diff --git a/src/config/swagger.config.spec.ts b/src/config/swagger.config.spec.ts
new file mode 100644
index 0000000..b5e5324
--- /dev/null
+++ b/src/config/swagger.config.spec.ts
@@ -0,0 +1,12 @@
+import { createSwaggerConfig } from './swagger.config';
+
+describe('createSwaggerConfig', () => {
+  // Regression test for issue #104: Swagger UI returned "Unauthorized" because the
+  // X-API-Key scheme was defined but never applied — no operation declared a security
+  // requirement, so Swagger UI never sent the key. The fix applies it globally.
+  it('applies the X-API-Key security scheme as a global requirement', () => {
+    const config = createSwaggerConfig();
+
+    expect(config.security).toContainEqual({ 'X-API-Key': [] });
+  });
+});
diff --git a/src/config/swagger.config.ts b/src/config/swagger.config.ts
new file mode 100644
index 0000000..db379f6
--- /dev/null
+++ b/src/config/swagger.config.ts
@@ -0,0 +1,32 @@
+import { DocumentBuilder, OpenAPIObject } from '@nestjs/swagger';
+
+/**
+ * Security scheme name for the API key, used both when defining the scheme and
+ * when applying it as a global requirement so Swagger UI sends the header.
+ */
+export const API_KEY_SECURITY_SCHEME = 'X-API-Key';
+
+/**
+ * Builds the OpenAPI document configuration for the OpenWA API.
+ */
+export function createSwaggerConfig(): Omit<OpenAPIObject, 'paths'> {
+  return (
+    new DocumentBuilder()
+      .setTitle('OpenWA API')
+      .setDescription('Open Source WhatsApp API Gateway - Free, Self-Hosted HTTP API')
+      .setVersion('0.1.6')
+      .addApiKey({ type: 'apiKey', name: 'X-API-Key', in: 'header' }, API_KEY_SECURITY_SCHEME)
+      // Apply the scheme globally so Swagger UI sends the key with every request
+      // (mirrors the global ApiKeyGuard). Without this, "Authorize" is cosmetic.
+      .addSecurityRequirements(API_KEY_SECURITY_SCHEME)
+      .addTag('sessions', 'WhatsApp session management')
+      .addTag('messages', 'Send and manage messages')
+      .addTag('webhooks', 'Webhook configuration')
+      .addTag('contacts', 'Contact management')
+      .addTag('groups', 'Group management')
+      .addTag('labels', 'Label management (WhatsApp Business)')
+      .addTag('channels', 'Channel/Newsletter management')
+      .addTag('health', 'Health check endpoints')
+      .build()
+  );
+}
diff --git a/src/main.ts b/src/main.ts
index 61966fb..d598990 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,9 +1,10 @@
 import { NestFactory } from '@nestjs/core';
 import { ValidationPipe } from '@nestjs/common';
-import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
+import { SwaggerModule } from '@nestjs/swagger';
 import helmet from 'helmet';
 import { AppModule } from './app.module';
 import { ShutdownService } from './common/services/shutdown.service';
+import { createSwaggerConfig } from './config/swagger.config';
 import * as dotenv from 'dotenv';
 import * as fs from 'fs';
 import * as path from 'path';
@@ -141,20 +142,7 @@ async function bootstrap() {
   );
 
   // Swagger documentation
-  const config = new DocumentBuilder()
-    .setTitle('OpenWA API')
-    .setDescription('Open Source WhatsApp API Gateway - Free, Self-Hosted HTTP API')
-    .setVersion('0.1.6')
-    .addApiKey({ type: 'apiKey', name: 'X-API-Key', in: 'header' }, 'X-API-Key')
-    .addTag('sessions', 'WhatsApp session management')
-    .addTag('messages', 'Send and manage messages')
-    .addTag('webhooks', 'Webhook configuration')
-    .addTag('contacts', 'Contact management')
-    .addTag('groups', 'Group management')
-    .addTag('labels', 'Label management (WhatsApp Business)')
-    .addTag('channels', 'Channel/Newsletter management')
-    .addTag('health', 'Health check endpoints')
-    .build();
+  const config = createSwaggerConfig();
 
