diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..13ef078
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1783224372,
+        "narHash": "sha256-8i/87eeoqiGE4yOTjwSA3Eh/ziJRQEmd/unYU+K27sk=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d407951447dcd00442e97087bf374aad70c04cea",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..aedbe6a
--- /dev/null
+++ b/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";
+            };
+          };
+        }
+      );
+    };
+}