diff --git a/.bazelignore b/.bazelignore
new file mode 100644
index 0000000..92b2793
--- /dev/null
+++ b/.bazelignore
@@ -0,0 +1 @@
+.direnv
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c4b1ce9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,8 @@
+# Misc
+/.direnv
+/.envrc
+
+# Bazel
+bazel-*
+MODULE.bazel.lock
+
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..8407bf9
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,69 @@
+{
+  description = "fpga-assembler";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/2c8d3f48d33929642c1c12cd243df4cc7d2ce434";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }@inputs:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+        common = with pkgs; {
+          bazel = bazel_7;
+          jdk = jdk;
+        };
+      in
+      {
+        devShells.default =
+          let
+            # There is too much volatility between even micro-versions of
+            # newer clang-format. Use slightly older version for now.
+            clang_for_formatting = pkgs.llvmPackages_17.clang-tools;
+
+            # clang tidy: use latest.
+            clang_for_tidy = pkgs.llvmPackages_18.clang-tools;
+          in
+          with pkgs;
+          pkgs.mkShell {
+            packages = with pkgs; [
+              git
+              common.bazel
+              common.jdk
+              bash
+              gdb
+
+              # For clang-tidy and clang-format.
+              clang_for_formatting
+              clang_for_tidy
+
+              # For buildifier, buildozer.
+              bazel-buildtools
+              bant
+
+              # Profiling and sanitizers.
+              linuxPackages_latest.perf
+              pprof
+              perf_data_converter
+              valgrind
+            ];
+
+            CLANG_TIDY = "${clang_for_tidy}/bin/clang-tidy";
+            CLANG_FORMAT = "${clang_for_formatting}/bin/clang-format";
+
+            shellHook = ''
+              exec bash
+            '';
+          };
+      }
+    );
+}