Data is queried, not merged
Kinds, instances and typed fields are data. Content in many files never overwrites itself.
yen
Nix configurations you can ask questions about,
and prove things about, before you deploy.
yen is a query language for Nix configurations. You write plain Nix data and behavior. yen answers queries on it: the NixOS, nix-darwin and home-manager systems to build, the errors, the graph of who gives what to whom, and whether your rules hold.
Behavior lands where you say
An aspect is active where its predicate holds. Its elements go to the nearest scope that collects them.
Questions have answers
Graphs, Datalog with a well-founded semantics, and µKanren with constraints. All pure Nix.
Safe for agents
A change is staged, checked against your rules across machines, and refused with its reason. An MCP server answers agents.