Flake for declarative installation through nix

flake.nix

@@ -0,0 +1,48 @@
+{
+  description = "Cosma — a document graph visualization tool";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f system nixpkgs.legacyPackages.${system});
+    in
+    {
+      packages = forAllSystems (
+        system: pkgs: {
+          default = pkgs.buildNpmPackage {
+            pname = "cosma";
+            version = "2.6.1";
+            src = ./.;
+            nodejs = pkgs.nodejs_22;
+
+            # Use package-lock.json instead of flake.lock for dependency locking.
+            npmDeps = pkgs.importNpmLock { npmRoot = ./.; };
+            npmConfigHook = pkgs.importNpmLock.npmConfigHook;
+
+            # Skip install lifecycle scripts during `npm ci`.
+            npmFlags = [ "--ignore-scripts" ];
+
+            npmBuildScript = "prepare";
+
+            meta = {
+              description = "Document graph visualization tool";
+              homepage = "https://cosma.arthurperret.fr/";
+              license = with pkgs.lib.licenses; [
+                gpl3Plus
+                cecill21
+              ];
+              mainProgram = "cosma";
+            };
+          };
+        }
+      );
+    };
+}