Source: https://seerepo.com/r/nextauthjs/next-auth/built
Markdown source: https://seerepo.com/r/nextauthjs/next-auth/built.md
Description: next-auth is a TypeScript repo. It stores its data in MongoDB and Postgres and uses Supabase and Firebase. It has 55,839 written lines, with 96 test files.

# What is next-auth built with?

next-auth is a TypeScript repo. It stores its data in MongoDB and Postgres and uses Supabase and Firebase. It has 55,839 written lines, with 96 test files.

Read on November 2, 2026, at commit a1a16a5.

Repository: https://github.com/nextauthjs/next-auth

## Backend

### Data

- **[MongoDB](https://seerepo.com/uses/mongodb)**: 2 files · [packages/adapter-mongodb/src/index.ts, line 17](https://github.com/nextauthjs/next-auth/blob/a1a16a5a7780488c7449feece410033f445d0b31/packages/adapter-mongodb/src/index.ts#L17)
- **[Postgres](https://seerepo.com/uses/postgres)**: 2 files · [packages/adapter-neon/src/index.ts, line 24](https://github.com/nextauthjs/next-auth/blob/a1a16a5a7780488c7449feece410033f445d0b31/packages/adapter-neon/src/index.ts#L24)
- **[Supabase](https://seerepo.com/uses/supabase)**: 1 file · [packages/adapter-supabase/src/index.ts, line 17](https://github.com/nextauthjs/next-auth/blob/a1a16a5a7780488c7449feece410033f445d0b31/packages/adapter-supabase/src/index.ts#L17)

### Services

- **[Firebase](https://seerepo.com/uses/firebase)**: 1 file · [packages/adapter-firebase/src/index.ts, line 18](https://github.com/nextauthjs/next-auth/blob/a1a16a5a7780488c7449feece410033f445d0b31/packages/adapter-firebase/src/index.ts#L18)

## Other repos with a similar stack

- [n8n-io/n8n](https://seerepo.com/r/n8n-io/n8n/built): MongoDB, Postgres, Supabase · [Compare](https://seerepo.com/compare/n8n-io/n8n/vs/nextauthjs/next-auth)
- [ruvnet/ruflo](https://seerepo.com/r/ruvnet/ruflo/built): MongoDB, Postgres, Supabase · [Compare](https://seerepo.com/compare/nextauthjs/next-auth/vs/ruvnet/ruflo)
- [mem0ai/mem0](https://seerepo.com/r/mem0ai/mem0/built): MongoDB, Postgres, Supabase · [Compare](https://seerepo.com/compare/mem0ai/mem0/vs/nextauthjs/next-auth)
- [yangshun/tech-interview-handbook](https://seerepo.com/r/yangshun/tech-interview-handbook/built): Postgres, Supabase
- [Stirling-Tools/Stirling-PDF](https://seerepo.com/r/Stirling-Tools/Stirling-PDF/built): Postgres, Supabase
- [apache/superset](https://seerepo.com/r/apache/superset/built): MongoDB, Postgres

## Frequently asked questions

### What language is next-auth written in?

next-auth is written in TypeScript, with 55,839 written lines.

### What database does next-auth use?

next-auth stores its data in MongoDB and Postgres.

The proof: [packages/adapter-mongodb/src/index.ts, line 17](https://github.com/nextauthjs/next-auth/blob/a1a16a5a7780488c7449feece410033f445d0b31/packages/adapter-mongodb/src/index.ts#L17)

### What services does next-auth use?

next-auth uses Supabase and Firebase.

The proof: [packages/adapter-supabase/src/index.ts, line 17](https://github.com/nextauthjs/next-auth/blob/a1a16a5a7780488c7449feece410033f445d0b31/packages/adapter-supabase/src/index.ts#L17)

### Does next-auth have tests?

Yes. next-auth has 96 test files.

### Which repos have a stack like next-auth's?

The ones that share most of its stack: n8n-io/n8n, ruvnet/ruflo, and mem0ai/mem0.

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.