diff --git a/.changepacks/changepack_log_mKVkBobmisQ7I7wMUlrDR.json b/.changepacks/changepack_log_mKVkBobmisQ7I7wMUlrDR.json
new file mode 100644
index 0000000..841124e
--- /dev/null
+++ b/.changepacks/changepack_log_mKVkBobmisQ7I7wMUlrDR.json
@@ -0,0 +1 @@
+{"changes":{"Cargo.toml":"Patch"},"note":"Support enum in query","date":"2026-02-18T10:50:32.672936100Z"}
\ No newline at end of file
diff --git a/crates/vespera_macro/src/parser/parameters.rs b/crates/vespera_macro/src/parser/parameters.rs
index 30b7fb3..b814d57 100644
--- a/crates/vespera_macro/src/parser/parameters.rs
+++ b/crates/vespera_macro/src/parser/parameters.rs
@@ -3,7 +3,7 @@ use std::collections::{HashMap, HashSet};
 use syn::{FnArg, Pat, PatType, Type};
 use vespera_core::{
     route::{Parameter, ParameterLocation},
-    schema::{Schema, SchemaRef, SchemaType},
+    schema::{Schema, SchemaRef},
 };
 
 use super::schema::{
@@ -14,9 +14,8 @@ use crate::schema_macro::type_utils::{
     is_map_type as utils_is_map_type, is_primitive_like as utils_is_primitive_like,
 };
 
-/// Convert `SchemaRef` to inline schema for query parameters
-/// Query parameters should always use inline schemas, not refs
-/// Adds nullable flag if the field is optional
+/// Convert `SchemaRef` for query parameters, adding nullable flag if optional.
+/// Preserves `$ref` for known types (e.g. enums) — only wraps with nullable when optional.
 fn convert_to_inline_schema(field_schema: SchemaRef, is_optional: bool) -> SchemaRef {
     match field_schema {
         SchemaRef::Inline(mut schema) => {
@@ -25,12 +24,17 @@ fn convert_to_inline_schema(field_schema: SchemaRef, is_optional: bool) -> Schem
             }
             SchemaRef::Inline(schema)
         }
-        SchemaRef::Ref(_) => {
-            let mut schema = Schema::new(SchemaType::Object);
+        SchemaRef::Ref(r) => {
             if is_optional {
-                schema.nullable = Some(true);
+                SchemaRef::Inline(Box::new(Schema {
+                    ref_path: Some(r.ref_path),
+                    schema_type: None,
+                    nullable: Some(true),
+                    ..Default::default()
+                }))
+            } else {
+                SchemaRef::Ref(r)
             }
-            SchemaRef::Inline(Box::new(schema))
         }
     }
 }
@@ -433,7 +437,7 @@ mod tests {
     use insta::{assert_debug_snapshot, with_settings};
     use rstest::rstest;
     use vespera_core::route::ParameterLocation;
-    use vespera_core::schema::Reference;
+    use vespera_core::schema::{Reference, SchemaType};
 
     use super::*;
 
@@ -1011,16 +1015,11 @@ mod tests {
     }
 
     #[test]
-    fn test_schema_ref_to_inline_conversion_required() {
-        // Test line 318: SchemaRef::Ref converted to inline for required fields
-        // This requires a field where:
-        // 1. field_schema is SchemaRef::Ref
-        // 2. is_optional is false
-        // 3. The ref conversion at lines 294-304 fails (no struct_def)
+    fn test_schema_ref_preserved_for_required_field() {
+        // Required field with known schema but no struct definition → $ref preserved
         let mut struct_definitions = HashMap::new();
         let mut known_schemas = HashSet::new();
 
-        // Struct with required RefType field
         struct_definitions.insert(
             "QueryWithRef".to_string(),
             r"
@@ -1032,7 +1031,7 @@ mod tests {
         );
 
