diff --git a/docs/fastapi.md b/docs/fastapi.md
deleted file mode 100644
index 8c20ac7..0000000
--- a/docs/fastapi.md
+++ /dev/null
@@ -1,46 +0,0 @@
-提供的实用程序可简化 FastAPI 中 OAuth2 流程的集成
-
-## `FastAPIOAuth20`
-
-依赖关系可调用，用于处理授权回调，它读取查询参数并返回访问令牌和状态
-
-```python
-from fastapi import FastAPI, Depends
-from fastapi_oauth20 import FastAPIOAuth20, LinuxDoOAuth20
-
-client = LinuxDoOAuth20("CLIENT_ID", "CLIENT_SECRET")
-linuxdo_oauth2_callback = FastAPIOAuth20(client, "oauth2-callback")
-
-app = FastAPI()
-
-
-@app.get("/oauth2-callback", name="oauth-callback")
-async def oauth2_callback(access_token_state=Depends(linuxdo_oauth2_callback)):
-    token, state = access_token_state
-    # Do something useful
-```
-
-## 自定义异常
-
-如果回调逻辑内部发生错误（用户拒绝访问、授权代码无效......），依赖关系将引发 `OAuth20AuthorizeCallbackError` 错误
-
-它继承自 FastAPI 的 [HTTPException](https://fastapi.tiangolo.com/reference/exceptions/#fastapi.HTTPException)，因此默认的
-FastAPI 异常处理程序会自动对其进行处理。您可以通过为 `OAuth20AuthorizeCallbackError` 实现自己的异常处理程序来自定义此行为
-
-```python
-from fastapi import FastAPI, Request
-from fastapi.responses import JSONResponse
-from fastapi_oauth20.callback import OAuth20AuthorizeCallbackError
-
-app = FastAPI()
-
-
-@app.exception_handler(OAuth20AuthorizeCallbackError)
-async def oauth2_authorize_callback_error_handler(request: Request, exc: OAuth20AuthorizeCallbackError):
-    detail = exc.detail
-    status_code = exc.status_code
-    return JSONResponse(
-        status_code=status_code,
-        content={"message": "The OAuth2 callback failed", "detail": detail},
-    )
-```
diff --git a/docs/usage.md b/docs/usage.md
index 9ac34ad..4a95f3a 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -1,3 +1,5 @@
+from fastapi_oauth20 import FastAPIOAuth20
+
 # 使用指南
 
 本指南介绍如何将 FastAPI OAuth2.0 库与各种 OAuth2 提供程序一起使用。
@@ -19,12 +21,6 @@ github_client = GitHubOAuth20(
     client_id="your_github_client_id",
     client_secret="your_github_client_secret"
 )
-
-# 初始化 Google OAuth2 客户端
-google_client = GoogleOAuth20(
-    client_id="your_google_client_id",
-    client_secret="your_google_client_secret"
-)
 ```
 
 ### 2. 创建 FastAPI OAuth2 依赖
@@ -35,35 +31,22 @@ github_oauth = FastAPIOAuth20(
     client=github_client,
     redirect_uri="http://localhost:8000/auth/github/callback"
 )
-
-google_oauth = FastAPIOAuth20(
-    client=google_client,
-    redirect_uri="http://localhost:8000/auth/google/callback"
-)
 ```
 
 ### 3. 定义授权端点
 
 ```python
-@app.get("/auth/{provider}")
-async def auth_provider(provider: str):
+@app.get("/oauth2/github")
+async def oauth2_github():
     """重定向用户到 OAuth2 提供商进行授权"""
 
     # 生成安全的 state 参数用于 CSRF 保护
     state = secrets.token_urlsafe(32)
 
-    if provider == "github":
-        auth_url = await github_client.get_authorization_url(
-            redirect_uri="http://localhost:8000/auth/github/callback",
-            state=state
-        )
-    elif provider == "google":
-        auth_url = await google_client.get_authorization_url(
-            redirect_uri="http://localhost:8000/auth/google/callback",
-            state=state
-        )
-    else:
-        raise HTTPException(status_code=404, detail="不支持的提供商")
+    auth_url = await github_client.get_authorization_url(
+        redirect_uri="http://localhost:8000/auth/github/callback",
+        state=state
+    )
 
     return RedirectResponse(url=auth_url)
 ```
@@ -71,12 +54,9 @@ async def auth_provider(provider: str):
 ### 4. 处理 OAuth 回调
 
 ```python
-from typing import Tuple, Dict, Any
-
-
-@app.get("/auth/github/callback")
-async def github_callback(
-        oauth_result: Tuple[Dict[str, Any], str] = Depends(github_oauth)
+@app.get("/oauth2/github/callback")
+async def oauth2_github_callback(
+    oauth_result: Annotated[FastAPIOAuth20, Depends(github_oauth)]
 ):
     """处理 GitHub OAuth 回调"""
     token_data, state = oauth_result
@@ -89,142 +69,73 @@ async def github_callback(
         "access_token": token_data["access_token"],
         "state": state
     }
-
-
-@app.get("/auth/google/callback")
-async def google_callback(
-        oauth_result: Tuple[Dict[str, Any], str] = Depends(google_oauth)
-):
-    """处理 Google OAuth 回调"""
-    token_data, state = oauth_result
-
-    # 获取用户信息
-    user_info = await google_client.get_userinfo(token_data["access_token"])
-
-    return {
-        "user": user_info,
-        "access_token": token_data["access_token"],
-        "state": state
-    }
 ```
 
-## 高级用法
-
-### PKCE (Proof Key for Code Exchange)
-
-对于公共客户端（移动应用、SPA），使用 PKCE 增强安全性：
-
-```python
-import base64
-import hashlib
-import secrets
-
-
-def generate_pkce_challenge():
-    """生成 PKCE 代码验证器和挑战码"""
-    code_verifier = base64.urlsafe_b64encode(secrets.token_bytes(32)).decode('utf-8').rstrip('=')
-    code_challenge = base64.urlsafe_b64encode(
-        hashlib.sha256(code_verifier.encode('utf-8')).digest()
-    ).decode('utf-8').rstrip('=')
-    return code_verifier, code_challenge
-
-
-@app.get("/auth/github/pkce")
-async def github_auth_pkce():
-    """GitHub OAuth with PKCE"""
-    code_verifier, code_challenge = generate_pkce_challenge()
-    state = secrets.token_urlsafe(32)
-
-    # 在实际应用中，应该将 code_verifier 和 state 存储在会话或数据库中
-    # 这里为了演示目的简化处理
-
-    auth_url = await github_client.get_authorization_url(
-        redirect_uri="http://localhost:8000/auth/github/callback",
-        state=state,
-        code_challenge=code_challenge,
-        code_challenge_method="S256"
-    )
-
-    return RedirectResponse(url=auth_url)
-```
-
-### 令牌刷新
+## 令牌刷新
 
 某些提供商支持刷新令牌来延长会话：
 
 ```python
-@app.post("/auth/refresh")
-async def refresh_token(refresh_token: str, provider: str):
+@app.post("/oauth2/refresh")
+async def oauth2_refresh_token(refresh_token: str):
     """使用刷新令牌获取新的访问令牌"""
-
-    if provider == "github":
-        # GitHub 不支持 OAuth 刷新令牌
-        raise HTTPException(status_code=400, detail="GitHub 不支持令牌刷新")
-    elif provider == "google":
-        try:
-            new_tokens = await google_client.refresh_token(refresh_token)
-            return {"access_token": new_tokens["access_token"]}
-        except Exception as e:
-            raise HTTPException(status_code=400, detail=str(e))
+    try:
+        new_tokens = await google_client.refresh_token(refresh_token)
+        return {"access_token": new_tokens["access_token"]}
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=str(e))
 ```
 
-### 令牌撤销
+## 令牌撤销
 
 用户登出时撤销令牌：
 
 ```python
-@app.post("/auth/revoke")
-async def revoke_token(access_token: str, provider: str):
+@app.post("/oauth2/revoke")
+async def oauth2_revoke_token(access_token: str):
     """撤销访问令牌"""
-
-    if provider == "google":
-        try:
-            await google_client.revoke_token(access_token)
-            return {"message": "令牌撤销成功"}
-        except Exception as e:
-            raise HTTPException(status_code=400, detail=str(e))
-    else:
-        raise HTTPException(status_code=400, detail="该提供商不支持令牌撤销")
+    try:
+        await google_client.revoke_token(access_token)
+        return {"message": "令牌撤销成功"}
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=str(e))
 ```
 
