Your first flake Adds a `flake.nix` so the project can be built and checked with Nix (and run on NixCI). It provides: * `packages.default` — builds the dspy wheel (`python -m build`). * `devShells.default` — python + uv + ruff + pre-commit development environment. * `checks` — the package, the devShell, and a ruff lint gate mirroring the existing CI. `nix flake check` builds every package and devShell. Passing CI: https://staging.nix-ci.com/gh:NorfairKing:dspy/your-first-flake/cb8190b66789cb31dcb8babd71f9006186d44c65