feat(nix): add package validation and pinned lock regeneration

.github/workflows/ci.yml

@@ -38,14 +38,6 @@ jobs:
       - name: Install dependencies
         run: bun install --frozen-lockfile
 
-      - name: Verify Nix lockfile is up to date
-        run: |
-          bun run nix:update-lock
-          if ! git diff --exit-code nix/bun.lock.nix; then
-            echo "::error::Nix lockfile is out of date. Please run 'bun run nix:update-lock' and commit the changes to nix/bun.lock.nix."
-            exit 1
-          fi
-
       - name: Format check
         run: bun run format:check
 

.github/workflows/nix.yml

@@ -0,0 +1,59 @@
+name: Nix
+
+on:
+  pull_request:
+    paths-ignore:
+      - "**/*.md"
+      - "docs/**"
+      - "assets/**"
+      - "LICENSE"
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - "**/*.md"
+      - "docs/**"
+      - "assets/**"
+      - "LICENSE"
+
+concurrency:
+  group: nix-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  package:
+    name: Package
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Install Nix
+        uses: cachix/install-nix-action@8aa03977d8d733052d78f4e008a241fd1dbf36b3 # v31.10.6
+        with:
+          extra_nix_config: |
+            extra-trusted-substituters = https://nix-community.cachix.org
+            extra-trusted-public-keys = nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=
+
+      - name: Verify Nix dependency lockfile
+        run: |
+          nix run .#update-bun-lock
+          if ! git diff --exit-code nix/bun.lock.nix; then
+            echo "::error::Nix lockfile is out of date. Please run 'bun run nix:update-lock' and commit the changes to nix/bun.lock.nix."
+            exit 1
+          fi
+
+      - name: Check flake outputs
+        run: nix flake check --print-build-logs
+
+      - name: Evaluate all supported systems
+        run: nix flake check --all-systems --no-build
+
+      - name: Build Hunk package
+        run: nix build .#default --print-build-logs
+
+      - name: Smoke test Nix package
+        run: |
+          ./result/bin/hunk --version
+          skill_path="$(./result/bin/hunk skill path)"
+          test -f "$skill_path"

.github/workflows/pr-ci.yml

@@ -81,14 +81,6 @@ jobs:
       - name: Install dependencies
         run: bun install --frozen-lockfile
 
-      - name: Verify Nix lockfile is up to date
-        run: |
-          bun run nix:update-lock
-          if ! git diff --exit-code nix/bun.lock.nix; then
-            echo "::error::Nix lockfile is out of date. Please run 'bun run nix:update-lock' and commit the changes to nix/bun.lock.nix."
-            exit 1
-          fi
-
       - name: Format check
         run: bun run format:check
 

CHANGELOG.md

@@ -7,6 +7,7 @@ All notable user-visible changes to Hunk are documented in this file.
 ### Added
 
 - Added Windows x64 prebuilt artifact publishing to the release workflow.
+- Added Nix flake app outputs for `nix run` and a named `hunk` package output.
 
