Preserve positional options for named params

CHANGELOG.md

@@ -56,6 +56,7 @@
 * [#2829](https://github.com/ruby-grape/grape/pull/2829): Fix a cascading route handing over only to the last route registered for the path, making a middle version (3+ mounted versions with a catch-all) answer 406 - [@ericproulx](https://github.com/ericproulx).
 * [#2826](https://github.com/ruby-grape/grape/pull/2826): Fix `api.version` not being set for the root route of a path-versioned API (`GET /v1`) - [@ericproulx](https://github.com/ericproulx).
 * [#2842](https://github.com/ruby-grape/grape/pull/2842): Warn at definition time when a `rescue_from` class is already covered by one registered earlier in the same scope, since the later handler never runs - [@ericproulx](https://github.com/ericproulx).
+* [#2852](https://github.com/ruby-grape/grape/pull/2852): Preserve positional options hashes passed to named params - [@cyphercodes](https://github.com/cyphercodes).
 * Your contribution here.
 
 ### 3.3.5 (2026-07-30)

lib/grape/dsl/parameters.rb

@@ -54,6 +54,8 @@ def build_with(build_with)
       #       end
       #     end
       def use(*names, **options)
+        options = names.pop if options.empty? && names.size > 1 && names.last.is_a?(Hash)
+
         named_params = @api.inheritable_setting.named_params || {}
         names.each do |name|
           params_block = named_params.fetch(name) do

spec/grape/dsl/parameters_spec.rb

@@ -63,6 +63,13 @@ def new_group_scope(group)
       subject.use :params_group, **options
     end
 
+    it 'extracts a positional options hash from named params' do
+      subject.api = Class.new { include Grape::DSL::Settings }.new
+      subject.api.inheritable_setting.add_named_params(named_params)
+      expect(subject).to receive(:instance_exec).with(options).and_yield
+      subject.use :params_group, options
+    end
+
     it 'raises error when non-existent named param is called' do
       subject.api = Class.new { include Grape::DSL::Settings }.new
       expect { subject.use :params_group }.to raise_error('Params :params_group not found!')