diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..64a4b17
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,78 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1718318537,
+        "narHash": "sha256-4Zu0RYRcAY/VWuu6awwq4opuiD//ahpc2aFHg2CWqFY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e9ee548d90ff586a6471b4ae80ae9cfcbceb3420",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-old-hatch": {
+      "locked": {
+        "lastModified": 1702508050,
+        "narHash": "sha256-imn+/Rj+bqagOSm7GmRDbrqkxtc7QnjY3Cu85gv46BU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "fd04bea4cbf76f86f244b9e2549fca066db8ddff",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "fd04bea4cbf76f86f244b9e2549fca066db8ddff",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-old-hatch": "nixpkgs-old-hatch"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..3bd348a
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,45 @@
+{
+  description = "development environment for surplus";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    # https://github.com/NixOS/nixpkgs/issues/308121
+    nixpkgs-old-hatch.url = "github:NixOS/nixpkgs/fd04bea4cbf76f86f244b9e2549fca066db8ddff";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, nixpkgs-old-hatch, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        inherit (nixpkgs) lib;
+        pkgs = nixpkgs.legacyPackages.${system};
+        pkgs-old-hatch = nixpkgs-old-hatch.legacyPackages.${system};
+      in
+      {
+        devShells.default = pkgs.mkShellNoCC {
+          NIX_LD_LIBRARY_PATH = lib.makeLibraryPath [
+            pkgs.stdenv.cc.cc
+          ];
+          NIX_LD = lib.fileContents "${pkgs.stdenv.cc}/nix-support/dynamic-linker";
+          buildInputs =
+            [
+              # surplus
+              pkgs.python3
+              pkgs-old-hatch.hatch
+
+              # mkdocs-exporter
+              pkgs.stdenv.cc.cc.lib
+              pkgs.playwright
+            ];
+          shellHook = ''
+            export LD_LIBRARY_PATH=$NIX_LD_LIBRARY_PATH
+            export PLAYWRIGHT_BROWSERS_PATH=${pkgs.playwright-driver.browsers}
+            export PLAYWRIGHT_SKIP_VALIDATE_HOST_REQUIREMENTS=true
+            echo LD_LIBRARY_PATH=$LD_LIBRARY_PATH
+            echo PLAYWRIGHT_BROWSERS_PATH=$PLAYWRIGHT_BROWSERS_PATH
+            echo PLAYWRIGHT_SKIP_VALIDATE_HOST_REQUIREMENTS=$PLAYWRIGHT_SKIP_VALIDATE_HOST_REQUIREMENTS
+          '';
+        };
+      }
+    );
+}
diff --git a/src/spow-telegram-bridge/flake.lock b/src/spow-telegram-bridge/flake.lock
new file mode 100644
index 0000000..34f1f34
--- /dev/null
+++ b/src/spow-telegram-bridge/flake.lock
@@ -0,0 +1,175 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nix-github-actions": {
+      "inputs": {
+        "nixpkgs": [
+          "poetry2nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1703863825,
+        "narHash": "sha256-rXwqjtwiGKJheXB43ybM8NwWB8rO2dSRrEqes0S7F5Y=",
+        "owner": "nix-community",
+        "repo": "nix-github-actions",
+        "rev": "5163432afc817cf8bd1f031418d1869e4c9d5547",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nix-github-actions",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1718530797,
+        "narHash": "sha256-pup6cYwtgvzDpvpSCFh1TEUjw2zkNpk8iolbKnyFmmU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b60ebf54c15553b393d144357375ea956f89e9a9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "poetry2nix": {
+      "inputs": {
+        "flake-utils": "flake-utils_2",
+        "nix-github-actions": "nix-github-actions",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "systems": "systems_3",
+        "treefmt-nix": "treefmt-nix"
+      },
+      "locked": {
+        "lastModified": 1718656656,
+        "narHash": "sha256-/8pXTFOfb7+KrFi+g8G/dFehDkc96/O5eL8L+FjzG1w=",
+        "owner": "nix-community",
+        "repo": "poetry2nix",
+        "rev": "2c6d07717af20e45fa5b2c823729126be91a3cdf",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "poetry2nix",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs",
+        "poetry2nix": "poetry2nix"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_3": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "id": "systems",
+        "type": "indirect"
+      }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "poetry2nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1718522839,
