diff --git a/src/auth/auth.controller.ts b/src/auth/auth.controller.ts
index c5b8d41..e6a326c 100644
--- a/src/auth/auth.controller.ts
+++ b/src/auth/auth.controller.ts
@@ -1,4 +1,7 @@
-import { Body, Controller, Get, Post, UseGuards } from '@nestjs/common';
+/**
+ * 登录鉴权 HTTP 入口，负责校验入参并把请求上下文传给审计链路。
+ */
+import { Body, Controller, Get, Post, Req, UseGuards } from '@nestjs/common';
 import {
   ApiBody,
   ApiCreatedResponse,
@@ -20,7 +23,13 @@ import {
 } from './auth.dto';
 import { AuthService } from './auth.service';
 import { CurrentUser } from './current-user.decorator';
-import { AuthenticatedUser, LoginResult } from './auth.types';
+import {
+  AuthenticatedUser,
+  AuthRequestContext,
+  LoginResult,
+  RequestWithUser,
+} from './auth.types';
+import { resolveRequestId } from '../common/http/request-id';
 
 @ApiTags('登录鉴权')
 @Controller('auth')
@@ -31,9 +40,10 @@ export class AuthController {
   @ApiBody({ type: LoginDto })
   @ApiCreatedResponse({ description: '登录成功，返回登录令牌和当前账号信息。' })
   async login(
+    @Req() request: RequestWithUser,
     @Body(new ZodValidationPipe(loginSchema)) body: LoginInput,
   ): Promise<LoginResult> {
-    return this.authService.login(body);
+    return this.authService.login(body, this.auditContextFor(request));
   }
 
   @Get('me')
@@ -75,4 +85,14 @@ export class AuthController {
       message: '已退出登录',
     };
   }
+
+  private auditContextFor(request: RequestWithUser): AuthRequestContext {
+    const userAgent = request.headers['user-agent'];
+
+    return {
+      requestId: resolveRequestId(request.headers),
+      sourceIp: request.ip ?? request.socket?.remoteAddress,
+      userAgent: Array.isArray(userAgent) ? userAgent[0] : userAgent,
+    };
+  }
 }
diff --git a/src/auth/auth.service.ts b/src/auth/auth.service.ts
index 2b396ac..df5aa7a 100644
--- a/src/auth/auth.service.ts
+++ b/src/auth/auth.service.ts
@@ -1,3 +1,6 @@
+/**
+ * 登录、密码和项目权限服务，统一维护账号状态与鉴权审计。
+ */
 import { Injectable, OnModuleInit } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
 import { AuditService } from '../audit/audit.service';
@@ -15,6 +18,7 @@ import {
   LoginInput,
 } from './auth.dto';
 import {
+  AuthRequestContext,
   AuthenticatedUser,
   LoginResult,
   ProjectPermissionLevel,
@@ -41,14 +45,19 @@ export class AuthService implements OnModuleInit {
     await this.userRepository.ensureSuperAdmin(passwordHash);
   }
 
-  async login(input: LoginInput): Promise<LoginResult> {
+  async login(
+    input: LoginInput,
+    context: AuthRequestContext = {},
+  ): Promise<LoginResult> {
     const user = await this.userRepository.findByAccount(input.account);
 
     if (!user) {
+      await this.recordLoginFailure(input.account, 'account_not_found', context);
       throw new AppError('AUTH_REQUIRED', '账号或密码错误', 401);
     }
 
     if (user.status !== 'active') {
+      await this.recordLoginFailure(input.account, 'disabled', context, user);
       throw new AppError('FORBIDDEN', '账号已被禁用，请联系超级管理员', 403);
     }
 
@@ -58,6 +67,7 @@ export class AuthService implements OnModuleInit {
     );
 
     if (!passwordMatched) {
+      await this.recordLoginFailure(input.account, 'invalid_password', context, user);
       throw new AppError('AUTH_REQUIRED', '账号或密码错误', 401);
     }
 
@@ -68,6 +78,9 @@ export class AuthService implements OnModuleInit {
       resourceId: user.id,
       actorId: user.id,
       actorName: user.account,
+      requestId: context.requestId,
+      sourceIp: context.sourceIp,
+      userAgent: context.userAgent,
       after: {
         role: user.role,
         mustChangePassword: user.mustChangePassword,
@@ -230,6 +243,32 @@ export class AuthService implements OnModuleInit {
     return user;
   }
 
+  private async recordLoginFailure(
+    account: string,
+    reason: 'account_not_found' | 'disabled' | 'invalid_password',
+    context: AuthRequestContext,
+    user?: UserRecord,
+  ): Promise<void> {
+    await this.auditService.record({
+      action: 'USER_LOGIN_FAILED',
+      resourceType: 'user',
+      resourceId: user?.id,
+      actorId: user?.id,
+      actorName: user?.account ?? account.trim(),
+      requestId: context.requestId,
+      sourceIp: context.sourceIp,
+      userAgent: context.userAgent,
+      after: {
+        reason,
+        role: user?.role,
+        status: user?.status,
+      },
+      parameterDigest: {
+        account: account.trim(),
+      },
+    });
+  }
+
   private resolveSuperAdminInitialPassword(): string {
     const password = this.config.get('SUPER_ADMIN_INITIAL_PASSWORD', {
       infer: true,
diff --git a/src/auth/auth.types.ts b/src/auth/auth.types.ts
index f62459a..70d1aff 100644
--- a/src/auth/auth.types.ts
+++ b/src/auth/auth.types.ts
@@ -1,3 +1,6 @@
+/**
+ * 登录鉴权模块的账号、权限和请求上下文类型。
+ */
 export type AuthRole = 'super_admin' | 'member';
 
 export type AuthStatus = 'active' | 'disabled';
@@ -51,7 +54,17 @@ export type LoginResult = {
   expiresAt: string;
 };
 
+export type AuthRequestContext = {
+  requestId?: string;
+  sourceIp?: string;
+  userAgent?: string;
+};
+
 export type RequestWithUser = {
   headers: Record<string, string | string[] | undefined>;
+  ip?: string;
+  socket?: {
+    remoteAddress?: string;
+  };
   user?: AuthenticatedUser;
 };