diff --git a/Library/Homebrew/cli/named_args.rb b/Library/Homebrew/cli/named_args.rb
index 1b30ef7d6b9f2..284c18aa9bbe4 100644
--- a/Library/Homebrew/cli/named_args.rb
+++ b/Library/Homebrew/cli/named_args.rb
@@ -256,11 +256,15 @@ def to_paths(only: parent&.only_formula_or_cask, recurse_tap: false)
               paths = []
 
               if formula_path.exist? ||
-                 (!CoreTap.instance.installed? && Homebrew::API::Formula.all_formulae.key?(path.basename.to_s))
+                 (!Homebrew::EnvConfig.no_install_from_api? &&
+                 !CoreTap.instance.installed? &&
+                 Homebrew::API::Formula.all_formulae.key?(path.basename.to_s))
                 paths << formula_path
               end
               if cask_path.exist? ||
-                 (!CoreCaskTap.instance.installed? && Homebrew::API::Cask.all_casks.key?(path.basename.to_s))
+                 (!Homebrew::EnvConfig.no_install_from_api? &&
+                 !CoreCaskTap.instance.installed? &&
+                 Homebrew::API::Cask.all_casks.key?(path.basename.to_s))
                 paths << cask_path
               end
 
diff --git a/Library/Homebrew/test/cask/cask_loader/from_api_loader_spec.rb b/Library/Homebrew/test/cask/cask_loader/from_api_loader_spec.rb
index 7e567e95fe6d4..eb21387245271 100644
--- a/Library/Homebrew/test/cask/cask_loader/from_api_loader_spec.rb
+++ b/Library/Homebrew/test/cask/cask_loader/from_api_loader_spec.rb
@@ -22,11 +22,7 @@
   describe ".can_load?" do
     include_context "with API setup", "test-opera"
 
-    context "when not using the API" do
-      before do
-        ENV["HOMEBREW_NO_INSTALL_FROM_API"] = "1"
-      end
-
+    context "when not using the API", :no_api do
       it "returns false" do
         expect(described_class.try_new(token)).to be_nil
       end
diff --git a/Library/Homebrew/test/cask/cask_loader_spec.rb b/Library/Homebrew/test/cask/cask_loader_spec.rb
index e7fcc9696ec78..62be102cea7b3 100644
--- a/Library/Homebrew/test/cask/cask_loader_spec.rb
+++ b/Library/Homebrew/test/cask/cask_loader_spec.rb
@@ -30,11 +30,7 @@
           .and_return(cask_renames)
       end
 
-      context "when not using the API" do
-        before do
-          ENV["HOMEBREW_NO_INSTALL_FROM_API"] = "1"
-        end
-
+      context "when not using the API", :no_api do
         it "warns when using the short token" do
           expect do
             expect(described_class.for("version-newest")).to be_a Cask::CaskLoader::FromPathLoader
@@ -67,11 +63,7 @@
       end
     end
 
-    context "when not using the API" do
-      before do
-        ENV["HOMEBREW_NO_INSTALL_FROM_API"] = "1"
-      end
-
+    context "when not using the API", :no_api do
       context "when a cask is migrated" do
         let(:token) { "local-caffeine" }
 
diff --git a/Library/Homebrew/test/cask/cask_spec.rb b/Library/Homebrew/test/cask/cask_spec.rb
index fea5589a37025..cadba6516e3d1 100644
--- a/Library/Homebrew/test/cask/cask_spec.rb
+++ b/Library/Homebrew/test/cask/cask_spec.rb
@@ -46,13 +46,13 @@
       expect(c.token).to eq("caffeine")
     end
 
-    it "returns an instance of the Cask from a URL" do
+    it "returns an instance of the Cask from a URL", :needs_utils_curl, :no_api do
       c = Cask::CaskLoader.load("file://#{tap_path}/Casks/local-caffeine.rb")
       expect(c).to be_a(described_class)
       expect(c.token).to eq("local-caffeine")
     end
 