+        "narHash": "sha256-ULzoKzEaBOiLRtjeY3YoGFJMwWSKRYOic6VNw2UyTls=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "68eb1dc333ce82d0ab0c0357363ea17c31ea1f81",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/src/spow-telegram-bridge/flake.nix b/src/spow-telegram-bridge/flake.nix
new file mode 100644
index 0000000..d63dc2a
--- /dev/null
+++ b/src/spow-telegram-bridge/flake.nix
@@ -0,0 +1,35 @@
+{
+  description = "development environment for surplus on wheels: Telegram Bridge";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    poetry2nix = {
+      url = "github:nix-community/poetry2nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, poetry2nix }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        inherit (poetry2nix.lib.mkPoetry2Nix { inherit pkgs; }) mkPoetryEnv;
+
+        poetryEnv = mkPoetryEnv {
+          python = pkgs.python311;
+          projectDir = self;
+          preferWheels = true;
+        };
+      in
+      {
+        # nix develop
+        devShells.default = pkgs.mkShellNoCC {
+          packages = [
+            pkgs.poetry
+            poetryEnv
+          ];
+        };
+      }
+    );
+}
diff --git a/src/spow-whatsapp-bridge/flake.lock b/src/spow-whatsapp-bridge/flake.lock
new file mode 100644
index 0000000..335c7ee
--- /dev/null
+++ b/src/spow-whatsapp-bridge/flake.lock
@@ -0,0 +1,85 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "gomod2nix": {
+      "inputs": {
+        "flake-utils": [
+          "flake-utils"
+        ],
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1717050755,
+        "narHash": "sha256-C9IEHABulv2zEDFA+Bf0E1nmfN4y6MIUe5eM2RCrDC0=",
+        "owner": "nix-community",
+        "repo": "gomod2nix",
+        "rev": "31b6d2e40b36456e792cd6cf50d5a8ddd2fa59a1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "gomod2nix",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1718530797,
+        "narHash": "sha256-pup6cYwtgvzDpvpSCFh1TEUjw2zkNpk8iolbKnyFmmU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b60ebf54c15553b393d144357375ea956f89e9a9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "gomod2nix": "gomod2nix",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/src/spow-whatsapp-bridge/flake.nix b/src/spow-whatsapp-bridge/flake.nix
new file mode 100644
index 0000000..ba5ef94
--- /dev/null
+++ b/src/spow-whatsapp-bridge/flake.nix
@@ -0,0 +1,115 @@
+{
+  description = "development environment for surplus on wheels: WhatsApp Bridge";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    gomod2nix = {
+      url = "github:nix-community/gomod2nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.flake-utils.follows = "flake-utils";
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, gomod2nix }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        bridge = {
+          name = "spow-whatsapp-bridge";
+          version = "2.2024.25";
+        };
+
+        pkgs = import nixpkgs {
+          system = system;
+          overlays = [
+            gomod2nix.overlays.default
+          ];
+          config = {
+            android_sdk.accept_license = true;
+            allowUnfree = true;
+          };
+        };
+
+        sdk = (pkgs.androidenv.composeAndroidPackages {
+          includeSources = false;
+          includeSystemImages = false;
+          includeEmulator = false;
+          includeNDK = true;
+          ndkVersions = ["26.3.11579264"];
+        }).androidsdk;
+
+        androidClang = (
+          "${sdk}/libexec/android-sdk/ndk-bundle/toolchains/llvm/prebuilt/"
+          +
+          (
+            {
+              "x86_64-darwin" = "darwin-x86_64";
+              "x86_64-linux" = "linux-x86_64";
+            }."${system}" or
+              (throw "the android ndk does not support your platform... (；′⌒`) (apple silicon users see https://github.com/android/ndk/issues/1299)")
+          )
+          +
+          "/bin/aarch64-linux-android30-clang"
+        );
+
+        bridgeBuildTermux = pkgs.buildGoApplication {
+          pname = bridge.name;
+          version = bridge.version;
+
+          go = pkgs.go_1_22;
+          src = ./.;
+          modules = ./gomod2nix.toml;
+
+          buildInputs = [ sdk ];
+          buildPhase = ''
+            runHook preBuild
+            mkdir -p $out/bin
+            CC="${androidClang}" CGO_ENABLED=1 GOOS=android GOARCH=arm64 go build -o $out/bin