 ## 错误处理
 
-库提供了全面的错误处理：
+如果回调逻辑内部发生错误（用户拒绝访问、授权代码无效......），依赖关系将引发 `OAuth20AuthorizeCallbackError` 错误
 
-```python
-from fastapi_oauth20.errors import (
-    OAuth20AuthorizeCallbackError,
-    AccessTokenError,
-    GetUserInfoError
-)
+它继承自 FastAPI 的 [HTTPException](https://fastapi.tiangolo.com/reference/exceptions/#fastapi.HTTPException)，因此默认的
+FastAPI 异常处理程序会自动对其进行处理。您可以通过为 `OAuth20AuthorizeCallbackError` 实现自己的异常处理程序来自定义此行为
 
+```python
+from fastapi import FastAPI, Request
+from fastapi.responses import JSONResponse
+from fastapi_oauth20 import OAuth20AuthorizeCallbackError
 
-@app.exception_handler(OAuth20AuthorizeCallbackError)
-async def oauth_callback_error_handler(request: Request, exc: OAuth20AuthorizeCallbackError):
-    """处理 OAuth 回调错误"""
-    return {
-        "error": "OAuth 授权失败",
-        "detail": exc.detail,
-        "status_code": exc.status_code
-    }
+app = FastAPI()
 
 
-@app.exception_handler(AccessTokenError)
-async def access_token_error_handler(request: Request, exc: AccessTokenError):
-    """处理访问令牌错误"""
-    return {
-        "error": "访问令牌交换失败",
-        "detail": exc.msg
-    }
+@app.exception_handler(OAuth20AuthorizeCallbackError)
+async def oauth2_authorize_callback_error_handler(request: Request, exc: OAuth20AuthorizeCallbackError):
+    detail = exc.detail
+    status_code = exc.status_code
+    return JSONResponse(
+        status_code=status_code,
+        content={"message": "The OAuth2 callback failed", "detail": detail},
+    )
 ```
 
 ## 完整示例
 
 ```python
+from typing import Annotated
+
 from fastapi import FastAPI, Depends, HTTPException
 from fastapi.responses import RedirectResponse
 from fastapi_oauth20 import GitHubOAuth20, FastAPIOAuth20
-from fastapi_oauth20.errors import OAuth20AuthorizeCallbackError
+from fastapi_oauth20 import OAuth20AuthorizeCallbackError
+
 import secrets
 
 app = FastAPI()
@@ -242,8 +153,8 @@ github_oauth = FastAPIOAuth20(
 )
 
 
-@app.get("/auth/github")
-async def github_auth():
+@app.get("/oauth2/github")
+async def oauth2_github():
     """GitHub 授权入口"""
     state = secrets.token_urlsafe(32)
     auth_url = await github_client.get_authorization_url(
@@ -253,9 +164,9 @@ async def github_auth():
     return RedirectResponse(url=auth_url)
 
 
-@app.get("/auth/github/callback")
-async def github_callback(
-        oauth_result: tuple = Depends(github_oauth)
+@app.get("/oauth2/github/callback")
+async def oauth2_github_callback(
+    oauth_result: Annotated[FastAPIOAuth20, Depends(github_oauth)]
 ):
     """GitHub 授权回调"""
     token_data, state = oauth_result
diff --git a/mkdocs.yml b/mkdocs.yml
index 3fb5580..a78e217 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -10,8 +10,6 @@ nav:
   - 安装: install.md
   - 名词解释: explanation.md
   - 用法: usage.md
-  - 集成:
-      - FastAPI: fastapi.md
   - 客户端状态: status.md
   - 客户端申请:
       - LinuxDo: clients/linuxdo.md
diff --git a/tests/clients/test_feishu.py b/tests/clients/test_feishu.py
index a68b8e7..399d890 100644
--- a/tests/clients/test_feishu.py
+++ b/tests/clients/test_feishu.py
@@ -4,7 +4,7 @@
 import pytest
 import respx
 
-from fastapi_oauth20.clients.feishu import FeiShuOAuth20
+from fastapi_oauth20 import FeiShuOAuth20
 from fastapi_oauth20.errors import GetUserInfoError, HTTPXOAuth20Error
 from fastapi_oauth20.oauth20 import OAuth20Base
 from tests.conftest import (
@@ -16,9 +16,13 @@
     mock_user_info_response,
 )
 
-# Constants specific to this test file
-CUSTOM_CLIENT_ID = 'custom_id'
-CUSTOM_CLIENT_SECRET = 'custom_secret'
+FEISHU_USER_INFO_URL = 'https://passport.feishu.cn/suite/passport/oauth/userinfo'
+
+
+@pytest.fixture
+def feishu_client():
+    """Create FeiShu OAuth2 client instance for testing."""
+    return FeiShuOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
 
 
 class TestFeiShuOAuth20:
@@ -39,9 +43,9 @@ def test_feishu_client_initialization(self, feishu_client):
 
     def test_feishu_client_initialization_with_custom_credentials(self):
         """Test FeiShu client initialization with custom credentials."""
-        client = FeiShuOAuth20(client_id=CUSTOM_CLIENT_ID, client_secret=CUSTOM_CLIENT_SECRET)
-        assert client.client_id == CUSTOM_CLIENT_ID
-        assert client.client_secret == CUSTOM_CLIENT_SECRET
+        client = FeiShuOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
+        assert client.client_id == TEST_CLIENT_ID
+        assert client.client_secret == TEST_CLIENT_SECRET
 
     def test_feishu_client_inheritance(self, feishu_client):
         """Test that FeiShu client properly inherits from OAuth20Base."""
@@ -81,11 +85,7 @@ def test_feishu_client_multiple_instances(self):
     async def test_get_userinfo_success(self, feishu_client):
         """Test successful user info retrieval from FeiShu API."""
         mock_user_data = create_mock_user_data('feishu')
-        mock_user_info_response(
-            respx,
-            {'name': 'feishu', 'user_info_url': 'https://passport.feishu.cn/suite/passport/oauth/userinfo'},
-            mock_user_data,
-        )
+        mock_user_info_response(respx, FEISHU_USER_INFO_URL, mock_user_data)
 
         result = await feishu_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == mock_user_data
@@ -95,11 +95,7 @@ async def test_get_userinfo_success(self, feishu_client):
     async def test_get_userinfo_with_different_access_token(self, feishu_client):
         """Test user info retrieval with different access tokens."""
         mock_user_data = create_mock_user_data('feishu', user_id='user_789', name='Another User')
-        mock_user_info_response(
-            respx,
-            {'name': 'feishu', 'user_info_url': 'https://passport.feishu.cn/suite/passport/oauth/userinfo'},
-            mock_user_data,
-        )
+        mock_user_info_response(respx, FEISHU_USER_INFO_URL, mock_user_data)
 
         result = await feishu_client.get_userinfo('different_token')
         assert result == mock_user_data
@@ -108,9 +104,7 @@ async def test_get_userinfo_with_different_access_token(self, feishu_client):
     @respx.mock
     async def test_get_userinfo_empty_response(self, feishu_client):
         """Test handling of empty user info response."""
-        mock_user_info_response(
-            respx, {'name': 'feishu', 'user_info_url': 'https://passport.feishu.cn/suite/passport/oauth/userinfo'}, {}
-        )
+        mock_user_info_response(respx, FEISHU_USER_INFO_URL, {})
 
         result = await feishu_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == {}
@@ -120,11 +114,7 @@ async def test_get_userinfo_empty_response(self, feishu_client):
     async def test_get_userinfo_partial_data(self, feishu_client):
         """Test handling of partial user info response."""
         partial_data = {'user_id': 'test_user', 'name': 'Test User'}
-        mock_user_info_response(
-            respx,
-            {'name': 'feishu', 'user_info_url': 'https://passport.feishu.cn/suite/passport/oauth/userinfo'},
-            partial_data,
-        )
+        mock_user_info_response(respx, FEISHU_USER_INFO_URL, partial_data)
 
         result = await feishu_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == partial_data
@@ -134,11 +124,7 @@ async def test_get_userinfo_partial_data(self, feishu_client):
     async def test_get_userinfo_authorization_header(self, feishu_client):
         """Test that authorization header is correctly formatted."""
         mock_user_data = {'user_id': 'test_user'}
-        route = mock_user_info_response(
-            respx,
-            {'name': 'feishu', 'user_info_url': 'https://passport.feishu.cn/suite/passport/oauth/userinfo'},
-            mock_user_data,
-        )
+        route = mock_user_info_response(respx, FEISHU_USER_INFO_URL, mock_user_data)
 
         await feishu_client.get_userinfo(TEST_ACCESS_TOKEN)
 