         // RefType is a known schema (will generate SchemaRef::Ref)
-        // BUT we don't have its struct definition, so the conversion at 296-303 fails
+        // No struct definition, so ref stays as-is (e.g. enum type)
         known_schemas.insert("RefType".to_string());
 
         let ty: Type = syn::parse_str("QueryWithRef").unwrap();
@@ -1041,12 +1040,12 @@ mod tests {
         assert!(result.is_some());
         let params = result.unwrap();
         assert_eq!(params.len(), 1);
-        // Line 318: Ref that couldn't be converted is turned into inline object
+        // $ref is preserved for required fields
         match &params[0].schema {
-            Some(SchemaRef::Inline(schema)) => {
-                assert_eq!(schema.schema_type, Some(SchemaType::Object));
+            Some(SchemaRef::Ref(r)) => {
+                assert_eq!(r.ref_path, "#/components/schemas/RefType");
             }
-            _ => panic!("Expected inline schema (converted from Ref)"),
+            _ => panic!("Expected $ref schema for required known type"),
         }
     }
 
@@ -1122,30 +1121,161 @@ mod tests {
     }
 
     #[test]
-    fn test_convert_to_inline_schema_with_ref_optional() {
+    fn test_convert_to_inline_schema_ref_optional_preserves_ref_path() {
         let schema = SchemaRef::Ref(Reference {
             ref_path: "#/components/schemas/User".to_string(),
         });
         let result = convert_to_inline_schema(schema, true);
         match result {
             SchemaRef::Inline(s) => {
+                assert_eq!(s.ref_path, Some("#/components/schemas/User".to_string()));
                 assert_eq!(s.nullable, Some(true));
+                assert_eq!(s.schema_type, None);
             }
-            SchemaRef::Ref(_) => panic!("Expected Inline"),
+            SchemaRef::Ref(_) => panic!("Expected Inline wrapper for optional $ref"),
         }
     }
 