+            runHook postBuild
+          '';
+        };
+
+        bridgeBuildNative = pkgs.buildGoApplication {
+          pname = bridge.name;
+          version = bridge.version;
+
+          go = pkgs.go_1_22;
+          src = ./.;
+          modules = ./gomod2nix.toml;
+        };
+      in
+      with pkgs; {
+        # nix develop
+        devShells.default = mkShell {
+          buildInputs = [
+            go
+            gomod2nix.packages.${system}.default
+          ];
+        };
+
+        # nix build .#termux
+        packages.termux = stdenvNoCC.mkDerivation {
+          pname = bridge.name;
+          version = bridge.version;
+          src = bridgeBuildTermux;
+
+          installPhase = ''
+            mkdir -p $out
+            cp $src/bin/$pname $out/$pname
+          '';
+        };
+
+        # nix build .#native
+        packages.native = stdenvNoCC.mkDerivation {
+          pname = bridge.name;
+          version = bridge.version;
+          src = bridgeBuildNative;
+
+          installPhase = ''
+            mkdir -p $out
+            cp $src/bin/$pname $out/$pname
+          '';
+        };
+      }
+    );
+}
diff --git a/src/spow-whatsapp-bridge/gomod2nix.toml b/src/spow-whatsapp-bridge/gomod2nix.toml
new file mode 100644
index 0000000..dd2506b
--- /dev/null
+++ b/src/spow-whatsapp-bridge/gomod2nix.toml
@@ -0,0 +1,54 @@
+schema = 3
+
+[mod]
+  [mod."filippo.io/edwards25519"]
+    version = "v1.1.0"
+    hash = "sha256-9ACANrgWZSd5HYPfDZHY8DVbPSC9LOMgy8deq3rDOoc="
+  [mod."github.com/google/uuid"]
+    version = "v1.6.0"
+    hash = "sha256-VWl9sqUzdOuhW0KzQlv0gwwUQClYkmZwSydHG2sALYw="
+  [mod."github.com/gorilla/websocket"]
+    version = "v1.5.3"
+    hash = "sha256-vTIGEFMEi+30ZdO6ffMNJ/kId6pZs5bbyqov8xe9BM0="
+  [mod."github.com/mattn/go-colorable"]
+    version = "v0.1.13"
+    hash = "sha256-qb3Qbo0CELGRIzvw7NVM1g/aayaz4Tguppk9MD2/OI8="
+  [mod."github.com/mattn/go-isatty"]
+    version = "v0.0.20"
+    hash = "sha256-qhw9hWtU5wnyFyuMbKx+7RB8ckQaFQ8D+8GKPkN3HHQ="
+  [mod."github.com/mattn/go-sqlite3"]
+    version = "v1.14.22"
+    hash = "sha256-CWF2Hjg43658NhaePWbGzS19gHJXjuTroG5c0W3hgYQ="
+  [mod."github.com/mdp/qrterminal/v3"]
+    version = "v3.2.0"
+    hash = "sha256-2ZcpLFu6P+a3qHH32uiFKUwzgza1NF0Bmayl41GQCEI="
+  [mod."github.com/rs/zerolog"]
+    version = "v1.33.0"
+    hash = "sha256-jT/Y/izhZiCdrDbC/ty83FGs8UQavTU+OW03O4vKFkY="
+  [mod."go.mau.fi/libsignal"]
+    version = "v0.1.0"
+    hash = "sha256-hSZQkw/0eV5Y0pj1N+idYuKb/jtiw/qTfaOGdYCXmn0="
+  [mod."go.mau.fi/util"]
+    version = "v0.4.2"
+    hash = "sha256-o/d7Wd+2byFxmVxjl5o/AAUO/2d12vzItq6H5yUtcow="
+  [mod."go.mau.fi/whatsmeow"]
+    version = "v0.0.0-20240603101645-64bc969fbe78"
+    hash = "sha256-MBDcxTHM+ZxxzIrendWWEhNdkPA7cLgkduC424+j+fU="
+  [mod."golang.org/x/crypto"]
+    version = "v0.24.0"
+    hash = "sha256-wpxJApwSmmn9meVdpFdOU0gzeJbIXcKuFfYUUVogSss="
+  [mod."golang.org/x/net"]
+    version = "v0.26.0"
+    hash = "sha256-WfY33QERNbcIiDkH3+p2XGrAVqvWBQfc8neUt6TH6dQ="
+  [mod."golang.org/x/sys"]
+    version = "v0.21.0"
+    hash = "sha256-gapzPWuEqY36V6W2YhIDYR49sEvjJRd7bSuf9K1f4JY="
+  [mod."golang.org/x/term"]
+    version = "v0.21.0"
+    hash = "sha256-zRm7uPBM1+TJkODYHkk/BtN3la5QAaSgslE2hSTm27Y="
+  [mod."google.golang.org/protobuf"]
+    version = "v1.34.2"
+    hash = "sha256-nMTlrDEE2dbpWz50eQMPBQXCyQh4IdjrTIccaU0F3m0="
+  [mod."rsc.io/qr"]
+    version = "v0.2.0"
+    hash = "sha256-I3fAJwwZhIrgBbCjWvIElAE9JqG2y59KRBc78EYi3RM="
diff --git a/src/surplus-on-wheels/flake.lock b/src/surplus-on-wheels/flake.lock
new file mode 100644
index 0000000..b8dd435
--- /dev/null
+++ b/src/surplus-on-wheels/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1718318537,
+        "narHash": "sha256-4Zu0RYRcAY/VWuu6awwq4opuiD//ahpc2aFHg2CWqFY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e9ee548d90ff586a6471b4ae80ae9cfcbceb3420",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/src/surplus-on-wheels/flake.nix b/src/surplus-on-wheels/flake.nix
new file mode 100644
index 0000000..505fd7d
--- /dev/null
+++ b/src/surplus-on-wheels/flake.nix
@@ -0,0 +1,20 @@
+{
+  description = "development environment for surplus on wheels";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      with pkgs; {
+        devShells.default = mkShellNoCC {
+          buildInputs = [ shfmt shellcheck ];
+        };
+      }
+    );
+}