diff --git a/lib/mix/tasks/beacon.gen.site.ex b/lib/mix/tasks/beacon.gen.site.ex
index 55655bd19..37dee39da 100644
--- a/lib/mix/tasks/beacon.gen.site.ex
+++ b/lib/mix/tasks/beacon.gen.site.ex
@@ -54,6 +54,7 @@ defmodule Mix.Tasks.Beacon.Gen.Site do
     otp_app = Igniter.Project.Application.app_name(igniter)
     web_module = Igniter.Libs.Phoenix.web_module(igniter)
     {igniter, router} = Beacon.Igniter.select_router!(igniter)
+    {igniter, existing_endpoints} = Igniter.Libs.Phoenix.endpoints_for_router(igniter, router)
     repo = Igniter.Project.Module.module_name(igniter, "Repo")
 
     igniter
@@ -66,6 +67,8 @@ defmodule Mix.Tasks.Beacon.Gen.Site do
     |> maybe_create_proxy_endpoint(host, signing_salt, secret_key_base)
     |> maybe_create_new_endpoint(host, otp_app, web_module)
     |> maybe_configure_new_endpoint(host, otp_app, port, secure_port, secret_key_base, signing_salt)
+    |> maybe_update_existing_endpoints(host, otp_app, existing_endpoints, signing_salt, secret_key_base)
+    |> maybe_update_session_options(host, otp_app, signing_salt)
     |> maybe_add_new_endpoint_to_application(host, repo)
     |> Igniter.add_notice("""
     Site #{inspect(site)} generated successfully.
@@ -245,7 +248,7 @@ defmodule Mix.Tasks.Beacon.Gen.Site do
   defp maybe_create_proxy_endpoint(igniter, nil, _, _), do: igniter
 
   defp maybe_create_proxy_endpoint(igniter, _host, signing_salt, secret_key_base),
-    do: Igniter.compose_task(igniter, "beacon.gen.proxy_endpoint", signing_salt: signing_salt, secret_key_base: secret_key_base)
+    do: Igniter.compose_task(igniter, "beacon.gen.proxy_endpoint", ~w(--signing-salt #{signing_salt} --secret-key-base #{secret_key_base}))
 
   defp maybe_create_new_endpoint(igniter, nil, _, _), do: igniter
 
@@ -370,6 +373,22 @@ defmodule Mix.Tasks.Beacon.Gen.Site do
     )
   end
 
+  defp maybe_update_existing_endpoints(igniter, nil, _, _, _, _), do: igniter
+
+  defp maybe_update_existing_endpoints(igniter, _host, otp_app, existing_endpoints, signing_salt, secret_key_base) do
+    Enum.reduce(existing_endpoints, igniter, fn endpoint, acc ->
+      acc
+      |> Igniter.Project.Config.configure("config.exs", otp_app, [endpoint, :live_view, :signing_salt], signing_salt)
+      |> Igniter.Project.Config.configure("dev.exs", otp_app, [endpoint, :secret_key_base], secret_key_base)
+    end)
+  end
+
+  defp maybe_update_session_options(igniter, nil, _, _), do: igniter
+
+  defp maybe_update_session_options(igniter, _host, otp_app, signing_salt) do
+    Igniter.Project.Config.configure(igniter, "config.exs", otp_app, [:session_options, :signing_salt], signing_salt)
+  end
+
   defp maybe_add_new_endpoint_to_application(igniter, nil, _), do: igniter
 
   defp maybe_add_new_endpoint_to_application(igniter, host, repo) do
diff --git a/test/mix/tasks/gen_site_test.exs b/test/mix/tasks/gen_site_test.exs
index 00d672047..01e1d9cfd 100644
--- a/test/mix/tasks/gen_site_test.exs
+++ b/test/mix/tasks/gen_site_test.exs
@@ -214,6 +214,7 @@ defmodule Mix.Tasks.Beacon.GenSiteTest do
     test "updates config.exs", %{project: project} do
       project
       |> Igniter.compose_task("beacon.gen.site", @opts_host)
+      # add config for new endpoint
       |> assert_has_patch("config/config.exs", """
          10 + |config :test, TestWeb.ExampleEndpoint,
          11 + |  url: [host: "localhost"],
@@ -225,11 +226,20 @@ defmodule Mix.Tasks.Beacon.GenSiteTest do
          17 + |  pubsub_server: Test.PubSub,
          18 + |  live_view: [signing_salt: "#{@signing_salt}"]
       """)
+      # update signing salt for host app session_options
+      |> assert_has_patch("config/config.exs", """
+         28 + |    signing_salt: "#{@signing_salt}",
+      """)
+      # update signing salt for existing endpoint
+      |> assert_has_patch("config/config.exs", """
+         41 + |  live_view: [signing_salt: "#{@signing_salt}"]
+      """)
     end
 
     test "updates dev.exs", %{project: project} do
       project
       |> Igniter.compose_task("beacon.gen.site", @opts_host)
+      # add config for new endpoint
       |> assert_has_patch("config/dev.exs", """
          3 + |config :test, TestWeb.ExampleEndpoint,
          4 + |  http: [ip: {127, 0, 0, 1}, port: #{@port}],
@@ -243,6 +253,10 @@ defmodule Mix.Tasks.Beacon.GenSiteTest do
         12 + |  ]
         13 + |
       """)
+      # update secret key base for existing endpoint
+      |> assert_has_patch("config/dev.exs", """
+          33 + |  secret_key_base: "#{@secret_key_base}",
+      """)
     end
 
     test "updates runtime.exs", %{project: project} do
@@ -256,7 +270,7 @@ defmodule Mix.Tasks.Beacon.GenSiteTest do
         57 + |
       """)
       |> assert_has_patch("config/runtime.exs", """
-        48 + |    check_origin: ["example.com"],
+        48 + |    check_origin: [host, "example.com"],
       """)
       |> assert_has_patch("config/runtime.exs", """
          2 + |config :beacon, my_site: [site: :my_site, repo: Test.Repo, endpoint: TestWeb.ExampleEndpoint, router: TestWeb.Router]