# FastAPI OAuthlib

***

**1. Access Token Introspection**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI, Request

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key")

@app.post("/token/introspection")
async def token_introspection(request: Request, token: str = Form(...)):
    return await oauth2.introspect_token(request, token)
```

**2. OAuth 2.0 Implicit Grant**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    authorization_code="implicit",
    authorization_endpoint="https://example.com/authorize",
)

@app.get("/auth/implicit")
async def implicit_grant(request: Request, redirect_uri: str = Query(...)):
    return await oauth2.authorize_implicit(request, redirect_uri)
```

**3. OAuth 2.0 Authorization Code Grant**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    authorization_code="code",
    authorization_endpoint="https://example.com/authorize",
    token_endpoint="https://example.com/token",
)

@app.get("/auth/code")
async def code_grant(request: Request):
    return await oauth2.authorize_code(request)
```

**4. OAuth 2.0 Client Credentials Grant**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    authorization_code="credentials",
    token_endpoint="https://example.com/token",
)

@app.post("/auth/credentials")
async def credentials_grant(request: Request):
    return await oauth2.authorize_credentials(request)
```

**5. OAuth 2.0 Password Credentials Grant**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    authorization_code="password",
    token_endpoint="https://example.com/token",
)

@app.post("/auth/password")
async def password_grant(request: Request):
    return await oauth2.authorize_password(request)
```

**6. OAuth 2.0 Refresh Token Grant**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    authorization_code="refresh_token",
    token_endpoint="https://example.com/token",
)

@app.post("/auth/refresh")
async def refresh_grant(request: Request):
    return await oauth2.authorize_refresh(request)
```

**7. OAuth 2.0 Bearer Token Validation**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key")

@app.get("/protected")
async def protected_resource(request: Request):
    return await oauth2.verify_token(request)
```

**8. OAuth 2.0 Scope Validation**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key")

@app.get("/protected")
async def protected_resource(request: Request):
    scopes = await oauth2.verify_token(request)
    if "read" in scopes:
        return "Read access granted"
```

**9. OAuth 2.0 User Info Endpoint**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    userinfo_endpoint="https://example.com/userinfo",
)

@app.get("/userinfo")
async def userinfo(request: Request):
    return await oauth2.get_userinfo(request)
```

**10. OAuth 2.0 Redirect URI Validation**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    redirect_uris=["https://example.com/callback"],
)

@app.get("/auth/code")
async def code_grant(request: Request):
    if not oauth2.validate_redirect_uri(request):
        raise HTTPException(status_code=400, detail="Invalid redirect URI")
```

**11. OAuth 2.0 Client Metadata**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    secret_key="my-secret-key",
    client_metadata={"allowed_origins": ["https://example.com"]}
)

@app.get("/protected")
async def protected_resource(request: Request):
    if not oauth2.verify_client_metadata(request):
        raise HTTPException(status_code=400, detail="Invalid client metadata")
```

**12. OAuth 2.0 Token Introspection in Python**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key")

@app.post("/introspect")
async def token_introspect(request: Request, token: str = Form(...)):
    introspection_request = oauth2.introspection_endpoint(request, token)
    result = await introspection_request.send()
    return result.content
```

**13. OAuth 2.0 Authorization Code Flow**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI
from fastapi.responses import RedirectResponse

app = FastAPI()

oauth2 = OAuth2(authorization_endpoint="https://example.com/authorize")

@app.get("/auth/code")
async def authorization_code(request: Request):
    return oauth2.authorization_code(request)

@app.get("/callback")
async def oauth_callback(request: Request):
    code = request.query_params["code"]
    token = await oauth2.oauth_token(code)
    return RedirectResponse(url="/protected", status_code=302)
```

**14. OAuth 2.0 Resource Server**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key")

@app.get("/protected")
async def protected_resource(request: Request):
    if not oauth2.verify_bearer_token(request):
        raise HTTPException(status_code=401, detail="Invalid or expired token")
```