     #[test]
-    fn test_convert_to_inline_schema_ref_optional() {
+    fn test_convert_to_inline_schema_ref_required_passes_through() {
+        use vespera_core::schema::Reference;
+        let schema = SchemaRef::Ref(Reference::schema("SomeType"));
+        let result = convert_to_inline_schema(schema, false);
+        match result {
+            SchemaRef::Ref(r) => {
+                assert_eq!(r.ref_path, "#/components/schemas/SomeType");
+            }
+            SchemaRef::Inline(_) => panic!("Expected $ref pass-through for required field"),
+        }
+    }
+
+    #[test]
+    fn test_convert_to_inline_schema_ref_optional_wraps_nullable() {
         use vespera_core::schema::Reference;
         let schema = SchemaRef::Ref(Reference::schema("SomeType"));
         let result = convert_to_inline_schema(schema, true);
         match result {
             SchemaRef::Inline(s) => {
-                assert_eq!(s.schema_type, Some(SchemaType::Object));
+                assert_eq!(
+                    s.ref_path,
+                    Some("#/components/schemas/SomeType".to_string())
+                );
                 assert_eq!(s.nullable, Some(true));
             }
-            SchemaRef::Ref(_) => panic!("Expected Inline"),
+            SchemaRef::Ref(_) => panic!("Expected Inline wrapper for optional $ref"),
+        }
+    }
+
+    // ======== Enum query parameter tests ========
+
+    #[test]
+    fn test_query_struct_with_enum_field_produces_ref() {
+        // Enum field in a query struct should produce $ref to the enum schema
+        let mut struct_definitions = HashMap::new();
+        let mut known_schemas = HashSet::new();
+
+        struct_definitions.insert(
+            "FilterParams".to_string(),
+            r"
+            pub struct FilterParams {
+                pub status: Status,
+                pub page: i32,
+            }
+            "
+            .to_string(),
+        );
+
+        // Status is a known enum schema (registered via #[derive(Schema)])
+        // Its definition is an enum, so ItemStruct parsing will fail → $ref preserved
+        known_schemas.insert("Status".to_string());
+        struct_definitions.insert(
+            "Status".to_string(),
+            r"
+            pub enum Status {
+                Active,
+                Inactive,
+                Pending,
+            }
+            "
+            .to_string(),
+        );
+
+        let ty: Type = syn::parse_str("FilterParams").unwrap();
+        let result = parse_query_struct_to_parameters(&ty, &known_schemas, &struct_definitions);
+
+        assert!(result.is_some());
+        let params = result.unwrap();
+        assert_eq!(params.len(), 2);
+
+        // First param: status → $ref to enum schema
+        assert_eq!(params[0].name, "status");
+        assert_eq!(params[0].r#in, ParameterLocation::Query);
+        assert_eq!(params[0].required, Some(true));
+        match &params[0].schema {
+            Some(SchemaRef::Ref(r)) => {
+                assert_eq!(r.ref_path, "#/components/schemas/Status");
+            }
+            _ => panic!(
+                "Expected $ref for enum query parameter, got: {:?}",
+                params[0].schema
+            ),
+        }
+
+        // Second param: page → inline integer
+        assert_eq!(params[1].name, "page");
+        assert_eq!(params[1].required, Some(true));
+        match &params[1].schema {
+            Some(SchemaRef::Inline(s)) => {
+                assert_eq!(s.schema_type, Some(SchemaType::Integer));
+            }
+            _ => panic!("Expected inline integer schema"),
+        }
+    }
+
+    #[test]
+    fn test_query_struct_with_optional_enum_field() {
+        // Option<Enum> field → nullable $ref
+        let mut struct_definitions = HashMap::new();
+        let mut known_schemas = HashSet::new();
+
+        struct_definitions.insert(
+            "FilterParams".to_string(),
+            r"
+            pub struct FilterParams {
+                pub status: Option<Status>,
+            }
+            "
+            .to_string(),
+        );
+
+        known_schemas.insert("Status".to_string());
+        struct_definitions.insert(
+            "Status".to_string(),
+            r"
+            pub enum Status {
+                Active,
+                Inactive,
+            }
+            "
+            .to_string(),
+        );
+
+        let ty: Type = syn::parse_str("FilterParams").unwrap();
+        let result = parse_query_struct_to_parameters(&ty, &known_schemas, &struct_definitions);
+
+        assert!(result.is_some());
+        let params = result.unwrap();
+        assert_eq!(params.len(), 1);
+        assert_eq!(params[0].name, "status");
+        assert_eq!(params[0].required, Some(false));
+
+        // Option<Enum> → inline schema with ref_path + nullable
+        match &params[0].schema {
+            Some(SchemaRef::Inline(s)) => {
+                assert_eq!(s.ref_path, Some("#/components/schemas/Status".to_string()));
+                assert_eq!(s.nullable, Some(true));
+            }
+            _ => panic!("Expected inline schema with ref_path and nullable for Option<Enum>"),
         }
     }
 }
diff --git a/examples/axum-example/openapi.json b/examples/axum-example/openapi.json
index 0fa2c40..0ead67e 100644
--- a/examples/axum-example/openapi.json
+++ b/examples/axum-example/openapi.json
@@ -1304,6 +1304,36 @@
         }
       }
     },
+    "/terms": {
+      "get": {
+        "operationId": "list_terms",
+        "tags": [
+          "terms"
+        ],
+        "parameters": [
+          {
+            "name": "termsType",
+            "in": "query",
+            "required": true,
+            "schema": {
+              "$ref": "#/components/schemas/TermsType"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Successful response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/TermsQuery"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/test-struct": {
       "get": {
         "operationId": "mod_file_with_test_struct",
@@ -3300,6 +3330,24 @@
           "isSubscribed"
         ]
       },
+      "TermsQuery": {
+        "type": "object",
+        "properties": {
+          "termsType": {
+            "$ref": "#/components/schemas/TermsType"
+          }
+        },
+        "required": [
+          "termsType"
+        ]
+      },
+      "TermsType": {
+        "type": "string",
+        "enum": [
+          "terms",
+          "privacy"
+        ]
+      },
       "TestStruct": {
         "type": "object",
         "properties": {
@@ -3605,6 +3653,9 @@
     {
       "name": "hello"
     },
+    {
+      "name": "terms"
+    },
     {
       "name": "typed-form"
     },
diff --git a/examples/axum-example/src/routes/mod.rs b/examples/axum-example/src/routes/mod.rs
index 940a591..d1469c4 100644
--- a/examples/axum-example/src/routes/mod.rs
+++ b/examples/axum-example/src/routes/mod.rs
@@ -1,6 +1,7 @@
 use std::collections::HashMap;
 
