feat: make Claude Code, Codex, Gemini CLI and Goose automatically available in the Nix env

Author: zah

flake.lock

@@ -1,20 +1,34 @@
 {
   description = "agents-workflow";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    codex.url = "github:openai/codex";
+    codex.inputs.nixpkgs.follows = "nixpkgs";
+  };
 
   outputs = {
     self,
     nixpkgs,
+    codex,
   }: let
     systems = ["x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin"];
     forAllSystems = nixpkgs.lib.genAttrs systems;
   in {
     packages = forAllSystems (
       system: let
-        pkgs = import nixpkgs {inherit system;};
+        pkgs = import nixpkgs {
+          inherit system;
+          config.allowUnfree = true; # Allow unfree packages like claude-code
+        };
         agent-task-script = pkgs.writeShellScriptBin "agent-task" ''
-          PATH=${pkgs.lib.makeBinPath [ pkgs.ruby pkgs.codex pkgs.goose ]}:$PATH
+          PATH=${pkgs.lib.makeBinPath [
+            pkgs.ruby
+            pkgs.goose-cli
+            pkgs.claude-code
+            pkgs.gemini-cli
+            codex.packages.${system}.codex-rs
+          ]}:$PATH
           exec ruby ${./bin/agent-task} "$@"
         '';
         get-task = pkgs.writeShellScriptBin "get-task" ''
@@ -25,7 +39,7 @@
         '';
         agent-utils = pkgs.symlinkJoin {
           name = "agent-utils";
-          paths = [ get-task start-work ];
+          paths = [get-task start-work];
         };
       in {
         agent-task = agent-task-script;
@@ -42,7 +56,10 @@
     });
 
     devShells = forAllSystems (system: let
-      pkgs = import nixpkgs {inherit system;};
+      pkgs = import nixpkgs {
+        inherit system;
+        config.allowUnfree = true; # Allow unfree packages like claude-code
+      };
     in {
       default = pkgs.mkShell {
         buildInputs = [
@@ -53,7 +70,17 @@
           pkgs.git
           pkgs.fossil
           pkgs.mercurial
+
+          # AI Coding Assistants (latest versions from nixpkgs-unstable)
+          pkgs.goose-cli # Goose AI coding assistant
+          pkgs.claude-code # Claude Code - agentic coding tool
+          pkgs.gemini-cli # Gemini CLI
+          codex.packages.${system}.codex-rs # OpenAI Codex CLI (native Rust implementation)
         ];
+
+        shellHook = ''
+          echo "Agent workflow development environment loaded"
+        '';
       };
     });
   };