**15. OAuth 2.0 Client Credentials**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(token_endpoint="https://example.com/token")

@app.post("/auth/client")
async def client_credentials(request: Request):
    token = await oauth2.client_credentials(request)
    return token
```

**16. OAuth 2.0 Device Flow**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    authorization_endpoint="https://example.com/device/authorize",
    token_endpoint="https://example.com/device/token"
)

@app.get("/auth/device")
async def device_auth(request: Request):
    return oauth2.device_auth(request)
```

**17. OAuth 2.0 PKCE**

```python
from fastapi_oauth2 import OAuth2, PKCE
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    authorization_endpoint="https://example.com/authorize",
    token_endpoint="https://example.com/token",
    pkce=PKCE()
)

@app.get("/auth/code")
async def authorization_code(request: Request):
    code = oauth2.authorization_code(request)
    code_verifier = request.query_params["code_verifier"]
    return await oauth2.oauth_token(code, pkce_verifier=code_verifier)
```

**18. OAuth 2.0 Refresh Token**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(token_endpoint="https://example.com/token")

@app.post("/auth/refresh")
async def refresh_token(request: Request):
    token = await oauth2.refresh_token(request)
    return token
```

**19. OAuth 2.0 Custom Token Request**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    token_endpoint="https://example.com/token",
    extra_grant_types={
        "my_grant_type": "my_handler_function"
    }
)

async def my_handler_function(request: Request):
    # Your custom token request logic
    # For example, you can verify username and password and return access and refresh tokens
    access_token = "my_access_token"
    refresh_token = "my_refresh_token"
    return {"access_token": access_token, "refresh_token": refresh_token}
```

**20. OAuth 2.0 Token Introspection**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(introspection_endpoint="https://example.com/introspect")

@app.post("/introspect")
async def token_introspection(request: Request, token: str = Form(...)):
    result = await oauth2.introspection(token)
    return result
```

**21. OAuth 2.0 Client ID Verification**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(client_id="your_client_id")

@app.get("/protected")
async def protected_resource(request: Request):
    if not oauth2.verify_client_id(request):
        raise HTTPException(status_code=401, detail="Invalid or expired client ID")
```

**22. OAuth 2.0 Bearer Token Validation with Scopes**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key")

@app.get("/protected")
async def protected_resource(request: Request):
    scopes = await oauth2.verify_token(request)
    if "read" in scopes:
        return "Read access granted"
    raise HTTPException(status_code=403, detail="Insufficient scope")
```

**23. OAuth 2.0 Refresh Token Rotation**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key")

@app.post("/auth/refresh")
async def refresh_token(request: Request):
    new_access_token, new_refresh_token = await oauth2.refresh_token(request)
    return {"access_token": new_access_token, "refresh_token": new_refresh_token}
```

**24. OAuth 2.0 Custom User Info Endpoint**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    userinfo_endpoint="https://example.com/userinfo",
    userinfo_handler=lambda token: {
        "sub": "user1",
        "name": "John Doe",
        "email": "user1@example.com",
    }
)

@app.get("/userinfo")
async def userinfo(request: Request):
    userinfo = await oauth2.userinfo(request)
    return userinfo
```

**25. OAuth 2.0 JWT Token Validation**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key", issuer="https://example.com")

@app.get("/protected")
async def protected_resource(request: Request):
    await oauth2.verify_token(request)
```

**26. OAuth 2.0 API Gateway Integration**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    authorization_endpoint="https://example.com/authorize",
    token_endpoint="https://example.com/token",
    api_gateway_header="x-api-key"
)

@app.get("/protected")
async def protected_resource(request: Request):
    await oauth2.verify_token(request)
```

**27. OAuth 2.0 Resource Server with Multiple Scopes**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key", scopes={"read": "read access", "write": "write access"})

@app.get("/protected")
async def protected_resource(request: Request):
    scopes = await oauth2.verify_token(request)
    if "read" in scopes:
        return "Read access granted"
    elif "write" in scopes:
        return "Write access granted"
```

