Hyalo is a high-performance CLI tool designed to query, manage, and bulk-edit Markdown collections that use YAML frontmatter, such as Obsidian vaults, Zettelkastens, and static documentation sites. Hyalo natively understands Markdown structures to offer advanced filtering, bulk metadata mutations, and smart link refactoring across thousands of files in milliseconds. With native JSON output, built-in AI agent integrations, and robust dry-run safety features, Hyalo provides a fast, scriptable solution for maintaining and automating complex knowledge bases.