diff --git a/Gemfile b/Gemfile
deleted file mode 100644
index e5212d2..0000000
--- a/Gemfile
+++ /dev/null
@@ -1,11 +0,0 @@
-source "https://rubygems.org"
-
-gem "base64"
-gem "erb"
-gem "json"
-gem "net-http"
-gem "sequel"
-gem "sinatra"
-gem "uri"
-gem "xxhash"
-gem "zlib"
diff --git a/Gemfile.lock b/Gemfile.lock
deleted file mode 100644
index 626f954..0000000
--- a/Gemfile.lock
+++ /dev/null
@@ -1,52 +0,0 @@
-GEM
-  remote: https://rubygems.org/
-  specs:
-    base64 (0.3.0)
-    bigdecimal (3.2.2)
-    erb (5.0.1)
-    json (2.12.2)
-    logger (1.7.0)
-    mustermann (3.0.3)
-      ruby2_keywords (~> 0.0.1)
-    net-http (0.6.0)
-      uri
-    rack (3.1.16)
-    rack-protection (4.1.1)
-      base64 (>= 0.1.0)
-      logger (>= 1.6.0)
-      rack (>= 3.0.0, < 4)
-    rack-session (2.1.1)
-      base64 (>= 0.1.0)
-      rack (>= 3.0.0)
-    ruby2_keywords (0.0.5)
-    sequel (5.93.0)
-      bigdecimal
-    sinatra (4.1.1)
-      logger (>= 1.6.0)
-      mustermann (~> 3.0)
-      rack (>= 3.0.0, < 4)
-      rack-protection (= 4.1.1)
-      rack-session (>= 2.0.0, < 3)
-      tilt (~> 2.0)
-    tilt (2.6.0)
-    uri (1.0.3)
-    xxhash (0.6.0)
-    zlib (3.2.1)
-
-PLATFORMS
-  ruby
-  x86_64-linux
-
-DEPENDENCIES
-  base64
-  erb
-  json
-  net-http
-  sequel
-  sinatra
-  uri
-  xxhash
-  zlib
-
-BUNDLED WITH
-   2.6.9
diff --git a/dev.fish b/dev.fish
deleted file mode 100644
index 07615e5..0000000
--- a/dev.fish
+++ /dev/null
@@ -1,30 +0,0 @@
-set pipe_path /tmp/infin
-set oldsum (cat (find . \( -name '*.rb' -o -name '*.js' \) | sort) | md5sum)
-if not test -e infinsweeper.db
-  sqlite3 infinsweeper.db < schema.sql
-end
-pkill ruby
-ruby main.rb -p8080 &
-echo "" > $pipe_path
-while true
-  sleep 1
-  set newsum (cat (find . \( -name '*.rb' -o -name '*.js' \) | sort) | md5sum)
-  echo $newsum $oldsum
-  if test "$oldsum" != "$newsum"
-    set oldsum $newsum
-    pkill ruby
-    ruby main.rb -p8080 &
-  end
-  if set line (cat $pipe_path)
-    echo $line
-    if test "$line" = "die"
-      pkill ruby
-      echo "" > $pipe_path
-      exit
-    end
-    if test "$line" = "open"
-      echo "" > $pipe_path
-      xdg-open http://localhost:8080
-    end
-  end
-end
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..5f236ab
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1790185690,
+        "narHash": "sha256-xJ+X4hBtOcAFGBOe5nAMyMUeF9foJBmIOu3NjBqBycU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4975466d324710c576dc11ad614684e6bd8cad8e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..d177f92
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,49 @@
+{
+  description = "Infinsweeper";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    { nixpkgs, ... }:
+    let
+      system = "x86_64-linux";
+      pkgs = nixpkgs.legacyPackages.${system};
+
+      ruby = pkgs.ruby.withPackages (
+        p: with p; [
+          sqlite3
+          sequel
+          rackup
+          puma
+          sinatra
+        ]
+      );
+
+      app = pkgs.stdenv.mkDerivation {
+        pname = "infinsweeper";
+        version = "0.1.0";
+        src = ./.;
+        buildInputs = [ ruby ];
+        installPhase = ''
+          mkdir -p $out
+          cp -r . $out/
+        '';
+        postFixup = ''
+          substituteInPlace $out/bin/infinsweeper \
+            --replace-fail '#!/usr/bin/env ruby' '#!${ruby}/bin/ruby'
+        '';
+      };
+    in
+    {
+      packages.${system}.default = app;
+
+      devShells.${system}.default = pkgs.mkShell {
+        packages = [
+          ruby
+          pkgs.sqlite
+        ];
+      };
+    };
+}
diff --git a/main.rb b/main.rb
index 6db71b4..4f2d420 100644
--- a/main.rb
+++ b/main.rb
@@ -5,7 +5,6 @@ require "net/http"
 require "sequel"
 require "sinatra"
 require "uri"
-require "xxhash"
 require "zlib"
 
 ALPHANUM = [*"0".."9", *"A".."Z", *"a".."z", "-", "_"].freeze
@@ -21,15 +20,32 @@ end
 load "logman.rb"
 # Logman.log ENV_HASH.inspect
 
-db_file = File.expand_path("infinsweeper.db")
+db_file = File.expand_path("infinsweeper.db", __dir__)
 DB = Sequel.connect("sqlite:///#{db_file}", single_threaded: false)
 DB.run("PRAGMA foreign_keys = ON;")
+DB.create_table? :Players do
+  String :username, primary_key: true
+  String :email, unique: true
+  File :digest
+  File :data
+  String :activation_code
+  String :new_pass_code
+  DateTime :created_at, default: Sequel::CURRENT_TIMESTAMP
+end
+DB.create_table? :SignedInUsers do
+  String :code, primary_key: true
+  String :player
+  DateTime :created_at, default: Sequel::CURRENT_TIMESTAMP
+  DateTime :last_used_at, default: Sequel::CURRENT_TIMESTAMP
+  foreign_key [:player], :Players, key: :username, on_delete: :cascade
+end
 $active_users = DB[:SignedInUsers].all.map { |x| [x[:code], x[:player]] }.to_h
 
 load "mailer.rb"
 load "players.rb"
 load "session.rb"
 
+set :port, ENV.fetch("PORT", 5161)
 set :public_folder, "public"
 
 get "/" do
diff --git a/players.rb b/players.rb
index 94222e0..3c3e7a3 100644
--- a/players.rb
+++ b/players.rb
@@ -18,7 +18,7 @@ module Players
     raise ArgumentError, "Password must be at least 8 characters and of valid format." unless
       pass.match?(/\A[a-zA-Z0-9_.!?@#$%^&*()+=-]+\z/) && pass.length >= 8
 
-    digest = XXhash.xxh32(pass, ENV_HASH["SALT"])
+    digest = Zlib.crc32(pass, ENV_HASH["SALT"])
     code = ENV_HASH["ENV"] == "prod" ? Array.new(24) { ALPHANUM.sample }.join : "!"
 
     DB[
@@ -78,7 +78,7 @@ module Players
   end
 
   def self.authorized?(username, pass)
-    digest = XXhash.xxh32(pass, ENV_HASH["SALT"])
+    digest = Zlib.crc32(pass, ENV_HASH["SALT"])
     Logman.log "Authorized: #{username} & #{digest}"
     player = self[username]
     player && player[:digest].to_i == digest.to_i ? player : false