Authentication Method Comparison
Session-Based
Stores sessions on the server and passes session ID via cookies
- Simple implementation
- Can be invalidated immediately
- Requires session sharing when scaling servers
JWT (Token-Based)
Client holds a signed token
- No server state needed
- Ideal for microservices
- Difficult to handle token theft
Build Your Own vs Auth Services
Recommended: Use an Auth Service
Authentication is a security-sensitive area. We recommend using a proven auth service, especially when starting out.
Building your own can easily introduce security vulnerabilities and adds significant maintenance burden.
Recommended Auth Services
Clerk
Auth service optimized for React. Includes social login, MFA, and organization management.
View Guide →NextAuth.js
Full-stack auth solution for Next.js. Supports 50+ OAuth providers.
View Guide →Auth0
Enterprise-grade auth platform. RBAC, SSO, and MFA built-in.
View Guide →Firebase Auth
Google's free auth service. Supports both web and mobile apps.
View Guide →Looking for Supabase Auth? Check the Supabase Guide for auth integration instructions.
FastAPI + JWT Example (Reference)
If you must build your own, refer to the structure below:
from fastapi import FastAPI, Depends, HTTPException
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from passlib.context import CryptContext
from datetime import datetime, timedelta
# Password hashing
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
# JWT configuration
SECRET_KEY = "your-secret-key" # Use environment variables in production!
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")
def verify_password(plain_password, hashed_password):
return pwd_context.verify(plain_password, hashed_password)
def create_access_token(data: dict):
to_encode = data.copy()
expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
to_encode.update({"exp": expire})
return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
async def get_current_user(token: str = Depends(oauth2_scheme)):
try:
payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
user_id: str = payload.get("sub")
if user_id is None:
raise HTTPException(status_code=401, detail="Invalid token")
return user_id
except JWTError:
raise HTTPException(status_code=401, detail="Invalid token")Caution: Production Requires More Considerations
- HTTPS is required
- Manage secret keys with environment variables
- Implement Refresh Tokens
- Rate Limiting
- Login attempt throttling
Which service should you choose?
- React SPA → Clerk (quick start)
- Next.js → NextAuth (full-stack)
- Enterprise/RBAC → Auth0
- Mobile + Web → Firebase Auth
- Using Supabase → Supabase Auth