diff --git a/Library/Homebrew/api.rb b/Library/Homebrew/api.rb
index fdcab5005f..25da80be19 100644
--- a/Library/Homebrew/api.rb
+++ b/Library/Homebrew/api.rb
@@ -152,6 +152,30 @@ module Homebrew
       json.except("variations")
     end
 
+    sig { params(download_queue: T.nilable(DownloadQueue), stale_seconds: Integer).void }
+    def self.fetch_api_files!(download_queue: nil, stale_seconds: Homebrew::EnvConfig.api_auto_update_secs.to_i)
+      if ENV.fetch("HOMEBREW_USE_INTERNAL_API", false).present?
+        Homebrew::API::Internal.fetch_formula_api!(download_queue:, stale_seconds:)
+        Homebrew::API::Internal.fetch_cask_api!(download_queue:, stale_seconds:)
+      else
+        Homebrew::API::Formula.fetch_api!(download_queue:, stale_seconds:)
+        Homebrew::API::Formula.fetch_tap_migrations!(download_queue:, stale_seconds:)
+        Homebrew::API::Cask.fetch_api!(download_queue:, stale_seconds:)
+        Homebrew::API::Cask.fetch_tap_migrations!(download_queue:, stale_seconds:)
+      end
+    end
+
+    sig { void }
+    def self.write_names_and_aliases
+      if ENV.fetch("HOMEBREW_USE_INTERNAL_API", nil)
+        Homebrew::API::Internal.write_formula_names_and_aliases
+        Homebrew::API::Internal.write_cask_names
+      else
+        Homebrew::API::Formula.write_names_and_aliases
+        Homebrew::API::Cask.write_names
+      end
+    end
+
     sig { params(names: T::Array[String], type: String, regenerate: T::Boolean).returns(T::Boolean) }
     def self.write_names_file!(names, type, regenerate:)
       names_path = HOMEBREW_CACHE_API/"#{type}_names.txt"
diff --git a/Library/Homebrew/brew.rb b/Library/Homebrew/brew.rb
index aced177b90..f38ef7ec7e 100644
--- a/Library/Homebrew/brew.rb
+++ b/Library/Homebrew/brew.rb
@@ -95,10 +95,7 @@ begin
         require "api/cask"
         download_queue = Homebrew::DownloadQueue.new
         stale_seconds = 86400 # 1 day
-        Homebrew::API::Formula.fetch_api!(download_queue:, stale_seconds:)
-        Homebrew::API::Formula.fetch_tap_migrations!(download_queue:, stale_seconds:)
-        Homebrew::API::Cask.fetch_api!(download_queue:, stale_seconds:)
-        Homebrew::API::Cask.fetch_tap_migrations!(download_queue:, stale_seconds:)
+        Homebrew::API.fetch_api_files!(download_queue:, stale_seconds:)
         begin
           download_queue.fetch
         ensure
diff --git a/Library/Homebrew/cmd/update-report.rb b/Library/Homebrew/cmd/update-report.rb
index 38c84d2e02..a7d9ce6b60 100644
--- a/Library/Homebrew/cmd/update-report.rb
+++ b/Library/Homebrew/cmd/update-report.rb
@@ -134,10 +134,7 @@ module Homebrew
         end
 
         # Check if we can parse the JSON and do any Ruby-side follow-up.
-        unless Homebrew::EnvConfig.no_install_from_api?
-          Homebrew::API::Formula.write_names_and_aliases
-          Homebrew::API::Cask.write_names
-        end
+        Homebrew::API.write_names_and_aliases unless Homebrew::EnvConfig.no_install_from_api?
 
         Homebrew.failed = true if ENV["HOMEBREW_UPDATE_FAILED"]
         return if Homebrew::EnvConfig.disable_load_formula?