@@ -151,9 +137,7 @@ async def test_get_userinfo_authorization_header(self, feishu_client):
     @respx.mock
     async def test_get_userinfo_http_error_401(self, feishu_client):
         """Test handling of 401 HTTP error when getting user info."""
-        respx.get('https://passport.feishu.cn/suite/passport/oauth/userinfo').mock(
-            return_value=httpx.Response(401, text='Unauthorized')
-        )
+        respx.get(FEISHU_USER_INFO_URL).mock(return_value=httpx.Response(401, text='Unauthorized'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await feishu_client.get_userinfo(INVALID_TOKEN)
@@ -162,9 +146,7 @@ async def test_get_userinfo_http_error_401(self, feishu_client):
     @respx.mock
     async def test_get_userinfo_http_error_403(self, feishu_client):
         """Test handling of 403 HTTP error when getting user info."""
-        respx.get('https://passport.feishu.cn/suite/passport/oauth/userinfo').mock(
-            return_value=httpx.Response(403, text='Forbidden')
-        )
+        respx.get(FEISHU_USER_INFO_URL).mock(return_value=httpx.Response(403, text='Forbidden'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await feishu_client.get_userinfo(TEST_ACCESS_TOKEN)
@@ -173,9 +155,7 @@ async def test_get_userinfo_http_error_403(self, feishu_client):
     @respx.mock
     async def test_get_userinfo_http_error_500(self, feishu_client):
         """Test handling of 500 HTTP error when getting user info."""
-        respx.get('https://passport.feishu.cn/suite/passport/oauth/userinfo').mock(
-            return_value=httpx.Response(500, text='Internal Server Error')
-        )
+        respx.get(FEISHU_USER_INFO_URL).mock(return_value=httpx.Response(500, text='Internal Server Error'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await feishu_client.get_userinfo(TEST_ACCESS_TOKEN)
@@ -184,9 +164,7 @@ async def test_get_userinfo_http_error_500(self, feishu_client):
     @respx.mock
     async def test_get_userinfo_invalid_json(self, feishu_client):
         """Test handling of invalid JSON response."""
-        respx.get('https://passport.feishu.cn/suite/passport/oauth/userinfo').mock(
-            return_value=httpx.Response(200, text='invalid json')
-        )
+        respx.get(FEISHU_USER_INFO_URL).mock(return_value=httpx.Response(200, text='invalid json'))
 
         with pytest.raises(GetUserInfoError):
             await feishu_client.get_userinfo(TEST_ACCESS_TOKEN)
diff --git a/tests/clients/test_gitee.py b/tests/clients/test_gitee.py
index 7afa4a9..cc6e516 100644
--- a/tests/clients/test_gitee.py
+++ b/tests/clients/test_gitee.py
@@ -4,7 +4,7 @@
 import pytest
 import respx
 
-from fastapi_oauth20.clients.gitee import GiteeOAuth20
+from fastapi_oauth20 import GiteeOAuth20
 from fastapi_oauth20.errors import GetUserInfoError, HTTPXOAuth20Error
 from fastapi_oauth20.oauth20 import OAuth20Base
 from tests.conftest import (
@@ -16,9 +16,13 @@
     mock_user_info_response,
 )
 
-# Constants specific to this test file
-CUSTOM_CLIENT_ID = 'custom_id'
-CUSTOM_CLIENT_SECRET = 'custom_secret'
+GITEE_USER_INFO_URL = 'https://gitee.com/api/v5/user'
+
+
+@pytest.fixture
+def gitee_client():
+    """Create Gitee OAuth2 client instance for testing."""
+    return GiteeOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
 
 
 class TestGiteeOAuth20:
@@ -35,9 +39,9 @@ def test_gitee_client_initialization(self, gitee_client):
 
     def test_gitee_client_initialization_with_custom_credentials(self):
         """Test Gitee client initialization with custom credentials."""
-        client = GiteeOAuth20(client_id=CUSTOM_CLIENT_ID, client_secret=CUSTOM_CLIENT_SECRET)
-        assert client.client_id == CUSTOM_CLIENT_ID
-        assert client.client_secret == CUSTOM_CLIENT_SECRET
+        client = GiteeOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
+        assert client.client_id == TEST_CLIENT_ID
+        assert client.client_secret == TEST_CLIENT_SECRET
 
     def test_gitee_client_inheritance(self, gitee_client):
         """Test that Gitee client properly inherits from OAuth20Base."""
@@ -67,9 +71,7 @@ def test_gitee_client_endpoint_urls(self):
     async def test_get_userinfo_success(self, gitee_client):
         """Test successful user info retrieval from Gitee API."""
         mock_user_data = create_mock_user_data('gitee')
-        mock_user_info_response(
-            respx, {'name': 'gitee', 'user_info_url': 'https://gitee.com/api/v5/user'}, mock_user_data
-        )
+        mock_user_info_response(respx, GITEE_USER_INFO_URL, mock_user_data)
 
         result = await gitee_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == mock_user_data
@@ -79,9 +81,7 @@ async def test_get_userinfo_success(self, gitee_client):
     async def test_get_userinfo_authorization_header(self, gitee_client):
         """Test that authorization header is correctly formatted."""
         mock_user_data = {'id': 'test_user'}
-        route = mock_user_info_response(
-            respx, {'name': 'gitee', 'user_info_url': 'https://gitee.com/api/v5/user'}, mock_user_data
-        )
+        route = mock_user_info_response(respx, GITEE_USER_INFO_URL, mock_user_data)
 
         await gitee_client.get_userinfo(TEST_ACCESS_TOKEN)
 
@@ -94,7 +94,7 @@ async def test_get_userinfo_authorization_header(self, gitee_client):
     @respx.mock
     async def test_get_userinfo_http_error(self, gitee_client):
         """Test handling of HTTP errors when getting user info."""
-        respx.get('https://gitee.com/api/v5/user').mock(return_value=httpx.Response(401, text='Unauthorized'))
+        respx.get(GITEE_USER_INFO_URL).mock(return_value=httpx.Response(401, text='Unauthorized'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await gitee_client.get_userinfo(INVALID_TOKEN)
@@ -103,7 +103,7 @@ async def test_get_userinfo_http_error(self, gitee_client):
     @respx.mock
     async def test_get_userinfo_empty_response(self, gitee_client):
         """Test handling of empty user info response."""
-        mock_user_info_response(respx, {'name': 'gitee', 'user_info_url': 'https://gitee.com/api/v5/user'}, {})
+        mock_user_info_response(respx, GITEE_USER_INFO_URL, {})
 
         result = await gitee_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == {}
@@ -113,9 +113,7 @@ async def test_get_userinfo_empty_response(self, gitee_client):
     async def test_get_userinfo_partial_data(self, gitee_client):
         """Test handling of partial user info response."""
         partial_data = {'id': 123456, 'login': 'testuser'}
-        mock_user_info_response(
-            respx, {'name': 'gitee', 'user_info_url': 'https://gitee.com/api/v5/user'}, partial_data
-        )
+        mock_user_info_response(respx, GITEE_USER_INFO_URL, partial_data)
 
         result = await gitee_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == partial_data
@@ -124,7 +122,7 @@ async def test_get_userinfo_partial_data(self, gitee_client):
     @respx.mock
     async def test_get_userinfo_invalid_json(self, gitee_client):
         """Test handling of invalid JSON response."""
-        respx.get('https://gitee.com/api/v5/user').mock(return_value=httpx.Response(200, text='invalid json'))
+        respx.get(GITEE_USER_INFO_URL).mock(return_value=httpx.Response(200, text='invalid json'))
 
         with pytest.raises(GetUserInfoError):
             await gitee_client.get_userinfo(TEST_ACCESS_TOKEN)
diff --git a/tests/clients/test_github.py b/tests/clients/test_github.py
index acd13d2..064ec57 100644
--- a/tests/clients/test_github.py
+++ b/tests/clients/test_github.py
@@ -4,7 +4,7 @@
 import pytest
 import respx
 
