date: 2025-08-12
topics: [frontend, dsa, nextjs, authentication, next-auth]
day: 26
Day 26 – Implementing Multi-Provider Authentication with NextAuth
✅ What I Worked On
- Set up authentication in a Next.js project using NextAuth.
- Integrated Google OAuth, GitHub OAuth, and a custom credentials provider.
- Configured
.env.local for storing API keys and secrets.
- Implemented
jwt and session callbacks to attach a uid to the session.
- Solved three linked list problems for DSA practice:
- Add Two Numbers – Implemented addition using linked lists to simulate digit-by-digit summation.
- Remove Nth Node from End – Used a two-pointer technique to achieve single-pass removal.
- Merge Two Sorted Lists – Merged two sorted linked lists into one without creating new nodes.
📚 What I Learned
- How to configure multiple authentication providers in
NEXT_AUTH_CONFIG.
- Using callbacks to customize the JWT and session objects.
- How OAuth apps on GitHub and Google require correct callback URLs.
❌ Blockers
- Initially got stuck with the
client_id is required error for GitHub because my .env variable names didn’t match my code.
- Spent some time debugging why
process.env values were coming up undefined — solved it by restarting the dev server after editing .env.local.
🧠 Reflection
Today I did Next.js authentication setup.
Now I have three working sign-in methods — Google, GitHub, and custom credentials — all feeding into a unified session object.
The main lesson: 90% of "NextAuth is broken" problems are just environment variable typos or callback URL mismatches.
Next up, I want to secure API routes and create a polished login UI so the experience is smooth for real users.
💻 pow: