Nix flake for btca (Better Context) - a CLI tool that helps AI agents get up-to-date context on libraries/technologies by searching actual source code.

Run btca directly without installation:

nix run github:dominicnunez/btca-nix

This package includes sensible defaults so btca works out of the box:

Install btca to your user profile:

nix profile add github:dominicnunez/btca-nix

Add btca to your flake-based configuration:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    btca-nix.url = "github:dominicnunez/btca-nix";
  };

  outputs = { self, nixpkgs, btca-nix, ... }: {
    # Option 1: Use the overlay
    nixosConfigurations.myhost = nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      modules = [
        {
          nixpkgs.overlays = [ btca-nix.overlays.default ];
          environment.systemPackages = [ pkgs.btca ];
        }
      ];
    };

    # Option 2: Use the package directly
    # btca-nix.packages.x86_64-linux.btca
  };
}

btca can take Nix-provided defaults via the userSettings argument, which are merged into the runtime config at ~/.config/btca/btca.config.jsonc.

{
  outputs = { self, nixpkgs, btca-nix, ... }: {
    packages.x86_64-linux.btca = btca-nix.packages.x86_64-linux.btca.override {
      userSettings = {
        provider = "openai";
        model = "gpt-4.1-mini";
      };
    };
  };
}

Merge behavior:

• On first run, btca writes the Nix defaults (including the $schema field) to ~/.config/btca/btca.config.jsonc.
• On subsequent runs, Nix defaults are merged into the existing config, but user edits take precedence and user-only keys are preserved.
• The config is only rewritten when the Nix-provided settings change.

This flake uses Garnix for CI and binary caching. The nixConfig in flake.nix automatically configures the cache, so pre-built binaries are fetched without any manual setup.

If prompted to allow configuration from the flake, answer yes or add accept-flake-config = true to your Nix configuration.

btca (Better Context) helps AI agents get up-to-date context on libraries and technologies by searching actual source code. Learn more at btca.dev.