-from fastapi_oauth20.clients.github import GitHubOAuth20
+from fastapi_oauth20 import GitHubOAuth20
 from fastapi_oauth20.errors import GetUserInfoError, HTTPXOAuth20Error
 from fastapi_oauth20.oauth20 import OAuth20Base
 from tests.conftest import (
@@ -16,9 +16,15 @@
     mock_user_info_response,
 )
 
-# Constants specific to this test file
-CUSTOM_CLIENT_ID = 'custom_id'
-CUSTOM_CLIENT_SECRET = 'custom_secret'
+GITHUB_TOKEN_URL = 'https://github.com/login/oauth/access_token'
+GITHUB_USER_INFO_URL = 'https://api.github.com/user'
+GITHUB_EMAILS_URL = 'https://api.github.com/user/emails'
+
+
+@pytest.fixture
+def github_client():
+    """Create GitHub OAuth2 client instance for testing."""
+    return GitHubOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
 
 
 class TestGitHubOAuth20:
@@ -34,9 +40,9 @@ def test_github_client_initialization(self, github_client):
 
     def test_github_client_initialization_with_custom_credentials(self):
         """Test GitHub client initialization with custom credentials."""
-        client = GitHubOAuth20(client_id=CUSTOM_CLIENT_ID, client_secret=CUSTOM_CLIENT_SECRET)
-        assert client.client_id == CUSTOM_CLIENT_ID
-        assert client.client_secret == CUSTOM_CLIENT_SECRET
+        client = GitHubOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
+        assert client.client_id == TEST_CLIENT_ID
+        assert client.client_secret == TEST_CLIENT_SECRET
 
     def test_github_client_inheritance(self, github_client):
         """Test that GitHub client properly inherits from OAuth20Base."""
@@ -75,9 +81,7 @@ def test_github_client_multiple_instances(self):
     async def test_get_userinfo_success_with_email(self, github_client):
         """Test successful user info retrieval from GitHub API with email included."""
         mock_user_data = create_mock_user_data('github')
-        mock_user_info_response(
-            respx, {'name': 'github', 'user_info_url': 'https://api.github.com/user'}, mock_user_data
-        )
+        mock_user_info_response(respx, GITHUB_USER_INFO_URL, mock_user_data)
 
         result = await github_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == mock_user_data
@@ -87,12 +91,10 @@ async def test_get_userinfo_success_with_email(self, github_client):
     async def test_get_userinfo_success_without_email(self, github_client):
         """Test successful user info retrieval from GitHub API without email."""
         mock_user_data = create_mock_user_data('github', email=None)
-        mock_user_info_response(
-            respx, {'name': 'github', 'user_info_url': 'https://api.github.com/user'}, mock_user_data
-        )
+        mock_user_info_response(respx, GITHUB_USER_INFO_URL, mock_user_data)
         # Mock emails endpoint
         emails_data = [{'email': 'test@example.com', 'primary': True}]
-        respx.get('https://api.github.com/user/emails').mock(return_value=httpx.Response(200, json=emails_data))
+        respx.get(GITHUB_EMAILS_URL).mock(return_value=httpx.Response(200, json=emails_data))
 
         result = await github_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result['login'] == mock_user_data['login']
@@ -103,9 +105,7 @@ async def test_get_userinfo_success_without_email(self, github_client):
     async def test_get_userinfo_with_different_access_token(self, github_client):
         """Test user info retrieval with different access tokens."""
         mock_user_data = create_mock_user_data('github', id=789, login='different_user')
-        mock_user_info_response(
-            respx, {'name': 'github', 'user_info_url': 'https://api.github.com/user'}, mock_user_data
-        )
+        mock_user_info_response(respx, GITHUB_USER_INFO_URL, mock_user_data)
 
         result = await github_client.get_userinfo('different_token')
         assert result == mock_user_data
@@ -115,9 +115,7 @@ async def test_get_userinfo_with_different_access_token(self, github_client):
     async def test_get_userinfo_authorization_header(self, github_client):
         """Test that authorization header is correctly formatted."""
         mock_user_data = {'id': 'test_user', 'email': 'test@example.com'}  # Include email to avoid emails endpoint call
-        route = mock_user_info_response(
-            respx, {'name': 'github', 'user_info_url': 'https://api.github.com/user'}, mock_user_data
-        )
+        route = mock_user_info_response(respx, GITHUB_USER_INFO_URL, mock_user_data)
 
         await github_client.get_userinfo(TEST_ACCESS_TOKEN)
 
@@ -130,7 +128,7 @@ async def test_get_userinfo_authorization_header(self, github_client):
     @respx.mock
     async def test_get_userinfo_http_error_401(self, github_client):
         """Test handling of 401 HTTP error when getting user info."""
-        respx.get('https://api.github.com/user').mock(return_value=httpx.Response(401, text='Unauthorized'))
+        respx.get(GITHUB_USER_INFO_URL).mock(return_value=httpx.Response(401, text='Unauthorized'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await github_client.get_userinfo(INVALID_TOKEN)
@@ -139,7 +137,7 @@ async def test_get_userinfo_http_error_401(self, github_client):
     @respx.mock
     async def test_get_userinfo_http_error_403(self, github_client):
         """Test handling of 403 HTTP error when getting user info."""
-        respx.get('https://api.github.com/user').mock(return_value=httpx.Response(403, text='Forbidden'))
+        respx.get(GITHUB_USER_INFO_URL).mock(return_value=httpx.Response(403, text='Forbidden'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await github_client.get_userinfo(TEST_ACCESS_TOKEN)
@@ -148,7 +146,7 @@ async def test_get_userinfo_http_error_403(self, github_client):
     @respx.mock
     async def test_get_userinfo_http_error_500(self, github_client):
         """Test handling of 500 HTTP error when getting user info."""
-        respx.get('https://api.github.com/user').mock(return_value=httpx.Response(500, text='Internal Server Error'))
+        respx.get(GITHUB_USER_INFO_URL).mock(return_value=httpx.Response(500, text='Internal Server Error'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await github_client.get_userinfo(TEST_ACCESS_TOKEN)
@@ -157,7 +155,7 @@ async def test_get_userinfo_http_error_500(self, github_client):
     @respx.mock
     async def test_get_userinfo_invalid_json(self, github_client):
         """Test handling of invalid JSON response."""
-        respx.get('https://api.github.com/user').mock(return_value=httpx.Response(200, text='invalid json'))
+        respx.get(GITHUB_USER_INFO_URL).mock(return_value=httpx.Response(200, text='invalid json'))
 
         with pytest.raises(GetUserInfoError):
             await github_client.get_userinfo(TEST_ACCESS_TOKEN)
@@ -166,10 +164,10 @@ async def test_get_userinfo_invalid_json(self, github_client):
     @respx.mock
     async def test_get_userinfo_empty_response(self, github_client):
         """Test handling of empty user info response."""
-        mock_user_info_response(respx, {'name': 'github', 'user_info_url': 'https://api.github.com/user'}, {})
+        mock_user_info_response(respx, GITHUB_USER_INFO_URL, {})
         # Mock emails endpoint since empty response will trigger email lookup
         emails_data = [{'email': 'test@example.com', 'primary': True}]
-        respx.get('https://api.github.com/user/emails').mock(return_value=httpx.Response(200, json=emails_data))
+        respx.get(GITHUB_EMAILS_URL).mock(return_value=httpx.Response(200, json=emails_data))
 
         result = await github_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result['email'] == 'test@example.com'
@@ -183,7 +181,7 @@ async def test_get_userinfo_partial_data(self, github_client):
             'login': 'testuser',
             'email': 'test@example.com',
         }  # Add email to avoid emails endpoint call
-        mock_user_info_response(respx, {'name': 'github', 'user_info_url': 'https://api.github.com/user'}, partial_data)
+        mock_user_info_response(respx, GITHUB_USER_INFO_URL, partial_data)
 
         result = await github_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == partial_data
@@ -198,7 +196,7 @@ async def test_get_userinfo_rate_limit(self, github_client):
             'documentation_url': 'https://docs.github.com/rest/overview/rate-limits-for-the-rest-api',
         }
 
