Kaelio

Kaelio is a San Francisco startup (Y Combinator, 2025) building the open-source context layer that makes AI data agents reliable. Its core project, ktx, auto-builds a governed layer of business knowledge and executable metric definitions from a company's data stack - Markdown wiki pages plus YAML that declares tables, joins, grain, measures and filters. Instead of an agent writing raw SQL that looks right but returns wrong numbers, it asks ktx for a metric and ktx plans the joins and compiles warehouse SQL. Kaelio ships ktx (Apache 2.0), a hosted ktx Cloud with governance and observability, and a managed Data Agent that answers questions in Slack, web and email with source-backed results.