diff --git a/lib/mix/tasks/phx/install/dashboard.ex b/lib/mix/tasks/phx/install/dashboard.ex
index 18ce436..458ae3d 100644
--- a/lib/mix/tasks/phx/install/dashboard.ex
+++ b/lib/mix/tasks/phx/install/dashboard.ex
@@ -29,7 +29,8 @@ defmodule Mix.Tasks.Phx.Install.Dashboard do
     %Igniter.Mix.Task.Info{
       group: :phoenix,
       example: "mix phx.install.dashboard",
-      adds_deps: [{:phoenix_live_dashboard, "~> 0.8"}]
+      adds_deps: [{:phoenix_live_dashboard, "~> 0.8"}],
+      composes: ["phx.install.endpoint", "phx.install.live"]
     }
   end
 
@@ -43,10 +44,15 @@ defmodule Mix.Tasks.Phx.Install.Dashboard do
     igniter
     |> Igniter.Project.Deps.add_dep({:phoenix, "~> 1.7"})
     |> Igniter.Project.Deps.add_dep({:phoenix_live_dashboard, "~> 0.8"})
+    |> Igniter.compose_task("phx.install.endpoint")
+    |> Igniter.compose_task("phx.install.live")
     |> add_dashboard_route(app_name, router_module, telemetry_module)
   end
 
   defp add_dashboard_route(igniter, app_name, router_module, telemetry_module) do
+    dashboard_call =
+      ~s|live_dashboard "/dashboard", metrics: #{inspect(telemetry_module)}|
+
     dev_routes_code = """
     if Application.compile_env(#{inspect(app_name)}, :dev_routes) do
       import Phoenix.LiveDashboard.Router
@@ -54,7 +60,7 @@ defmodule Mix.Tasks.Phx.Install.Dashboard do
       scope "/dev" do
         pipe_through :browser
 
-        live_dashboard "/dashboard", metrics: #{inspect(telemetry_module)}
+        #{dashboard_call}
       end
     end
     """
@@ -66,33 +72,88 @@ defmodule Mix.Tasks.Phx.Install.Dashboard do
              [1, 2],
              &Igniter.Code.Function.argument_equals?(&1, 0, "/dashboard")
            ) do
-        {:ok, _} -> {:ok, zipper}
-        :error -> insert_dashboard_route(zipper, app_name, dev_routes_code)
+        {:ok, _} ->
+          {:ok, zipper}
+
+        :error ->
+          insert_dashboard_route(zipper, dashboard_call, dev_routes_code)
       end
     end)
   end
 
-  defp insert_dashboard_route(zipper, app_name, dev_routes_code) do
-    case find_dev_routes_block(zipper, app_name) do
-      {:ok, _} ->
+  defp insert_dashboard_route(zipper, dashboard_call, dev_routes_code) do
+    case find_dev_routes_block(zipper) do
+      {:ok, dev_routes_zipper} ->
+        add_dashboard_to_existing_dev_scope(dev_routes_zipper, dashboard_call, dev_routes_code)
+
+      :error ->
+        {:ok, Igniter.Code.Common.add_code(zipper, dev_routes_code)}
+    end
+  end
+
+  defp add_dashboard_to_existing_dev_scope(dev_routes_zipper, dashboard_call, dev_routes_code) do
+    with {:ok, body_zipper} <- Igniter.Code.Common.move_to_do_block(dev_routes_zipper),
+         {:ok, scope_zipper} <-
+           Igniter.Code.Function.move_to_function_call_in_current_scope(
+             body_zipper,
+             :scope,
+             [1, 2],
+             &Igniter.Code.Function.argument_equals?(&1, 0, "/dev")
+           ) do
+      import_code = "import Phoenix.LiveDashboard.Router"
+      with_import = Igniter.Code.Common.add_code(scope_zipper, import_code, placement: :before)
+
+      fresh_zipper =
+        with_import
+        |> Sourceror.Zipper.root()
+        |> Sourceror.Zipper.zip()
+
+      with {:ok, dev_routes2} <- find_dev_routes_block(fresh_zipper),
+           {:ok, body2} <- Igniter.Code.Common.move_to_do_block(dev_routes2),
+           {:ok, scope2} <-
+             Igniter.Code.Function.move_to_function_call_in_current_scope(
+               body2,
+               :scope,
+               [1, 2],
+               &Igniter.Code.Function.argument_equals?(&1, 0, "/dev")
+             ),
+           {:ok, scope_body2} <- Igniter.Code.Common.move_to_do_block(scope2) do
+        {:ok, Igniter.Code.Common.add_code(scope_body2, dashboard_call)}
+      else
+        _ ->
+          {:warning,
+           Igniter.Util.Warning.formatted_warning(
+             "Found existing dev_routes block but couldn't add dashboard route. Please add manually:",
+             dev_routes_code
+           )}
+      end
+    else
+      _ ->
         {:warning,
          Igniter.Util.Warning.formatted_warning(
-           "Found existing dev_routes block but couldn't add dashboard. Please add manually:",
+           "Found existing dev_routes block but couldn't add dashboard route. Please add manually:",
            dev_routes_code
          )}
-
-      :error ->
-        {:ok, Igniter.Code.Common.add_code(zipper, dev_routes_code)}
     end
   end
 