-        respx.get('https://api.github.com/user').mock(return_value=httpx.Response(403, json=rate_limit_response))
+        respx.get(GITHUB_USER_INFO_URL).mock(return_value=httpx.Response(403, json=rate_limit_response))
 
         with pytest.raises(HTTPXOAuth20Error):
             await github_client.get_userinfo(TEST_ACCESS_TOKEN)
diff --git a/tests/clients/test_google.py b/tests/clients/test_google.py
index 505db53..e2ce547 100644
--- a/tests/clients/test_google.py
+++ b/tests/clients/test_google.py
@@ -4,7 +4,7 @@
 import pytest
 import respx
 
-from fastapi_oauth20.clients.google import GoogleOAuth20
+from fastapi_oauth20 import GoogleOAuth20
 from fastapi_oauth20.errors import GetUserInfoError, HTTPXOAuth20Error
 from fastapi_oauth20.oauth20 import OAuth20Base
 from tests.conftest import (
@@ -16,9 +16,13 @@
     mock_user_info_response,
 )
 
-# Constants specific to this test file
-CUSTOM_CLIENT_ID = 'custom_id'
-CUSTOM_CLIENT_SECRET = 'custom_secret'
+GOOGLE_USER_INFO_URL = 'https://www.googleapis.com/oauth2/v1/userinfo'
+
+
+@pytest.fixture
+def google_client():
+    """Create Google OAuth2 client instance for testing."""
+    return GoogleOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
 
 
 class TestGoogleOAuth20:
@@ -36,9 +40,9 @@ def test_google_client_initialization(self, google_client):
 
     def test_google_client_initialization_with_custom_credentials(self):
         """Test Google client initialization with custom credentials."""
-        client = GoogleOAuth20(client_id=CUSTOM_CLIENT_ID, client_secret=CUSTOM_CLIENT_SECRET)
-        assert client.client_id == CUSTOM_CLIENT_ID
-        assert client.client_secret == CUSTOM_CLIENT_SECRET
+        client = GoogleOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
+        assert client.client_id == TEST_CLIENT_ID
+        assert client.client_secret == TEST_CLIENT_SECRET
 
     def test_google_client_inheritance(self, google_client):
         """Test that Google client properly inherits from OAuth20Base."""
@@ -71,9 +75,7 @@ def test_google_client_endpoint_urls(self):
     async def test_get_userinfo_success(self, google_client):
         """Test successful user info retrieval from Google OAuth2 API."""
         mock_user_data = create_mock_user_data('google')
-        mock_user_info_response(
-            respx, {'name': 'google', 'user_info_url': 'https://www.googleapis.com/oauth2/v1/userinfo'}, mock_user_data
-        )
+        mock_user_info_response(respx, GOOGLE_USER_INFO_URL, mock_user_data)
 
         result = await google_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == mock_user_data
@@ -83,9 +85,7 @@ async def test_get_userinfo_success(self, google_client):
     async def test_get_userinfo_authorization_header(self, google_client):
         """Test that authorization header is correctly formatted."""
         mock_user_data = {'id': 'test_user'}
-        route = mock_user_info_response(
-            respx, {'name': 'google', 'user_info_url': 'https://www.googleapis.com/oauth2/v1/userinfo'}, mock_user_data
-        )
+        route = mock_user_info_response(respx, GOOGLE_USER_INFO_URL, mock_user_data)
 
         await google_client.get_userinfo(TEST_ACCESS_TOKEN)
 
@@ -98,9 +98,7 @@ async def test_get_userinfo_authorization_header(self, google_client):
     @respx.mock
     async def test_get_userinfo_http_error(self, google_client):
         """Test handling of HTTP errors when getting user info."""
-        respx.get('https://www.googleapis.com/oauth2/v1/userinfo').mock(
-            return_value=httpx.Response(401, text='Unauthorized')
-        )
+        respx.get(GOOGLE_USER_INFO_URL).mock(return_value=httpx.Response(401, text='Unauthorized'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await google_client.get_userinfo(INVALID_TOKEN)
@@ -109,9 +107,7 @@ async def test_get_userinfo_http_error(self, google_client):
     @respx.mock
     async def test_get_userinfo_empty_response(self, google_client):
         """Test handling of empty user info response."""
-        mock_user_info_response(
-            respx, {'name': 'google', 'user_info_url': 'https://www.googleapis.com/oauth2/v1/userinfo'}, {}
-        )
+        mock_user_info_response(respx, GOOGLE_USER_INFO_URL, {})
 
         result = await google_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == {}
@@ -121,9 +117,7 @@ async def test_get_userinfo_empty_response(self, google_client):
     async def test_get_userinfo_partial_data(self, google_client):
         """Test handling of partial user info response."""
         partial_data = {'id': '123456789', 'email': 'test@example.com'}
-        mock_user_info_response(
-            respx, {'name': 'google', 'user_info_url': 'https://www.googleapis.com/oauth2/v1/userinfo'}, partial_data
-        )
+        mock_user_info_response(respx, GOOGLE_USER_INFO_URL, partial_data)
 
         result = await google_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == partial_data
@@ -132,9 +126,7 @@ async def test_get_userinfo_partial_data(self, google_client):
     @respx.mock
     async def test_get_userinfo_invalid_json(self, google_client):
         """Test handling of invalid JSON response."""
-        respx.get('https://www.googleapis.com/oauth2/v1/userinfo').mock(
-            return_value=httpx.Response(200, text='invalid json')
-        )
+        respx.get(GOOGLE_USER_INFO_URL).mock(return_value=httpx.Response(200, text='invalid json'))
 
         with pytest.raises(GetUserInfoError):
             await google_client.get_userinfo(TEST_ACCESS_TOKEN)
diff --git a/tests/clients/test_linuxdo.py b/tests/clients/test_linuxdo.py
index 1201c35..f5cd3b9 100644
--- a/tests/clients/test_linuxdo.py
+++ b/tests/clients/test_linuxdo.py
@@ -4,7 +4,7 @@
 import pytest
 import respx
 
-from fastapi_oauth20.clients.linuxdo import LinuxDoOAuth20
+from fastapi_oauth20 import LinuxDoOAuth20
 from fastapi_oauth20.errors import HTTPXOAuth20Error
 from fastapi_oauth20.oauth20 import OAuth20Base
 from tests.conftest import (
@@ -16,9 +16,13 @@
     mock_user_info_response,
 )
 
-# Constants specific to this test file
-CUSTOM_CLIENT_ID = 'custom_id'
-CUSTOM_CLIENT_SECRET = 'custom_secret'
+LINUXDO_USER_INFO_URL = 'https://connect.linux.do/api/user'
+
+
+@pytest.fixture
+def linuxdo_client():
+    """Create LinuxDo OAuth2 client instance for testing."""
+    return LinuxDoOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
 
 
 class TestLinuxDoOAuth20:
@@ -36,9 +40,9 @@ def test_linuxdo_client_initialization(self, linuxdo_client):
 
     def test_linuxdo_client_initialization_with_custom_credentials(self):
         """Test LinuxDo client initialization with custom credentials."""
-        client = LinuxDoOAuth20(client_id=CUSTOM_CLIENT_ID, client_secret=CUSTOM_CLIENT_SECRET)
-        assert client.client_id == CUSTOM_CLIENT_ID
-        assert client.client_secret == CUSTOM_CLIENT_SECRET
+        client = LinuxDoOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
+        assert client.client_id == TEST_CLIENT_ID
+        assert client.client_secret == TEST_CLIENT_SECRET
 
     def test_linuxdo_client_inheritance(self, linuxdo_client):
         """Test that LinuxDo client properly inherits from OAuth20Base."""
@@ -66,9 +70,7 @@ def test_linuxdo_client_endpoint_urls(self):
     async def test_get_userinfo_success(self, linuxdo_client):
         """Test successful user info retrieval from LinuxDo API."""
         mock_user_data = create_mock_user_data('linuxdo')
-        mock_user_info_response(
-            respx, {'name': 'linuxdo', 'user_info_url': 'https://connect.linux.do/api/user'}, mock_user_data
-        )
+        mock_user_info_response(respx, LINUXDO_USER_INFO_URL, mock_user_data)
 
         result = await linuxdo_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == mock_user_data
@@ -78,9 +80,7 @@ async def test_get_userinfo_success(self, linuxdo_client):
     async def test_get_userinfo_authorization_header(self, linuxdo_client):
         """Test that authorization header is correctly formatted."""
         mock_user_data = {'id': 'test_user'}
-        route = mock_user_info_response(
-            respx, {'name': 'linuxdo', 'user_info_url': 'https://connect.linux.do/api/user'}, mock_user_data
-        )
+        route = mock_user_info_response(respx, LINUXDO_USER_INFO_URL, mock_user_data)
 
         await linuxdo_client.get_userinfo(TEST_ACCESS_TOKEN)
 
