was current, not what a revision's trust was believed to be at that time.
• Reading a representation's content is subject to the deployment's permission layer; the language does not define access control.