diff --git a/t/hint_foundries.t b/t/hint_foundries.t
new file mode 100644
index 0000000..e427bdf
--- /dev/null
+++ b/t/hint_foundries.t
@@ -0,0 +1,165 @@
+use Mojo::Base -strict;
+use Test::More;
+use Test::Mojo;
+
+# Test 1: Default foundries (no configuration)
+subtest 'Default foundries' => sub {
+  my $t = Test::Mojo->new('Kalamar');
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  is_deeply(
+    $defaults,
+    [qw(base corenlp dereko malt marmot opennlp spacy tt)],
+    'Default foundries are set correctly'
+  );
+  
+  # Check that data-hint-foundries is rendered in HTML
+  $t->get_ok('/')
+    ->status_is(200)
+    ->attr_like('body', 'data-hint-foundries', qr/base/)
+    ->attr_like('body', 'data-hint-foundries', qr/corenlp/)
+    ->attr_like('body', 'data-hint-foundries', qr/spacy/);
+};
+
+
+# Test 2: Custom foundries via config (inclusions only)
+subtest 'Custom foundries via config' => sub {
+  my $t = Test::Mojo->new('Kalamar' => {
+    Kalamar => {
+      hint_foundries => ['base', 'marmot', 'tt']
+    }
+  });
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  is_deeply(
+    $defaults,
+    ['base', 'marmot', 'tt'],
+    'Custom foundries are set correctly'
+  );
+  
+  $t->get_ok('/')
+    ->status_is(200)
+    ->attr_like('body', 'data-hint-foundries', qr/base/)
+    ->attr_like('body', 'data-hint-foundries', qr/marmot/)
+    ->attr_like('body', 'data-hint-foundries', qr/tt/)
+    ->attr_unlike('body', 'data-hint-foundries', qr/corenlp/)
+    ->attr_unlike('body', 'data-hint-foundries', qr/spacy/);
+};
+
+
+# Test 3: Exclusions via config (e.g., -spacy, -corenlp)
+subtest 'Exclusions via config' => sub {
+  my $t = Test::Mojo->new('Kalamar' => {
+    Kalamar => {
+      hint_foundries => ['-spacy', '-corenlp']
+    }
+  });
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  
+  # Should contain all defaults except spacy and corenlp
+  ok((grep { $_ eq 'base' } @$defaults), 'Contains base');
+  ok((grep { $_ eq 'dereko' } @$defaults), 'Contains dereko');
+  ok((grep { $_ eq 'malt' } @$defaults), 'Contains malt');
+  ok((grep { $_ eq 'marmot' } @$defaults), 'Contains marmot');
+  ok((grep { $_ eq 'opennlp' } @$defaults), 'Contains opennlp');
+  ok((grep { $_ eq 'tt' } @$defaults), 'Contains tt');
+  ok(!(grep { $_ eq 'spacy' } @$defaults), 'Does not contain spacy');
+  ok(!(grep { $_ eq 'corenlp' } @$defaults), 'Does not contain corenlp');
+  
+  $t->get_ok('/')
+    ->status_is(200)
+    ->attr_like('body', 'data-hint-foundries', qr/base/)
+    ->attr_unlike('body', 'data-hint-foundries', qr/spacy/)
+    ->attr_unlike('body', 'data-hint-foundries', qr/corenlp/);
+};
+
+
+# Test 4: Environment variable KALAMAR_HINT_FOUNDRIES
+subtest 'Environment variable' => sub {
+  local $ENV{KALAMAR_HINT_FOUNDRIES} = 'base,tt,marmot';
+  
+  my $t = Test::Mojo->new('Kalamar');
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  is_deeply(
+    $defaults,
+    ['base', 'tt', 'marmot'],
+    'Foundries from environment variable'
+  );
+  
+  $t->get_ok('/')
+    ->status_is(200)
+    ->attr_like('body', 'data-hint-foundries', qr/base,tt,marmot/);
+};
+
+
+# Test 5: Environment variable with exclusions
+subtest 'Environment variable with exclusions' => sub {
+  local $ENV{KALAMAR_HINT_FOUNDRIES} = '-spacy,-opennlp';
+  
+  my $t = Test::Mojo->new('Kalamar');
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  
+  ok((grep { $_ eq 'base' } @$defaults), 'Contains base');
+  ok((grep { $_ eq 'corenlp' } @$defaults), 'Contains corenlp');
+  ok(!(grep { $_ eq 'spacy' } @$defaults), 'Does not contain spacy');
+  ok(!(grep { $_ eq 'opennlp' } @$defaults), 'Does not contain opennlp');
+};
+
+
+# Test 6: Environment variable overrides config
+subtest 'Environment variable overrides config' => sub {
+  local $ENV{KALAMAR_HINT_FOUNDRIES} = 'base,tt';
+  
+  my $t = Test::Mojo->new('Kalamar' => {
+    Kalamar => {
+      hint_foundries => ['corenlp', 'marmot', 'spacy']
+    }
+  });
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  is_deeply(
+    $defaults,
+    ['base', 'tt'],
+    'Environment variable takes precedence over config'
+  );
+};
+
+
+# Test 7: Empty config foundries array uses defaults
+subtest 'Empty config uses defaults' => sub {
+  my $t = Test::Mojo->new('Kalamar' => {
+    Kalamar => {
+      hint_foundries => []
+    }
+  });
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  is_deeply(
+    $defaults,
+    [qw(base corenlp dereko malt marmot opennlp spacy tt)],
+    'Empty array results in defaults'
+  );
+};
+
+
+# Test 8: Case insensitivity of exclusions
+subtest 'Case insensitive exclusions' => sub {
+  my $t = Test::Mojo->new('Kalamar' => {
+    Kalamar => {
+      hint_foundries => ['-SPACY', '-CoreNLP']
+    }
+  });
+  
+  my $defaults = $t->app->defaults('hint_foundries');
+  
+  ok(!(grep { lc($_) eq 'spacy' } @$defaults), 'Does not contain spacy (case insensitive)');
+  ok(!(grep { lc($_) eq 'corenlp' } @$defaults), 'Does not contain corenlp (case insensitive)');
+  ok((grep { $_ eq 'base' } @$defaults), 'Still contains base');
+};
+
+
+done_testing;
+__END__