@@ -93,7 +93,7 @@ async def test_get_userinfo_authorization_header(self, linuxdo_client):
     @respx.mock
     async def test_get_userinfo_http_error(self, linuxdo_client):
         """Test handling of HTTP errors when getting user info."""
-        respx.get('https://connect.linux.do/api/user').mock(return_value=httpx.Response(401, text='Unauthorized'))
+        respx.get(LINUXDO_USER_INFO_URL).mock(return_value=httpx.Response(401, text='Unauthorized'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await linuxdo_client.get_userinfo(INVALID_TOKEN)
diff --git a/tests/clients/test_oschina.py b/tests/clients/test_oschina.py
index 95cc411..b4b22d8 100644
--- a/tests/clients/test_oschina.py
+++ b/tests/clients/test_oschina.py
@@ -4,7 +4,7 @@
 import pytest
 import respx
 
-from fastapi_oauth20.clients.oschina import OSChinaOAuth20
+from fastapi_oauth20 import OSChinaOAuth20
 from fastapi_oauth20.errors import HTTPXOAuth20Error
 from fastapi_oauth20.oauth20 import OAuth20Base
 from tests.conftest import (
@@ -16,9 +16,13 @@
     mock_user_info_response,
 )
 
-# Constants specific to this test file
-CUSTOM_CLIENT_ID = 'custom_id'
-CUSTOM_CLIENT_SECRET = 'custom_secret'
+OSCHINA_USER_INFO_URL = 'https://www.oschina.net/action/openapi/user'
+
+
+@pytest.fixture
+def oschina_client():
+    """Create OSChina OAuth2 client instance for testing."""
+    return OSChinaOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
 
 
 class TestOSChinaOAuth20:
@@ -35,9 +39,9 @@ def test_oschina_client_initialization(self, oschina_client):
 
     def test_oschina_client_initialization_with_custom_credentials(self):
         """Test OSChina client initialization with custom credentials."""
-        client = OSChinaOAuth20(client_id=CUSTOM_CLIENT_ID, client_secret=CUSTOM_CLIENT_SECRET)
-        assert client.client_id == CUSTOM_CLIENT_ID
-        assert client.client_secret == CUSTOM_CLIENT_SECRET
+        client = OSChinaOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
+        assert client.client_id == TEST_CLIENT_ID
+        assert client.client_secret == TEST_CLIENT_SECRET
 
     def test_oschina_client_inheritance(self, oschina_client):
         """Test that OSChina client properly inherits from OAuth20Base."""
@@ -65,11 +69,7 @@ def test_oschina_client_endpoint_urls(self):
     async def test_get_userinfo_success(self, oschina_client):
         """Test successful user info retrieval from OSChina API."""
         mock_user_data = create_mock_user_data('oschina')
-        mock_user_info_response(
-            respx,
-            {'name': 'oschina', 'user_info_url': 'https://www.oschina.net/action/openapi/user'},
-            mock_user_data,
-        )
+        mock_user_info_response(respx, OSCHINA_USER_INFO_URL, mock_user_data)
 
         result = await oschina_client.get_userinfo(TEST_ACCESS_TOKEN)
         assert result == mock_user_data
@@ -79,11 +79,7 @@ async def test_get_userinfo_success(self, oschina_client):
     async def test_get_userinfo_authorization_header(self, oschina_client):
         """Test that authorization header is correctly formatted."""
         mock_user_data = {'id': 'test_user'}
-        route = mock_user_info_response(
-            respx,
-            {'name': 'oschina', 'user_info_url': 'https://www.oschina.net/action/openapi/user'},
-            mock_user_data,
-        )
+        route = mock_user_info_response(respx, OSCHINA_USER_INFO_URL, mock_user_data)
 
         await oschina_client.get_userinfo(TEST_ACCESS_TOKEN)
 
@@ -96,9 +92,7 @@ async def test_get_userinfo_authorization_header(self, oschina_client):
     @respx.mock
     async def test_get_userinfo_http_error(self, oschina_client):
         """Test handling of HTTP errors when getting user info."""
-        respx.get('https://www.oschina.net/action/openapi/user').mock(
-            return_value=httpx.Response(401, text='Unauthorized')
-        )
+        respx.get(OSCHINA_USER_INFO_URL).mock(return_value=httpx.Response(401, text='Unauthorized'))
 
         with pytest.raises(HTTPXOAuth20Error):
             await oschina_client.get_userinfo(INVALID_TOKEN)
diff --git a/tests/conftest.py b/tests/conftest.py
index 80e6a66..9c1a48f 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,147 +1,12 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
-
-"""
-Global constants and shared fixtures for fastapi-oauth20 tests.
-"""
-
 import httpx
-import pytest
-
-from fastapi import Depends, FastAPI
-from fastapi.testclient import TestClient
-
-from fastapi_oauth20.clients.feishu import FeiShuOAuth20
-from fastapi_oauth20.clients.gitee import GiteeOAuth20
-from fastapi_oauth20.clients.github import GitHubOAuth20
-from fastapi_oauth20.clients.google import GoogleOAuth20
-from fastapi_oauth20.clients.linuxdo import LinuxDoOAuth20
-from fastapi_oauth20.clients.oschina import OSChinaOAuth20
 
 TEST_CLIENT_ID = 'test_client_id'
 TEST_CLIENT_SECRET = 'test_client_secret'
 TEST_ACCESS_TOKEN = 'test_access_token'
 INVALID_TOKEN = 'invalid_token'
 TEST_STATE = 'test_state'
-OAUTH_PROVIDERS = [
-    {
-        'name': 'github',
-        'client_class': GitHubOAuth20,
-        'token_url': 'https://github.com/login/oauth/access_token',
-        'user_info_url': 'https://api.github.com/user',
-        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'scope': 'user'},
-        'redirect_uri': 'http://localhost:8000/auth/github/callback',
-    },
-    {
-        'name': 'google',
-        'client_class': GoogleOAuth20,
-        'token_url': 'https://oauth2.googleapis.com/token',
-        'user_info_url': 'https://www.googleapis.com/oauth2/v1/userinfo',
-        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'Bearer', 'expires_in': 3600},
-        'redirect_uri': 'http://localhost:8000/auth/google/callback',
-    },
-    {
-        'name': 'gitee',
-        'client_class': GiteeOAuth20,
-        'token_url': 'https://gitee.com/oauth/token',
-        'user_info_url': 'https://gitee.com/api/v5/user',
-        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'scope': 'user_info'},
-        'redirect_uri': 'http://localhost:8000/auth/gitee/callback',
-    },
-    {
-        'name': 'feishu',
-        'client_class': FeiShuOAuth20,
-        'token_url': 'https://passport.feishu.cn/suite/passport/oauth/token',
-        'user_info_url': 'https://passport.feishu.cn/suite/passport/oauth/userinfo',
-        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'expires_in': 3600},
-        'redirect_uri': 'http://localhost:8000/auth/feishu/callback',
-    },
-    {
-        'name': 'linuxdo',
-        'client_class': LinuxDoOAuth20,
-        'token_url': 'https://connect.linux.do/oauth2/token',
-        'user_info_url': 'https://connect.linux.do/api/user',
-        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'expires_in': 3600},
-        'redirect_uri': 'http://localhost:8000/auth/linuxdo/callback',
-    },
-    {
-        'name': 'oschina',
-        'client_class': OSChinaOAuth20,
-        'token_url': 'https://www.oschina.net/action/openapi/token',
-        'user_info_url': 'https://www.oschina.net/action/openapi/user',
-        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'expires_in': 3600},
-        'redirect_uri': 'http://localhost:8000/auth/oschina/callback',
-    },
-]
-
-
-@pytest.fixture(params=OAUTH_PROVIDERS)
-def oauth_provider_config(request):
-    """Get OAuth provider configuration."""
-    return request.param
-
-
-@pytest.fixture
-def oauth_client(oauth_provider_config):
-    """Create OAuth2 client for testing based on provider config."""
-    provider_config = oauth_provider_config
-    client_class = provider_config['client_class']
-    return client_class(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
-
-
-@pytest.fixture
-def fastapi_app():
-    """Create FastAPI app for testing."""
-    app = FastAPI()
-
-    @app.get('/')
-    async def root():
-        return {'message': 'OAuth2 Test App'}
-
-    return app
-
-
-@pytest.fixture
-def test_client(fastapi_app):
-    """Create TestClient for FastAPI app."""
-    return TestClient(fastapi_app)
-
-
-# Individual OAuth client fixtures for non-parametrized tests
-@pytest.fixture
-def github_client():
-    """Create GitHub OAuth2 client instance for testing."""
-    return GitHubOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
-
-
-@pytest.fixture
-def google_client():
-    """Create Google OAuth2 client instance for testing."""
-    return GoogleOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
-
-
-@pytest.fixture
-def gitee_client():
-    """Create Gitee OAuth2 client instance for testing."""
-    return GiteeOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
-
-
-@pytest.fixture
-def feishu_client():
-    """Create FeiShu OAuth2 client instance for testing."""
-    return FeiShuOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
-
-
-@pytest.fixture
-def linuxdo_client():
-    """Create LinuxDo OAuth2 client instance for testing."""
-    return LinuxDoOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
-
-
-@pytest.fixture
-def oschina_client():
-    """Create OSChina OAuth2 client instance for testing."""
-    return OSChinaOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
 