 ### Changed
 

CONTRIBUTING.md

@@ -87,6 +87,24 @@ bun run check:prebuilt-pack
 bun run publish:prebuilt:npm -- --dry-run
 ```
 
+## Updating dependencies
+
+After changing JavaScript or Bun dependencies, regenerate the Nix dependency lockfile so CI stays green:
+
+```bash
+bun install
+bun run nix:update-lock
+git add bun.lock nix/bun.lock.nix package.json
+```
+
+The `nix:update-lock` script requires a one-time [Nix install](https://nixos.org/download/):
+
+```bash
+curl -L https://nixos.org/nix/install | sh
+```
+
+If you don't have Nix installed, CI will catch the drift and a maintainer can push the regenerated lockfile as a follow-up commit.
+
 ## Validation expectations
 
 - Rendering changes: run `bun run typecheck`, `bun test`, `bun run test:tty-smoke`, and do one real TTY smoke run on an actual diff.

flake.nix

@@ -27,28 +27,48 @@
       "aarch64-darwin"
     ];
     forAllSystems = lib.genAttrs supportedSystems;
-  in {
-    packages = forAllSystems (
+    perSystem = forAllSystems (
       system: let
         pkgs = import nixpkgs {
           inherit system;
         };
-      in {
-        default = pkgs.callPackage ./nix/package.nix {
+        hunk = pkgs.callPackage ./nix/package.nix {
           bun2nix = bun2nix.packages.${system}.default;
         };
-      }
-    );
-
-    devShells = forAllSystems (
-      system: let
-        pkgs = import nixpkgs {
-          inherit system;
-        };
+        updateBunLock = pkgs.writeShellScriptBin "hunk-update-bun-lock" ''
+          set -euo pipefail
+          ${bun2nix.packages.${system}.default}/bin/bun2nix -o nix/bun.lock.nix -c ../ "$@"
+          if [ -s nix/bun.lock.nix ] && [ "$(${pkgs.coreutils}/bin/tail -c 1 nix/bun.lock.nix)" != "" ]; then
+            printf '\n' >> nix/bun.lock.nix
+          fi
+        '';
       in {
-        default = pkgs.callPackage ./nix/devShell.nix {};
+        packages = {
+          inherit hunk;
+          default = hunk;
+        };
+        apps = {
+          default = {
+            type = "app";
+            program = "${hunk}/bin/hunk";
+            meta.description = "Run Hunk";
+          };
+          update-bun-lock = {
+            type = "app";
+            program = "${updateBunLock}/bin/hunk-update-bun-lock";
+            meta.description = "Regenerate nix/bun.lock.nix with the flake-pinned bun2nix";
+          };
+        };
+        devShells = {
+          default = pkgs.callPackage ./nix/devShell.nix {};
+        };
       }
     );
+    systemOutput = name: lib.mapAttrs (_: value: value.${name}) perSystem;
+  in {
+    packages = systemOutput "packages";
+    apps = systemOutput "apps";
+    devShells = systemOutput "devShells";
 
     homeManagerModules = {
       hunk = import ./nix/home-manager.nix;

nix/README.md

@@ -22,7 +22,7 @@ Nix users can install Hunk from source instead of using npm.
 ```nix
 {
   environment.systemPackages = [
-    inputs.hunk.packages.${pkgs.stdenv.hostPlatform.system}.default
+    inputs.hunk.packages.${pkgs.stdenv.hostPlatform.system}.hunk
   ];
 }
 ```
@@ -32,7 +32,7 @@ Or in Home Manager `home.packages`:
 ```nix
 {
   home.packages = [
-    inputs.hunk.packages.${pkgs.stdenv.hostPlatform.system}.default
+    inputs.hunk.packages.${pkgs.stdenv.hostPlatform.system}.hunk
   ];
 }
 ```
@@ -63,6 +63,14 @@ Hunk provides a Home Manager module to manage both the package and its configura
 
 `enableGitIntegration` writes to Home Manager's Git configuration, so it requires Home Manager's Git module to be enabled with `programs.git.enable = true;`.
 
+## Running from a flake
+
+Run Hunk directly with Nix:
+
+```bash
+nix run github:modem-dev/hunk -- --help
+```
+
 ## Updating Hunk
 
 Flake users update Hunk by updating their own pinned `flake.lock` input:
@@ -73,8 +81,13 @@ nix flake lock --update-input hunk
 
 ## Building using Nix
 
-Simply run `nix build .#packages.{YOUR_SYSTEM}.default` where YOUR_SYSTEM is one of `x86_64-linux`, `x86_64-darwin`, `aarch64-linux` or `aarch64-darwin`. The resulting
-Hunk binary will be `./result/bin/hunk`.
+Run `nix build` to build the default package for the current system. The resulting Hunk binary will be `./result/bin/hunk`.
+
+You can also build the named package explicitly:
+
+```bash
+nix build .#hunk
+```
 
 ## Maintainer dependency updates
 
@@ -83,3 +96,5 @@ When JavaScript or Bun dependencies change, regenerate the Nix dependency lockfi
 ```bash
 bun run nix:update-lock
 ```
+
+This script requires Nix and runs the flake-pinned `bun2nix` version from `flake.lock`.

package.json

@@ -71,7 +71,7 @@
     "bench:highlight-prefetch": "bun run benchmarks/highlight-prefetch.ts",
     "bench:large-stream": "bun run benchmarks/large-stream.ts",
     "bench:large-stream-profile": "bun run benchmarks/large-stream-profile.ts",
-    "nix:update-lock": "bunx bun2nix -o nix/bun.lock.nix -c ../"
+    "nix:update-lock": "nix run .#update-bun-lock"
   },
   "dependencies": {
     "@pierre/diffs": "^1.1.19",
@@ -87,7 +87,7 @@
     "@hunk/session-broker-node": "workspace:*",
     "@opentui/core": "^0.1.88",
     "@opentui/react": "^0.1.88",
-    "@types/bun": "latest",
+    "@types/bun": "1.3.10",
     "@types/react": "^19.2.14",
     "@types/ws": "^8.18.1",
     "lint-staged": "^16.4.0",