**28. OAuth 2.0 Client Credentials with JWT Access Tokens**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    token_endpoint="https://example.com/token",
    grant_type="client_credentials",
    token_type="jwt"
)

@app.get("/protected")
async def protected_resource(request: Request):
    await oauth2.verify_token(request)
```

**29. OAuth 2.0 Authorization Code Grant with PKCE**

```python
from fastapi_oauth2 import OAuth2, PKCE
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    authorization_endpoint="https://example.com/authorize",
    token_endpoint="https://example.com/token",
    pkce=PKCE()
)

@app.get("/auth/code")
async def authorization_code(request: Request):
    code = oauth2.authorization_code(request)
    code_verifier = request.query_params["code_verifier"]
    return await oauth2.oauth_token(code, pkce_verifier=code_verifier)
```

**30. OAuth 2.0 Refresh Token Rotation with JWT Access Tokens**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    token_endpoint="https://example.com/token",
    refresh_token_endpoint="https://example.com/refresh",
    token_type="jwt"
)

@app.post("/auth/refresh")
async def refresh_token(request: Request):
    new_access_token = await oauth2.refresh_token(request)
    return {"access_token": new_access_token}
```

**31. OAuth 2.0 Bearer Token Validation with Scopes and Claims**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(secret_key="my-secret-key", claims={"role": "admin"})

@app.get("/protected")
async def protected_resource(request: Request):
    claims = await oauth2.verify_token(request)
    if claims["role"] == "admin":
        return "Admin access granted"
```

**32. OAuth 2.0 Client Credentials Grant with JWT Access Tokens and Custom Token Claims**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    token_endpoint="https://example.com/token",
    grant_type="client_credentials",
    token_type="jwt",
    token_claims={"role": "client"}
)

@app.get("/protected")
async def protected_resource(request: Request):
    await oauth2.verify_token(request)
```

**33. OAuth 2.0 Token Introspection with JWT Access Tokens**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    introspection_endpoint="https://example.com/introspect",
    token_type="jwt"
)

@app.post("/introspect")
async def token_introspection(request: Request, token: str = Form(...)):
    result = await oauth2.introspection(token)
    return result
```

**34. OAuth 2.0 Resource Server with Multiple Authorization Servers**

```python
from fastapi_oauth2 import OAuth2, MultipleOAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2_a = OAuth2(secret_key="my-secret-key-a", authorization_endpoint="https://example.com/authorize-a")
oauth2_b = OAuth2(secret_key="my-secret-key-b", authorization_endpoint="https://example.com/authorize-b")

multiple_oauth2 = MultipleOAuth2([oauth2_a, oauth2_b])

@app.get("/protected")
async def protected_resource(request: Request):
    await multiple_oauth2.verify_token(request)
```

**35. OAuth 2.0 Proxy**

```python
from fastapi_oauth2 import OAuth2, ProxyOAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2_a = OAuth2(secret_key="my-secret-key-a", authorization_endpoint="https://example.com/authorize-a")
oauth2_b = OAuth2(secret_key="my-secret-key-b", authorization_endpoint="https://example.com/authorize-b")

proxy_oauth2 = ProxyOAuth2([oauth2_a, oauth2_b], path="protected")

@app.get("/protected")
async def protected_resource(request: Request):
    await proxy_oauth2.verify_token(request)
```

**36. OAuth 2.0 API Gateway Integration with Authorization Code**

```python
from fastapi_oauth2 import OAuth2
from fastapi import FastAPI

app = FastAPI()

oauth2 = OAuth2(
    authorization_endpoint="https://example.com/authorize",
    token_endpoint="https://example.com/token",
    api_gateway_query="code"
)

@app.get("/protected")
async def protected_resource(request: Request):
    await oauth2.verify_token(request)
```