diff --git a/flake.lock b/flake.lock
index ee81d0a..a4fadf6 100644
--- a/flake.lock
+++ b/flake.lock
@@ -16,9 +16,44 @@
         "type": "github"
       }
     },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1770107345,
+        "narHash": "sha256-tbS0Ebx2PiA1FRW8mt8oejR0qMXmziJmPaU1d4kYY9g=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "4533d9293756b63904b7238acb84ac8fe4c8c2c4",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "treefmt-nix": "treefmt-nix"
+      }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1773297127,
+        "narHash": "sha256-6E/yhXP7Oy/NbXtf1ktzmU8SdVqJQ09HC/48ebEGBpk=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "71b125cd05fbfd78cab3e070b73544abe24c5016",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index 8c23277..5f0c6ba 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,9 +1,15 @@
 {
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    treefmt-nix.url = "github:numtide/treefmt-nix";
   };
 
-  outputs = {nixpkgs, ...}: let
+  outputs = {
+    self,
+    nixpkgs,
+    treefmt-nix,
+    ...
+  }: let
     forSystems = fn:
       nixpkgs.lib.genAttrs [
         "aarch64-linux"
@@ -12,10 +18,16 @@
         "x86_64-linux"
       ] (system: fn nixpkgs.legacyPackages.${system});
     defaultForSystems = fn: forSystems (pkgs: {default = fn pkgs;});
+    treefmtEval = forSystems (pkgs: treefmt-nix.lib.evalModule pkgs ./treefmt.nix);
   in {
     devShells = defaultForSystems (pkgs:
       pkgs.mkShell {
         nativeBuildInputs = with pkgs; [elixir erlang];
       });
+
+    formatter = forSystems (pkgs: treefmtEval.${pkgs.stdenv.hostPlatform.system}.config.build.wrapper);
+    checks = forSystems (pkgs: {
+      formatting = treefmtEval.${pkgs.stdenv.hostPlatform.system}.config.build.check self;
+    });
   };
 }
diff --git a/treefmt.nix b/treefmt.nix
new file mode 100644
index 0000000..4740375
--- /dev/null
+++ b/treefmt.nix
@@ -0,0 +1,8 @@
+{...}: {
+  projectRootFile = "flake.nix";
+  programs.alejandra.enable = true;
+  programs.mix-format.enable = true;
+  programs.prettier.enable = true;
+
+  settings.formatter.prettier.proseWrap = "always";
+}