-    it "raises an error when failing to download a Cask from a URL" do
+    it "raises an error when failing to download a Cask from a URL", :needs_utils_curl, :no_api do
       expect do
         Cask::CaskLoader.load("file://#{tap_path}/Casks/notacask.rb")
       end.to raise_error(Cask::CaskUnavailableError)
diff --git a/Library/Homebrew/test/cask/info_spec.rb b/Library/Homebrew/test/cask/info_spec.rb
index 2c5a5aefc0195..8710a8ba70e21 100644
--- a/Library/Homebrew/test/cask/info_spec.rb
+++ b/Library/Homebrew/test/cask/info_spec.rb
@@ -3,6 +3,11 @@
 require "utils"
 
 RSpec.describe Cask::Info, :cask do
+  before do
+    # Prevent unnecessary network requests in `Utils::Analytics.cask_output`
+    ENV["HOMEBREW_NO_ANALYTICS"] = "1"
+  end
+
   it "displays some nice info about the specified Cask" do
     expect do
       described_class.info(Cask::CaskLoader.load("local-transmission"))
diff --git a/Library/Homebrew/test/formulary_spec.rb b/Library/Homebrew/test/formulary_spec.rb
index 86631a3a667dd..3bb7491bdf0c5 100644
--- a/Library/Homebrew/test/formulary_spec.rb
+++ b/Library/Homebrew/test/formulary_spec.rb
@@ -119,7 +119,7 @@ class Wrong#{described_class.class_s(formula_name)} < Formula
       expect(described_class.factory(formula_path)).to be_a(Formula)
     end
 
-    it "returns a Formula when given a URL" do
+    it "returns a Formula when given a URL", :needs_utils_curl, :no_api do
       formula = described_class.factory("file://#{formula_path}")
       expect(formula).to be_a(Formula)
     end
@@ -383,6 +383,10 @@ def formula_json_contents(extra_items = {})
       before do
         ENV.delete("HOMEBREW_NO_INSTALL_FROM_API")
 
+        # avoid unnecessary network calls
+        allow(Homebrew::API::Formula).to receive_messages(all_aliases: {}, all_renames: {})
+        allow(CoreTap.instance).to receive(:tap_migrations).and_return({})
+
         # don't try to load/fetch gcc/glibc
         allow(DevelopmentTools).to receive_messages(needs_libc_formula?: false, needs_compiler_formula?: false)
       end
diff --git a/Library/Homebrew/test/spec_helper.rb b/Library/Homebrew/test/spec_helper.rb
index bb08dd6e5a661..70fa46df38f5b 100644
--- a/Library/Homebrew/test/spec_helper.rb
+++ b/Library/Homebrew/test/spec_helper.rb
@@ -165,6 +165,19 @@
     skip "Requires network connection." unless ENV["HOMEBREW_TEST_ONLINE"]
   end
 
+  config.before do |example|
+    next if example.metadata.key?(:needs_network)
+    next if example.metadata.key?(:needs_utils_curl)
+
+    allow(Utils::Curl).to receive(:curl_executable).and_raise(<<~ERROR)
+      Unexpected call to Utils::Curl.curl_executable without setting :needs_network or :needs_utils_curl.
+    ERROR
+  end
+
+  config.before(:each, :no_api) do
+    ENV["HOMEBREW_NO_INSTALL_FROM_API"] = "1"
+  end
+
   config.before(:each, :needs_svn) do
     svn_shim = HOMEBREW_SHIMS_PATH/"shared/svn"
     skip "Subversion is not installed." unless quiet_system svn_shim, "--version"
diff --git a/Library/Homebrew/test/tap_spec.rb b/Library/Homebrew/test/tap_spec.rb
index 8ea9116037af9..ecfa2b8996aa3 100644
--- a/Library/Homebrew/test/tap_spec.rb
+++ b/Library/Homebrew/test/tap_spec.rb
@@ -192,7 +192,7 @@ def setup_completion(link:)
   end
 
   describe "#remote" do
-    it "returns the remote URL" do
+    it "returns the remote URL", :needs_network do
       setup_git_repo
 
       expect(homebrew_foo_tap.remote).to eq("https://github.com/Homebrew/homebrew-foo")
@@ -488,8 +488,7 @@ def setup_completion(link:)
         expect(described_class.to_a).to include(CoreTap.instance)
       end
 
-      it "omits the core tap without the api" do
-        ENV["HOMEBREW_NO_INSTALL_FROM_API"] = "1"
+      it "omits the core tap without the api", :no_api do
         expect(described_class.to_a).not_to include(CoreTap.instance)
       end
     end