   const document = SwaggerModule.createDocument(app, config);
   SwaggerModule.setup('api/docs', app, document);
diff --git a/src/modules/auth/auth.controller.ts b/src/modules/auth/auth.controller.ts
index 3d723f3..dc15780 100644
--- a/src/modules/auth/auth.controller.ts
+++ b/src/modules/auth/auth.controller.ts
@@ -1,12 +1,11 @@
 import { Controller, Get, Post, Put, Delete, Body, Param, HttpCode, HttpStatus } from '@nestjs/common';
-import { ApiTags, ApiOperation, ApiResponse, ApiBearerAuth } from '@nestjs/swagger';
+import { ApiTags, ApiOperation, ApiResponse } from '@nestjs/swagger';
 import { AuthService } from './auth.service';
 import { CreateApiKeyDto, UpdateApiKeyDto, ApiKeyResponseDto, ApiKeyCreatedResponseDto } from './dto';
 import { RequireRole } from './decorators/auth.decorators';
 import { ApiKeyRole } from './entities/api-key.entity';
 
 @ApiTags('auth')
-@ApiBearerAuth()
 @Controller('auth/api-keys')
 export class AuthController {
   constructor(private readonly authService: AuthService) {}
diff --git a/src/modules/catalog/catalog.controller.ts b/src/modules/catalog/catalog.controller.ts
index 5fece45..d2ecf98 100644
--- a/src/modules/catalog/catalog.controller.ts
+++ b/src/modules/catalog/catalog.controller.ts
@@ -1,10 +1,9 @@
 import { Controller, Get, Post, Param, Body, Query } from '@nestjs/common';
-import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
+import { ApiTags, ApiOperation } from '@nestjs/swagger';
 import { CatalogService } from './catalog.service';
 import { SendProductDto, SendCatalogDto, ProductQueryDto } from './dto/send-product.dto';
 
 @ApiTags('Catalog')
-@ApiBearerAuth()
 @Controller('sessions/:sessionId')
 export class CatalogController {
   constructor(private readonly catalogService: CatalogService) {}
diff --git a/src/modules/plugins/plugins.controller.ts b/src/modules/plugins/plugins.controller.ts
index 870bcce..4792fec 100644
--- a/src/modules/plugins/plugins.controller.ts
+++ b/src/modules/plugins/plugins.controller.ts
@@ -1,10 +1,9 @@
 import { Controller, Get, Post, Put, Param, Body, HttpCode, HttpStatus } from '@nestjs/common';
-import { ApiTags, ApiOperation, ApiResponse, ApiBearerAuth } from '@nestjs/swagger';
+import { ApiTags, ApiOperation, ApiResponse } from '@nestjs/swagger';
 import { PluginsService } from './plugins.service';
 import { PluginDto, PluginConfigDto } from './dto/plugin.dto';
 
 @ApiTags('plugins')
-@ApiBearerAuth()
 @Controller('plugins')
 export class PluginsController {
   constructor(private readonly pluginsService: PluginsService) {}
diff --git a/src/modules/stats/stats.controller.ts b/src/modules/stats/stats.controller.ts
index 803e507..edde544 100644
--- a/src/modules/stats/stats.controller.ts
+++ b/src/modules/stats/stats.controller.ts
@@ -1,10 +1,9 @@
 import { Controller, Get, Param, Query } from '@nestjs/common';
-import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
+import { ApiTags, ApiOperation } from '@nestjs/swagger';
 import { StatsService } from './stats.service';
 import { StatsQueryDto } from './dto/stats-query.dto';
 
 @ApiTags('Statistics')
-@ApiBearerAuth()
 @Controller('stats')
 export class StatsController {
   constructor(private readonly statsService: StatsService) {}
diff --git a/src/modules/status/status.controller.ts b/src/modules/status/status.controller.ts
index 34574b1..5840695 100644
--- a/src/modules/status/status.controller.ts
+++ b/src/modules/status/status.controller.ts
@@ -1,11 +1,10 @@
 import { Controller, Get, Post, Delete, Param, Body } from '@nestjs/common';
-import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
+import { ApiTags, ApiOperation } from '@nestjs/swagger';
 import { StatusService } from './status.service';
 import { SendTextStatusDto } from './dto/send-text-status.dto';
 import { SendImageStatusDto, SendVideoStatusDto } from './dto/send-media-status.dto';
 
 @ApiTags('Status')
-@ApiBearerAuth()
 @Controller('sessions/:sessionId/status')
 export class StatusController {
   constructor(private readonly statusService: StatusService) {}