'components' => [
 'user' => [ 
 'identityClass' => 'common\models\User',
 'enableAutoLogin' => true,
 'enableSession' => false,
 ],
 'urlManager' => [
 'enablePrettyUrl' => true,
 'showScriptName' => false,
 'enableStrictParsing' => true,
 'rules' => [
  [
  'class' => 'yii\rest\UrlRule',
  'controller' => ['v1/user'],
  'extraPatterns' => [
   'POST login' => 'login',
   'GET signup-test' => 'signup-test',
  ]
  ],
 ]
 ],
 // ......
],

use yii\filters\auth\QueryParamAuth;

public function behaviors() 
{
 return ArrayHelper::merge (parent::behaviors(), [ 
  'authenticator' => [ 
  'class' => QueryParamAuth::className() 
  ] 
 ] );
}

public function behaviors() 
{
 return ArrayHelper::merge (parent::behaviors(), [ 
  'authenticator' => [ 
  'class' => QueryParamAuth::className(),
  'optional' => [
   'login',
   'signup-test'
  ],
  ] 
 ] );
}

use common\models\User;
/**
 * 添加测试用户
 */
public function actionSignupTest ()
{
 $user = new User();
 $user->generateAuthKey();
 $user->setPassword('123456');
 $user->username = '111';
 $user->email = '111@111.com';
 $user->save(false);

 return [
 'code' => 0
 ];
}

/**
 * 登录
 */
public function actionLogin ()
{
 $model = new LoginForm;
 $model->setAttributes(Yii::$app->request->post());
 if ($user = $model->login()) {
 if ($user instanceof IdentityInterface) {
  return $user->api_token;
 } else {
  return $user->errors;
 }
 } else {
 return $model->errors;
 }
}

<?php
namespace api\models;

use Yii;
use yii\base\Model;
use common\models\User;

/**
 * Login form
 */
class LoginForm extends Model
{
 public $username;
 public $password;

 private $_user;

 const GET_API_TOKEN = 'generate_api_token';

 public function init ()
 {
 parent::init();
 $this->on(self::GET_API_TOKEN, [$this, 'onGenerateApiToken']);
 }


 /**
 * @inheritdoc
 * 对客户端表单数据进行验证的rule
 */
 public function rules()
 {
 return [
  [['username', 'password'], 'required'],
  ['password', 'validatePassword'],
 ];
 }

 /**
 * 自定义的密码认证方法
 */
 public function validatePassword($attribute, $params)
 {
 if (!$this->hasErrors()) {
  $this->_user = $this->getUser();
  if (!$this->_user || !$this->_user->validatePassword($this->password)) {
  $this->addError($attribute, '用户名或密码错误.');
  }
 }
 }
 /**
 * @inheritdoc
 */
 public function attributeLabels()
 {
 return [
  'username' => '用户名',
  'password' => '密码',
 ];
 }
 /**
 * Logs in a user using the provided username and password.
 *
 * @return boolean whether the user is logged in successfully
 */
 public function login()
 {
 if ($this->validate()) {
  $this->trigger(self::GET_API_TOKEN);
  return $this->_user;
 } else {
  return null;
 }
 }

 /**
 * 根据用户名获取用户的认证信息
 *
 * @return User|null
 */
 protected function getUser()
 {
 if ($this->_user === null) {
  $this->_user = User::findByUsername($this->username);
 }

 return $this->_user;
 }

 /**
 * 登录校验成功后，为用户生成新的token
 * 如果token失效，则重新生成token
 */
 public function onGenerateApiToken ()
 {
 if (!User::apiTokenIsValid($this->_user->api_token)) {
  $this->_user->generateApiToken();
  $this->_user->save(false);
 }
 }
}

/**
 * 生成 api_token
 */
public function generateApiToken()
{
 $this->api_token = Yii::$app->security->generateRandomString() . '_' . time();
}

/**
 * 校验api_token是否有效
 */
public static function apiTokenIsValid($token)
{
 if (empty($token)) {
 return false;
 }

 $timestamp = (int) substr($token, strrpos($token, '_') + 1);
 $expire = Yii::$app->params['user.apiTokenExpire'];
 return $timestamp + $expire >= time();
}

<?php
return [
 // ...
 // token 有效期默认1天
 'user.apiTokenExpire' => 1*24*3600,
];

public function behaviors() 
{
 return ArrayHelper::merge (parent::behaviors(), [ 
   'authenticator' => [ 
    'class' => QueryParamAuth::className(),
    'tokenParam' => 'token',
    'optional' => [
     'login',
     'signup-test'
    ],
   ] 
 ] );
}

'extraPatterns' => [
 'POST login' => 'login',
 'GET signup-test' => 'signup-test',
 'GET user-profile' => 'user-profile',
]

public static function findIdentityByAccessToken($token, $type = null)
{
 // 如果token无效的话，
 if(!static::apiTokenIsValid($token)) {
  throw new \yii\web\UnauthorizedHttpException("token is invalid.");
 }

 return static::findOne(['api_token' => $token, 'status' => self::STATUS_ACTIVE]);
 // throw new NotSupportedException('"findIdentityByAccessToken" is not implemented.');
}

/**
 * 获取用户信息
 */
public function actionUserProfile ($token)
{
 // 到这一步，token都认为是有效的了
 // 下面只需要实现业务逻辑即可，下面仅仅作为案例，比如你可能需要关联其他表获取用户信息等等
 $user = User::findIdentityByAccessToken($token);
 return [
  'id' => $user->id,
  'username' => $user->username,
  'email' => $user->email,
 ];
}

'response' => [
 'class' => 'yii\web\Response',
 'on beforeSend' => function ($event) {
  $response = $event->sender;
  $response->format = yii\web\Response::FORMAT_JSON;
 },
],

yii\web\BadRequestHttpException
yii\web\ForbiddenHttpException
yii\web\NotFoundHttpException
yii\web\ServerErrorHttpException
yii\web\UnauthorizedHttpException
yii\web\TooManyRequestsHttpException

'response' => [
 'class' => 'yii\web\Response',
 'on beforeSend' => function ($event) {
  $response = $event->sender;
  $response->data = [
   'code' => $response->getStatusCode(),
   'data' => $response->data,
   'message' => $response->statusText
  ];
  $response->format = yii\web\Response::FORMAT_JSON;
 },
],