diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.gitignore b/.gitignore
index 76741c2..af1ac9c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,5 @@
 # These are backup files generated by rustfmt
 **/*.rs.bk
 
+# Ignore direnv directory
+.direnv/
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..25b0fc5
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1777578337,
+        "narHash": "sha256-Ad49moKWeXtKBJNy2ebiTQUEgdLyvGmTeykAQ9xM+Z4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "15f4ee454b1dce334612fa6843b3e05cf546efab",
+        "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..8e91567
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,44 @@
+{
+  description = "Development environment for commit-email";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs systems;
+    in
+    {
+      devShells = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+        in
+        {
+          default = pkgs.mkShell {
+            packages = with pkgs; [
+              rustc
+              rustfmt
+              cargo
+              clippy
+
+              # Required by openssl-sys crate
+              pkg-config
+              openssl
+
+              nil
+              nixfmt
+            ];
+          };
+        }
+      );
+    };
+}