oapi-codegen · mromaszewicz · Feb 24, 2026 · Feb 24, 2026
@@ -0,0 +1,5 @@
+package: issue2232
+output: issue2232.gen.go
+generate:
+  std-http-server: true
+  models: true
@@ -0,0 +1,3 @@
+package issue2232
+
+//go:generate go run github.com/oapi-codegen/oapi-codegen/v2/cmd/oapi-codegen --config=config.yaml spec.yaml
@@ -0,0 +1,41 @@
+package issue2232
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestExtraTagsOnQueryParams verifies that x-oapi-codegen-extra-tags is applied
+// to query parameter struct fields regardless of whether the extension is placed
+// at the parameter level or at the schema level within the parameter.
+// This is a regression test for https://github.com/oapi-codegen/oapi-codegen/issues/2232
+func TestExtraTagsOnQueryParams(t *testing.T) {
+	paramType := reflect.TypeOf(GetEndpointParams{})
+
+	t.Run("parameter-level extension", func(t *testing.T) {
+		field, ok := paramType.FieldByName("EnvParamLevel")
+		require.True(t, ok, "field EnvParamLevel should exist")
+
+		assert.Equal(t, `required,oneof=dev live`, field.Tag.Get("validate"),
+			"x-oapi-codegen-extra-tags at parameter level should produce validate tag")
+	})
+
+	t.Run("schema-level extension", func(t *testing.T) {
+		field, ok := paramType.FieldByName("EnvSchemaLevel")
+		require.True(t, ok, "field EnvSchemaLevel should exist")
+
+		assert.Equal(t, `required,oneof=dev live`, field.Tag.Get("validate"),
+			"x-oapi-codegen-extra-tags at schema level within a parameter should produce validate tag")
+	})
+
+	t.Run("schema-level extension on optional param", func(t *testing.T) {
+		field, ok := paramType.FieldByName("Limit")
+		require.True(t, ok, "field Limit should exist")
+
+		assert.Equal(t, `min=0,max=100`, field.Tag.Get("validate"),
+			"x-oapi-codegen-extra-tags at schema level within an optional parameter should produce validate tag")
+	})
+}
@@ -0,0 +1,46 @@
+openapi: "3.0.3"
+info:
+  title: test
+  version: 1.0.0
+paths:
+  /v1/endpoint:
+    get:
+      operationId: GetEndpoint
+      parameters:
+        - name: env_param_level
+          in: query
+          required: true
+          schema:
+            type: string
+            enum:
+              - dev
+              - live
+          x-oapi-codegen-extra-tags:
+            validate: "required,oneof=dev live"
+        - name: env_schema_level
+          in: query
+          required: true
+          schema:
+            type: string
+            enum:
+              - dev
+              - live
+            x-oapi-codegen-extra-tags:
+              validate: "required,oneof=dev live"
+        - name: limit
+          in: query
+          required: false
+          schema:
+            type: integer
+            x-oapi-codegen-extra-tags:
+              validate: "min=0,max=100"
+      responses:
+        "200":
+          description: Success
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  message:
+                    type: string
@@ -925,13 +925,24 @@ func GenerateParamsTypes(op OperationDefinition) []TypeDefinition {
 				Schema:   param.Schema,
 			})
 		}
+		// Merge extensions from the schema level and the parameter level.
+		// Parameter-level extensions take precedence over schema-level ones.
+		extensions := make(map[string]any)
+		if param.Spec.Schema != nil && param.Spec.Schema.Value != nil {
+			for k, v := range param.Spec.Schema.Value.Extensions {
+				extensions[k] = v
+			}
+		}
+		for k, v := range param.Spec.Extensions {
+			extensions[k] = v
+		}
 		prop := Property{
 			Description:   param.Spec.Description,
 			JsonFieldName: param.ParamName,
 			Required:      param.Required,
 			Schema:        pSchema,
 			NeedsFormTag:  param.Style() == "form",
-			Extensions:    param.Spec.Extensions,
+			Extensions:    extensions,
 		}
 		s.Properties = append(s.Properties, prop)
 	}
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		package issue2232

		//go:generate go run github.com/oapi-codegen/oapi-codegen/v2/cmd/oapi-codegen --config=config.yaml spec.yaml