OKF (Open Knowledge Format) is portable knowledge: Markdown files with YAML frontmatter that both humans and agents read from one source. This gem is the Ruby-native way to work with it. Its companion agent skill authors and curates a bundle; the `okf` command-line tool validates the result for v0.1 (§9) conformance, lints its curation quality, and serves it as an interactive graph (a mountable Rack app). The same validate, lint, and graph run in-process through a library API (OKF::Bundle and friends).