diff --git a/src/generators/clean-arch.generator.ts b/src/generators/clean-arch.generator.ts
index 747dd2d..d7e8fb3 100644
--- a/src/generators/clean-arch.generator.ts
+++ b/src/generators/clean-arch.generator.ts
@@ -3,7 +3,7 @@ import path from 'path';
 import mustache from 'mustache';
 import { logStep, logSuccess, logDetail } from '../utils/logger';
 import { mapSwaggerTypeToTs } from '../utils/type-mapper';
-import { toCamelCase } from '../utils/name-formatter';
+import { toCamelCase, toPascalCase } from '../utils/name-formatter';
 import { resolveMockValue } from '../utils/mock-value-resolver';
 import type {
   SwaggerAnalysis,
@@ -362,7 +362,7 @@ export function generateCleanArchitecture(
         apis: [
           {
             operations: {
-              classname: tag,
+              classname: toPascalCase(tag),
               classFilename: toCamelCase(tag),
               classVarName: toCamelCase(tag),
               constantName: tag.toUpperCase().replace(/[^A-Z0-9]/g, '_'),
diff --git a/src/utils/name-formatter.ts b/src/utils/name-formatter.ts
index c6ff94b..32ad139 100644
--- a/src/utils/name-formatter.ts
+++ b/src/utils/name-formatter.ts
@@ -1,12 +1,31 @@
 /**
- * Converts a PascalCase name to camelCase by lowercasing the first character.
+ * Converts a string to PascalCase, handling spaces, hyphens and underscores.
+ * Used to derive class names from schema/tag names.
+ *
+ * @example
+ * toPascalCase('Product Format')  // 'ProductFormat'
+ * toPascalCase('user-response')   // 'UserResponse'
+ * toPascalCase('UserSchema')      // 'UserSchema'
+ */
+export function toPascalCase(name: string): string {
+  if (!name) return name;
+  return name
+    .split(/[\s\-_]+/)
+    .map((word) => word.charAt(0).toUpperCase() + word.slice(1))
+    .join('');
+}
+
+/**
+ * Converts a string to camelCase, handling spaces, hyphens and underscores.
  * Used to derive class filenames and variable names from schema/tag names.
  *
  * @example
+ * toCamelCase('Product Format')  // 'productFormat'
  * toCamelCase('ProductResponse') // 'productResponse'
  * toCamelCase('UserSchema')      // 'userSchema'
  */
 export function toCamelCase(name: string): string {
   if (!name) return name;
-  return name.charAt(0).toLowerCase() + name.slice(1);
+  const pascal = toPascalCase(name);
+  return pascal.charAt(0).toLowerCase() + pascal.slice(1);
 }