 
 def create_mock_user_data(provider_name: str, **overrides):
@@ -195,39 +60,6 @@ def create_mock_user_data(provider_name: str, **overrides):
     return base_data
 
 
-def mock_oauth_token_response(respx_mock, provider_config: dict, status_code: int = 200):
-    """Mock OAuth token endpoint response for a provider."""
-    return respx_mock.post(provider_config['token_url']).mock(
-        return_value=httpx.Response(status_code, json=provider_config['token_response'])
-    )
-
-
-def mock_user_info_response(respx_mock, provider_config: dict, user_data: dict = None, status_code: int = 200):
-    """Mock user info endpoint response for a provider."""
-    if user_data is None:
-        user_data = create_mock_user_data(provider_config['name'])
-    return respx_mock.get(provider_config['user_info_url']).mock(
-        return_value=httpx.Response(status_code, json=user_data)
-    )
-
-
-def setup_oauth_callback_route(app: FastAPI, provider_config: dict, oauth_dependency):
-    """Setup OAuth callback route for testing."""
-    callback_path = f'/auth/{provider_config["name"]}/callback'
-
-    @app.get(callback_path)
-    async def oauth_callback_handler(access_token_state=Depends(oauth_dependency)):
-        token, state = access_token_state
-        return {'provider': provider_config['name'], 'access_token': token, 'state': state}
-
-    return callback_path
-
-
-def assert_oauth_error_response(response, expected_error: str, expected_status: int = 400):
-    """Assert OAuth error response has correct format."""
-    assert response.status_code == expected_status
-    data = response.json()
-    if 'detail' in data:
-        assert data['detail'] == expected_error
-    else:
-        assert data.get('error') == expected_error
+def mock_user_info_response(respx_mock, user_info_url: str, user_data: dict, status_code: int = 200):
+    """Mock user info endpoint response."""
+    return respx_mock.get(user_info_url).mock(return_value=httpx.Response(status_code, json=user_data))
diff --git a/tests/test_fastapi.py b/tests/test_callback.py
similarity index 75%
rename from tests/test_fastapi.py
rename to tests/test_callback.py
index 7010f42..0640b0b 100644
--- a/tests/test_fastapi.py
+++ b/tests/test_callback.py
@@ -8,19 +8,74 @@
 from fastapi.responses import JSONResponse
 from fastapi.testclient import TestClient
 
-from fastapi_oauth20 import FastAPIOAuth20, OAuth20AuthorizeCallbackError
+from fastapi_oauth20 import (
+    FastAPIOAuth20,
+    FeiShuOAuth20,
+    GiteeOAuth20,
+    GitHubOAuth20,
+    GoogleOAuth20,
+    LinuxDoOAuth20,
+    OAuth20AuthorizeCallbackError,
+    OSChinaOAuth20,
+)
 from tests.conftest import (
-    OAUTH_PROVIDERS,
     TEST_ACCESS_TOKEN,
     TEST_CLIENT_ID,
     TEST_CLIENT_SECRET,
     TEST_STATE,
-    assert_oauth_error_response,
-    mock_oauth_token_response,
-    setup_oauth_callback_route,
 )
 
-# Integration test specific constants
+OAUTH_PROVIDERS = [
+    {
+        'name': 'github',
+        'client_class': GitHubOAuth20,
+        'token_url': 'https://github.com/login/oauth/access_token',
+        'user_info_url': 'https://api.github.com/user',
+        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'scope': 'user'},
+        'redirect_uri': 'http://localhost:8000/auth/github/callback',
+    },
+    {
+        'name': 'google',
+        'client_class': GoogleOAuth20,
+        'token_url': 'https://oauth2.googleapis.com/token',
+        'user_info_url': 'https://www.googleapis.com/oauth2/v1/userinfo',
+        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'Bearer', 'expires_in': 3600},
+        'redirect_uri': 'http://localhost:8000/auth/google/callback',
+    },
+    {
+        'name': 'gitee',
+        'client_class': GiteeOAuth20,
+        'token_url': 'https://gitee.com/oauth/token',
+        'user_info_url': 'https://gitee.com/api/v5/user',
+        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'scope': 'user_info'},
+        'redirect_uri': 'http://localhost:8000/auth/gitee/callback',
+    },
+    {
+        'name': 'feishu',
+        'client_class': FeiShuOAuth20,
+        'token_url': 'https://passport.feishu.cn/suite/passport/oauth/token',
+        'user_info_url': 'https://passport.feishu.cn/suite/passport/oauth/userinfo',
+        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'expires_in': 3600},
+        'redirect_uri': 'http://localhost:8000/auth/feishu/callback',
+    },
+    {
+        'name': 'linuxdo',
+        'client_class': LinuxDoOAuth20,
+        'token_url': 'https://connect.linux.do/oauth2/token',
+        'user_info_url': 'https://connect.linux.do/api/user',
+        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'expires_in': 3600},
+        'redirect_uri': 'http://localhost:8000/auth/linuxdo/callback',
+    },
+    {
+        'name': 'oschina',
+        'client_class': OSChinaOAuth20,
+        'token_url': 'https://www.oschina.net/action/openapi/token',
+        'user_info_url': 'https://www.oschina.net/action/openapi/user',
+        'token_response': {'access_token': TEST_ACCESS_TOKEN, 'token_type': 'bearer', 'expires_in': 3600},
+        'redirect_uri': 'http://localhost:8000/auth/oschina/callback',
+    },
+]
+
 LOCALHOST_URL = 'http://localhost:8000'
 DEV_URL = 'http://dev.example.com'
 APP_URL = 'http://app.example.org'
@@ -30,12 +85,10 @@
 SECURE_APP_URL = 'https://app.example.org'
 SECURE_IP_URL = 'https://192.168.1.100:8443'
 
-# Callback paths
 AUTH_PATH = '/auth'
 CALLBACK_PATH = '/callback'
 OAUTH_CALLBACK_PATH = '/oauth2/callback'
 
-# Test URIs
 HTTP_URIS = [
     f'{LOCALHOST_URL}{CALLBACK_PATH}',
     f'{DEV_URL}{AUTH_PATH}/callback',
@@ -51,6 +104,47 @@
 ]
 