-use serde::Deserialize;
+use sea_orm::{DeriveActiveEnum, EnumIter};
+use serde::{Deserialize, Serialize};
 use vespera::{
     Schema,
     axum::{Json, extract::Query},
@@ -170,3 +171,25 @@ pub async fn mod_file_with_complex_struct_body_with_rename(
 pub async fn mod_file_with_test_struct(Query(query): Query<TestStruct>) -> Json<TestStruct> {
     Json(query)
 }
+#[derive(
+    Debug, Clone, PartialEq, Eq, EnumIter, DeriveActiveEnum, Serialize, Deserialize, vespera::Schema,
+)]
+#[serde(rename_all = "camelCase")]
+#[sea_orm(rs_type = "String", db_type = "Enum", enum_name = "terms_terms_type")]
+pub enum TermsType {
+    #[sea_orm(string_value = "terms")]
+    Terms,
+    #[sea_orm(string_value = "privacy")]
+    Privacy,
+}
+
+#[derive(Debug, Serialize, Deserialize, Schema)]
+#[serde(rename_all = "camelCase")]
+pub struct TermsQuery {
+    pub terms_type: TermsType,
+}
+
+#[vespera::route(get, path = "/terms", tags = ["terms"])]
+pub async fn list_terms(Query(query): Query<TermsQuery>) -> Json<TermsQuery> {
+    Json(query)
+}
diff --git a/examples/axum-example/tests/snapshots/integration_test__openapi.snap b/examples/axum-example/tests/snapshots/integration_test__openapi.snap
index ca8c936..5fce0eb 100644
--- a/examples/axum-example/tests/snapshots/integration_test__openapi.snap
+++ b/examples/axum-example/tests/snapshots/integration_test__openapi.snap
@@ -1308,6 +1308,36 @@ expression: "std::fs::read_to_string(\"openapi.json\").unwrap()"
         }
       }
     },
+    "/terms": {
+      "get": {
+        "operationId": "list_terms",
+        "tags": [
+          "terms"
+        ],
+        "parameters": [
+          {
+            "name": "termsType",
+            "in": "query",
+            "required": true,
+            "schema": {
+              "$ref": "#/components/schemas/TermsType"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Successful response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/TermsQuery"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/test-struct": {
       "get": {
         "operationId": "mod_file_with_test_struct",
@@ -3304,6 +3334,24 @@ expression: "std::fs::read_to_string(\"openapi.json\").unwrap()"
           "isSubscribed"
         ]
       },
+      "TermsQuery": {
+        "type": "object",
+        "properties": {
+          "termsType": {
+            "$ref": "#/components/schemas/TermsType"
+          }
+        },
+        "required": [
+          "termsType"
+        ]
+      },
+      "TermsType": {
+        "type": "string",
+        "enum": [
+          "terms",
+          "privacy"
+        ]
+      },
       "TestStruct": {
         "type": "object",
         "properties": {
@@ -3609,6 +3657,9 @@ expression: "std::fs::read_to_string(\"openapi.json\").unwrap()"
     {
       "name": "hello"
     },
+    {
+      "name": "terms"
+    },
     {
       "name": "typed-form"
     },
diff --git a/openapi.json b/openapi.json
index 0fa2c40..0ead67e 100644
--- a/openapi.json
+++ b/openapi.json
@@ -1304,6 +1304,36 @@
         }
       }
     },
+    "/terms": {
+      "get": {
+        "operationId": "list_terms",
+        "tags": [
+          "terms"
+        ],
+        "parameters": [
+          {
+            "name": "termsType",
+            "in": "query",
+            "required": true,
+            "schema": {
+              "$ref": "#/components/schemas/TermsType"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Successful response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/TermsQuery"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/test-struct": {
       "get": {
         "operationId": "mod_file_with_test_struct",
@@ -3300,6 +3330,24 @@
           "isSubscribed"
         ]
       },
+      "TermsQuery": {
+        "type": "object",
+        "properties": {
+          "termsType": {
+            "$ref": "#/components/schemas/TermsType"
+          }
+        },
+        "required": [
+          "termsType"
+        ]
+      },
+      "TermsType": {
+        "type": "string",
+        "enum": [
+          "terms",
+          "privacy"
+        ]
+      },
       "TestStruct": {
         "type": "object",
         "properties": {
@@ -3605,6 +3653,9 @@
     {
       "name": "hello"
     },
+    {
+      "name": "terms"
+    },
     {
       "name": "typed-form"
     },