What is OKF, the Open Knowledge Format?

By Ricardo Cardona · September 21, 2026

OKF, the Open Knowledge Format, is an open specification from Google Cloud for writing knowledge down as a folder of markdown files that people can read and AI agents can use. Each file describes one thing, opens with a short block of fields, and links to other files with ordinary markdown links. The only required field is type.

Google Cloud published it in June 2026. It’s vendor-neutral: you don’t need a Google account, a runtime or an SDK to write it or to read it. This guide describes version 0.2.

What an OKF file looks like

Each file is one concept: a client, a metric, a process, a decision. It starts with YAML frontmatter and continues as plain markdown:

---
type: Client
title: Wheel & Whisker Daycare
description: Partner venue on a monthly statement, paid net 30.
tags: [Client, Business]
---

A partner venue since March, billed on the monthly statement.
See the [March statement](/money/statements/2026-03.md).

A folder of files like this is an OKF bundle. You can keep it in git, zip it or sync it. Nothing else is needed.

The fields

Required: type. A short string that says what the concept is. There is no central list. You choose descriptive values, and tools are expected to cope with types they don’t know.
Recommended: title, description (one sentence), resource (a URL for the real thing the file describes) and tags (a list).
Optional families for when the knowledge needs to carry its own credibility:
- Where it came from (sources): the artifacts a file is based on.
- Who wrote it and who checked it (generated, verified): an agent, a person or a process, with a date. The spec writes a person as human: followed by an id, so a tool can tell human-reviewed knowledge from machine-written knowledge.
- How current it is (status: draft, stable or deprecated, and stale_after): so an agent knows when to stop trusting a file.

Links, indexes and logs

Files point to each other with standard markdown links. The spec recommends links that start from the top of the bundle, like /clients/wheel-and-whisker.md, because they keep working when files move. A link says two things are related. The words around it say how. Broken links are tolerated rather than fatal.

Two file names are reserved:

index.md lists what a folder holds, so an agent can read the map before the details.
log.md records changes, grouped by date, newest first.

What OKF is not

The spec is deliberately small. It doesn’t define a fixed list of types, storage or serving infrastructure, or a replacement for formats like OpenAPI. It isn’t a search trick either: it’s written for agents that need curated context, not for ranking pages. Its stated aims are knowledge that is readable without tooling, parseable without special SDKs, diffable in version control and portable across tools.

Why it matters for a business of one

If you already keep notes in markdown, you’re most of the way there. Add a type to every file and a one-line description, and any OKF-aware agent can tell a client from an invoice without reading either one first.

The payoff is independence. Your business stops being context locked inside one AI product and becomes a folder that any agent can read today, and whichever one you switch to next year can read tomorrow.

How Oknola uses OKF

OKF standardizes the file. Indexed Brain, our architecture, organizes the files. Oknola keeps both true while you work: every file it writes carries its type, tags and description, so the folder stays legible to you and to any agent you point at it. It’s also where Oknola gets its name. More in how it works, and what is available today is on the roadmap.

Questions people ask

Is OKF only for Google Cloud?

No. Google Cloud wrote the spec, but it’s vendor-neutral. Any tool can produce OKF files and any agent can read them.

Do I need special tools to write OKF?

No. A text editor is enough. The spec’s own test is that you can read a bundle without any tooling.

Is OKF the same as llms.txt?

No. llms.txt is a single summary file a website publishes for AI tools. OKF is a format for a whole folder of knowledge, one concept per file.

Can I use OKF with Obsidian?

Yes. Obsidian notes are markdown files with YAML properties. Give every note a type and you’re writing OKF.