 
+@pytest.fixture
+def fastapi_app():
+    """Create FastAPI app for testing."""
+    app = FastAPI()
+
+    @app.get('/')
+    async def root():
+        return {'message': 'OAuth2 Test App'}
+
+    return app
+
+
+def mock_oauth_token_response(respx_mock, provider_config: dict, status_code: int = 200):
+    """Mock OAuth token endpoint response for a provider."""
+    return respx_mock.post(provider_config['token_url']).mock(
+        return_value=httpx.Response(status_code, json=provider_config['token_response'])
+    )
+
+
+def setup_oauth_callback_route(app: FastAPI, provider_config: dict, oauth_dependency):
+    """Setup OAuth callback route for testing."""
+    callback_path = f'/auth/{provider_config["name"]}/callback'
+
+    @app.get(callback_path)
+    async def oauth_callback_handler(access_token_state=Depends(oauth_dependency)):
+        token, state = access_token_state
+        return {'provider': provider_config['name'], 'access_token': token, 'state': state}
+
+    return callback_path
+
+
+def assert_oauth_error_response(response, expected_error: str, expected_status: int = 400):
+    """Assert OAuth error response has correct format."""
+    assert response.status_code == expected_status
+    data = response.json()
+    if 'detail' in data:
+        assert data['detail'] == expected_error
+    else:
+        assert data.get('error') == expected_error
+
+
 class TestFastAPIOAuth20Basic:
     """Basic tests for FastAPI OAuth2 integration using parametrized providers."""
 
@@ -126,8 +220,9 @@ async def test_callback_token_exchange_error_parametrized(self, provider_config,
         assert response.status_code == 500
         assert 'detail' in response.json()
 
-    def test_custom_exception_handler(self, github_client, fastapi_app):
+    def test_custom_exception_handler(self, fastapi_app):
         """Test custom exception handler for OAuth2 errors."""
+        github_client = GitHubOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
         github_oauth2_callback = FastAPIOAuth20(github_client, redirect_uri=f'{LOCALHOST_URL}/auth/github/callback')
 
         @fastapi_app.get('/auth/github/callback')
@@ -155,9 +250,10 @@ async def oauth2_error_handler(request: Request, exc: OAuth20AuthorizeCallbackEr
         assert data['error'] == 'access_denied'
         assert data['status_code'] == 400
 
-    def test_multiple_oauth_providers(self, github_client, google_client, fastapi_app):
+    def test_multiple_oauth_providers(self, fastapi_app):
         """Test multiple OAuth providers in the same app."""
         # Setup GitHub OAuth
+        github_client = GitHubOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
         github_oauth2_callback = FastAPIOAuth20(github_client, redirect_uri=f'{LOCALHOST_URL}/auth/github/callback')
 
         @fastapi_app.get('/auth/github/callback')
@@ -166,6 +262,7 @@ async def github_callback(access_token_state=Depends(github_oauth2_callback)):
             return {'provider': 'github', 'access_token': token, 'state': state}
 
         # Setup Google OAuth
+        google_client = GoogleOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
         google_oauth2_callback = FastAPIOAuth20(google_client, redirect_uri=f'{LOCALHOST_URL}/auth/google/callback')
 
         @fastapi_app.get('/auth/google/callback')
@@ -297,8 +394,9 @@ async def test_token_exchange_errors(self, provider_config, http_status, fastapi
 class TestFastAPIOAuth20Integration:
     """Integration tests for FastAPI OAuth2."""
 
-    def test_oauth_dependency_creation(self, github_client):
+    def test_oauth_dependency_creation(self):
         """Test OAuth dependency creation with different parameters."""
+        github_client = GitHubOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
         # Basic OAuth dependency
         oauth_dep = FastAPIOAuth20(github_client)
         assert oauth_dep.client == github_client
@@ -308,8 +406,9 @@ def test_oauth_dependency_creation(self, github_client):
         oauth_dep_custom = FastAPIOAuth20(github_client, redirect_uri=custom_redirect)
         assert oauth_dep_custom.client == github_client
 
-    def test_multiple_apps_same_provider(self, github_client):
+    def test_multiple_apps_same_provider(self):
         """Test the same OAuth provider in multiple FastAPI apps."""
+        github_client = GitHubOAuth20(client_id=TEST_CLIENT_ID, client_secret=TEST_CLIENT_SECRET)
         app1 = FastAPI()
         app2 = FastAPI()
 
diff --git a/tests/test_oauth20.py b/tests/test_oauth20.py
index 47e2d07..ae738dc 100644
--- a/tests/test_oauth20.py
+++ b/tests/test_oauth20.py
@@ -33,6 +33,7 @@ def oauth_client():
         client_secret='test_client_secret',
         authorize_endpoint='https://example.com/oauth/authorize',
         access_token_endpoint='https://example.com/oauth/token',
+        userinfo_endpoint='https://example.com/oauth/userinfo',
         refresh_token_endpoint='https://example.com/oauth/refresh',
         revoke_token_endpoint='https://example.com/oauth/revoke',
         default_scopes=['read', 'write'],
@@ -60,6 +61,7 @@ def test_oauth_base_initialization_minimal():
         client_secret='test_secret',
         authorize_endpoint='https://example.com/auth',
         access_token_endpoint='https://example.com/token',
+        userinfo_endpoint='https://example.com/userinfo',
     )
 
     assert client.client_id == 'test_id'
@@ -78,6 +80,7 @@ def test_oauth_base_initialization_with_basic_auth():
         client_secret='test_secret',
         authorize_endpoint='https://example.com/auth',
         access_token_endpoint='https://example.com/token',
+        userinfo_endpoint='https://example.com/userinfo',
         token_endpoint_basic_auth=True,
         revoke_token_endpoint_basic_auth=True,
     )
@@ -187,6 +190,7 @@ async def test_get_access_token_with_basic_auth():
         client_secret='test_secret',
         authorize_endpoint='https://example.com/auth',
         access_token_endpoint='https://example.com/token',
+        userinfo_endpoint='https://example.com/userinfo',
         token_endpoint_basic_auth=True,
     )
 
@@ -237,6 +241,7 @@ async def test_refresh_token_missing_endpoint():
         client_secret='test_secret',
         authorize_endpoint='https://example.com/auth',
         access_token_endpoint='https://example.com/token',
+        userinfo_endpoint='https://example.com/userinfo',
     )
 
     with pytest.raises(RefreshTokenError, match='refresh token address is missing'):
@@ -288,6 +293,7 @@ async def test_revoke_token_missing_endpoint():
         client_secret='test_secret',
         authorize_endpoint='https://example.com/auth',
         access_token_endpoint='https://example.com/token',
+        userinfo_endpoint='https://example.com/userinfo',
     )
 
     with pytest.raises(RevokeTokenError, match='revoke token address is missing'):
@@ -353,22 +359,19 @@ def test_get_json_result_invalid_json():
         OAuth20Base.get_json_result(mock_response, err_class=AccessTokenError)
 
 
-def test_abstract_method():
-    """Test that get_userinfo is properly abstract."""
-    with pytest.raises(TypeError):
-        OAuth20Base(
-            client_id='test',
-            client_secret='test',
-            authorize_endpoint='https://example.com/auth',
-            access_token_endpoint='https://example.com/token',
-        )
-
-
-def test_oauth_base_inheritance():
-    """Test that OAuth20Base is properly abstract."""
-    from abc import ABC
+def test_concrete_implementation():
+    """Test that OAuth20Base can be instantiated directly."""
+    client = OAuth20Base(
+        client_id='test',
+        client_secret='test',
+        authorize_endpoint='https://example.com/auth',
+        access_token_endpoint='https://example.com/token',
+        userinfo_endpoint='https://example.com/userinfo',
+    )
 
-    assert issubclass(OAuth20Base, ABC)
+    assert client.client_id == 'test'
+    assert client.client_secret == 'test'
+    assert client.userinfo_endpoint == 'https://example.com/userinfo'
 
 
 @pytest.mark.asyncio
@@ -379,6 +382,7 @@ async def test_get_userinfo_implementation():
         client_secret='test',
         authorize_endpoint='https://example.com/auth',
         access_token_endpoint='https://example.com/token',
+        userinfo_endpoint='https://example.com/userinfo',
     )
 
     result = await client.get_userinfo('test_token')