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 597a6d0..36fc3a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,3 +30,7 @@ e2e/test-results/
 e2e/playwright-report/
 
 tmp/
+
+result
+
+.direnv
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..0b7e98c
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,77 @@
+{
+  "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1782949081,
+        "narHash": "sha256-vp6Y/Grm98ESt6ceOkWiHWyZRDV3J1RID4w+6NWK9yA=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "17c9d6cdfc60c64f4ee8d306f9bc0b4ccb51481e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "haskell-flake": {
+      "locked": {
+        "lastModified": 1785340889,
+        "narHash": "sha256-W3VSD3CKNF/WSLwS+A4ru1pXb2J8GN1xi4MjWacpwJA=",
+        "owner": "srid",
+        "repo": "haskell-flake",
+        "rev": "ec69967e95d7e93b58d9f7cdd384432cb42d37ee",
+        "type": "github"
+      },
+      "original": {
+        "owner": "srid",
+        "repo": "haskell-flake",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1785301185,
+        "narHash": "sha256-eoS3KQTO0aPWXZvIaRbRAzSSHW3l5wdMFXtT1ISfoKA=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "9bc02893134c733dd85de46ee4fb2fac696b5529",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "lastModified": 1782614948,
+        "narHash": "sha256-ePjCwr1sNm9NYUqywL7QfK3JnlS015msC+eBu2zKlp8=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "db3f255737b94216eb71cce308e2912cf6bc2d7c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "haskell-flake": "haskell-flake",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..b3fa8cb
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,62 @@
+{
+  description = "Datastar Haskell SDK";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+    haskell-flake.url = "github:srid/haskell-flake";
+  };
+
+  outputs =
+    inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      imports = [ inputs.haskell-flake.flakeModule ];
+
+      perSystem =
+        { self', pkgs, ... }:
+        {
+          haskellProjects.default = {
+            packages = {
+              # `haskell-flake` ignores `source-repository-package` defined in `cabal.project`.
+              # That's why `hs-zstd` needs to be pinned here. All because of https://github.com/starfederation/datastar-haskell/issues/3
+              # Note: `fetchSubmodules` is needed -> `zstd.cabal` provides `zstd` in a submodule.
+              zstd.source = pkgs.fetchgit {
+                url = "https://github.com/luispedro/hs-zstd";
+                rev = "59c0d21ab65a6296e06446c8368d78b9b4c7e64d";
+                fetchSubmodules = true;
+                hash = "sha256-jGRiFZf5M/mNOXeWjtEkDQOZEi0Vry+pYRLutJkHuT0=";
+              };
+
+              # Note: `WAI.hs` needs `hAcceptEncoding` (from `Network.HTTP.Types`),
+              # which is available in `http-types` >= `v0.12.5` only.
+              # Side note: nixpkgs pins to `0.12.4` only. `source = "0.12.5"` does not work either (not available in frozen Hackage index).
+              http-types.source = pkgs.fetchzip {
+                url = "https://hackage.haskell.org/package/http-types-0.12.5/http-types-0.12.5.tar.gz";
+                hash = "sha256-Y1/wrRFPIVxgTGWgPboRDUht+fzvl3e1jazj+G1pTw0=";
+              };
+            };
+
+            devShell.tools = hp: {
+              # cabal-install, haskell-language-server, ghcid and hlint are defaults.
+              inherit (hp) fourmolu cabal-fmt;
+              inherit (pkgs) pkg-config nixfmt nixd;
+            };
+          };
+
+          formatter = pkgs.nixfmt;
+
+          packages.default = self'.packages.datastar-hs;
+
+          # `nix flake check` builds / tests everything (similar to `cabal build all && cabal test all`)
+          checks.all = pkgs.linkFarmFromDrvs "datastar-hs-all" (
+            builtins.attrValues (removeAttrs self'.packages [ "default" ])
+          );
+        };
+    };
+}