Checked 2026-08-31

OKF v0.2 is the current specification.

Google Cloud published v0.2 on July 24, 2026. It keeps the v0.1 conformance floor and adds optional provenance, trust, lifecycle, and attestation fields. The project now has a dedicated canonical repository.

Read official specification Inspect specification history

Compatibility

The hard conformance rules did not grow.

A concept with only a valid type remains conformant. Optional metadata must not become a new rejection gate.

Concept files

Parseable frontmatter

Every non-reserved Markdown concept has YAML frontmatter and a non-empty string type.

Reserved files

Indexes and logs keep their roles

index.md lists directory contents. log.md groups updates under newest-first ISO date headings.

Consumers

Best-effort reading remains required

Unknown types, extension fields, missing optional metadata, broken links, and missing indexes must not make a bundle unusable.

Version 0.2

What the new fields let consumers decide.

Provenance

sources records what a concept derives from. Stable source IDs connect individual claims to Markdown footnotes.

Trust

generated records who wrote the current content. verified records independent checks and supports derived trust tiers.

Lifecycle

status distinguishes draft, stable, and deprecated concepts. stale_after creates a deterministic review deadline.

Attestation

Attested Computation records a sanctioned calculation, parameters, execution interface, and deterministic checking interface.

Replacements

Two v0.1 forms are now legacy fallbacks.

A v0.2 consumer may still read them. New producers should emit the v0.2 forms.

Legacy

`timestamp`

Use generated: { by, at } so the bundle records both producer identity and time.

Legacy

`# Citations`

Use frontmatter sources and keyed Markdown footnotes for claim-level attribution.

Open migration guide

Canonical home

The old repository copy is frozen.

The specification, reference agent, and sample bundles now live in GoogleCloudPlatform/open-knowledge-format. Google warns builders to stop using the older knowledge-catalog/okf snapshot because it is no longer maintained.

Open canonical repository Read v0.2 announcement

Use the current specification

Validate conformance separately from optional quality signals.

The site also compares the canonical file’s version and SHA-256 digest with this reviewed snapshot every day. A changed version or changed text fails the check for human review.

Validate bundle Explore implementations