Your repositories don't live in a vacuum. Ownership, tiers, compliance status, on-call, and cost data usually already exist in your internal platform, service catalog, or CMDB, but getting that context into GitHub has meant copying it in and keeping it in sync.

This session introduces external custom properties and why they matter. We'll cover what they are, how they differ from standard custom properties, and the core value: instead of duplicating data, you reflect metadata you already own into GitHub as read-only properties, with your system staying the single source of truth. No two-way sync, no drift, no fighting over who owns the value, and it works everywhere custom properties already do: filters, selectors, and rulesets. To show it in practice, we'll walk through Port as a reference example, syncing real metadata into GitHub and putting it to work across repositories.

You'll leave understanding when to reach for external custom properties, the ownership and sync model behind them, and how partners like Port build on top of them.