diff --git a/.env.example b/.env.example
new file mode 100644
index 00000000..48c81b0f
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,12 @@
+# Local DocuSeal dev env. Copy to `.env` (gitignored). Loaded by foreman.
+
+# Port DocuSeal Puma binds to. Health Rails API runs on 3000, so use 3030.
+PORT=3030
+
+# Postgres dev DB. Create with: createdb docuseal_dev
+DATABASE_URL=postgres:///docuseal_dev
+
+# Webpacker / shakapacker dev-server port (default 3035; left alone).
+
+# Override host base URL used in generated links if needed.
+# HOST=http://localhost:3030
diff --git a/.gitignore b/.gitignore
index d14f4595..52d805f4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 /.bundle
+/vendor/bundle
 
 /db/*.sqlite3
 /db/*.sqlite3-*
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 00000000..4d54dadd
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+4.0.2
diff --git a/Gemfile b/Gemfile
index 4e2fd78e..a4bda694 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,7 +2,7 @@
 
 source 'https://rubygems.org'
 
-ruby '4.0.1'
+ruby '~> 4.0'
 
 gem 'addressable'
 gem 'arabic-letter-connector', require: false
diff --git a/Procfile.dev b/Procfile.dev
index b26b8715..359012c7 100644
--- a/Procfile.dev
+++ b/Procfile.dev
@@ -1,2 +1,2 @@
-web: PORT=3000 bundle exec rails s -p 3000
+web: PORT=${PORT:-3000} bundle exec rails s -p ${PORT:-3000}
 webpacker: bundle exec ./bin/shakapacker-dev-server