-  defp find_dev_routes_block(zipper, app_name) do
+  defp find_dev_routes_block(zipper) do
     Igniter.Code.Common.move_to(zipper, fn z ->
       case Sourceror.Zipper.node(z) do
-        {:if, _, [{:compile_env, _, [_, ^app_name, :dev_routes | _]} | _]} -> true
-        {:if, _, [{:compile_env, _, [:erlang, :binary_to_atom, [^app_name | _], _]} | _]} -> true
-        _ -> false
+        {:if, _,
+         [
+           {{:., _, [{:__aliases__, _, [:Application]}, :compile_env]}, _, args}
+           | _
+         ]} ->
+          args_contain_dev_routes?(args)
+
+        _ ->
+          false
       end
     end)
   end
+
+  defp args_contain_dev_routes?([_, {:__block__, _, [:dev_routes]} | _]), do: true
+  defp args_contain_dev_routes?([_, :dev_routes | _]), do: true
+  defp args_contain_dev_routes?(_), do: false
 end
diff --git a/lib/mix/tasks/phx/install/router.ex b/lib/mix/tasks/phx/install/router.ex
index d993646..66e8526 100644
--- a/lib/mix/tasks/phx/install/router.ex
+++ b/lib/mix/tasks/phx/install/router.ex
@@ -22,7 +22,8 @@ defmodule Mix.Tasks.Phx.Install.Router do
   def info(_argv, _composing_task) do
     %Igniter.Mix.Task.Info{
       group: :phoenix,
-      example: "mix phx.install.router"
+      example: "mix phx.install.router",
+      composes: ["phx.install.core"]
     }
   end
 
@@ -33,6 +34,7 @@ defmodule Mix.Tasks.Phx.Install.Router do
 
     igniter
     |> Igniter.Project.Deps.add_dep({:phoenix, "~> 1.7"})
+    |> Igniter.compose_task("phx.install.core")
     |> create_router(web_module)
     |> create_error_json(web_module)
     |> create_conn_case(web_module, endpoint_module)
diff --git a/test/mix/tasks/phx/install/dashboard_test.exs b/test/mix/tasks/phx/install/dashboard_test.exs
index 129f442..1b16da5 100644
--- a/test/mix/tasks/phx/install/dashboard_test.exs
+++ b/test/mix/tasks/phx/install/dashboard_test.exs
@@ -113,5 +113,57 @@ defmodule Mix.Tasks.Phx.Install.DashboardTest do
 
       assert result.issues == []
     end
+
+    test "standalone invocation composes prerequisites and adds browser pipeline" do
+      igniter =
+        test_project()
+        |> Igniter.compose_task("phx.install.dashboard", ["--session-signing-salt", "sessionsalt"])
+        |> apply_igniter!()
+
+      source = Rewrite.source!(igniter.rewrite, "lib/test_web/router.ex")
+      content = Rewrite.Source.get(source, :content)
+
+      assert content =~ "pipeline :browser"
+      assert content =~ "pipe_through" and content =~ ":browser"
+      assert content =~ "live_dashboard"
+    end
+
+    test "adds live_dashboard into existing dev_routes block" do
+      dev_routes_block = """
+      if Application.compile_env(:test, :dev_routes) do
+        scope "/dev" do
+          pipe_through :browser
+        end
+      end
+      """
+
+      igniter =
+        test_project()
+        |> Igniter.compose_task("phx.install.endpoint", ["--session-signing-salt", "sessionsalt"])
+        |> Igniter.compose_task("phx.install.router")
+        |> apply_igniter!()
+        |> Igniter.Project.Module.find_and_update_module!(
+          TestWeb.Router,
+          fn zipper ->
+            {:ok, Igniter.Code.Common.add_code(zipper, dev_routes_block)}
+          end
+        )
+        |> apply_igniter!()
+        |> Igniter.compose_task("phx.install.dashboard")
+        |> apply_igniter!()
+
+      source = Rewrite.source!(igniter.rewrite, "lib/test_web/router.ex")
+      content = Rewrite.Source.get(source, :content)
+
+      assert content =~ "live_dashboard"
+      assert content =~ "import Phoenix.LiveDashboard.Router"
+
+      occurrences =
+        content
+        |> String.split("dev_routes")
+        |> length()
+
+      assert occurrences == 2, "expected exactly one dev_routes block, found #{occurrences - 1}"
+    end
   end
 end
diff --git a/test/mix/tasks/phx/install/router_test.exs b/test/mix/tasks/phx/install/router_test.exs
index 245c0ca..64b31c0 100644
--- a/test/mix/tasks/phx/install/router_test.exs
+++ b/test/mix/tasks/phx/install/router_test.exs
@@ -29,7 +29,7 @@ defmodule Mix.Tasks.Phx.Install.RouterTest do
     test "creates error_json module" do
       test_project()
       |> Igniter.compose_task("phx.install.router")
-      |> assert_creates("lib/test_web/error_json.ex")
+      |> assert_creates("lib/test_web/controllers/error_json.ex")
     end
 
     test "error_json has correct structure" do
@@ -38,7 +38,7 @@ defmodule Mix.Tasks.Phx.Install.RouterTest do
         |> Igniter.compose_task("phx.install.router")
         |> apply_igniter!()
 
-      source = Rewrite.source!(igniter.rewrite, "lib/test_web/error_json.ex")
+      source = Rewrite.source!(igniter.rewrite, "lib/test_web/controllers/error_json.ex")
       content = Rewrite.Source.get(source, :content)
 
       assert content =~ "defmodule TestWeb.ErrorJSON"
@@ -77,7 +77,7 @@ defmodule Mix.Tasks.Phx.Install.RouterTest do
         |> apply_igniter!()
 
       assert igniter.rewrite.sources["lib/my_app_web/router.ex"]
-      assert igniter.rewrite.sources["lib/my_app_web/error_json.ex"]
+      assert igniter.rewrite.sources["lib/my_app_web/controllers/error_json.ex"]
       assert igniter.rewrite.sources["lib/my_app_web/conn_case.ex"]
 
       router_content =