Mock OAuth / OIDC Provider

A free, hosted mock OAuth 2.0 & OpenID Connect identity provider for local development, E2E testing, and CI/CD pipelines.

Live at oauth.sdk42.com

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Hi,

I'm Aarne, founder of YourOpinion.is — the best free AI-native survey platform :)

I built this mock OAuth provider because my team and I were tired of dealing with real identity providers during development. Google, Facebook, GitHub — they're all great for production, but terrible for local testing. Rate limits, anti-bot protections, managing test accounts, keeping secrets out of git... it was slowing us down.

So I created this. It's intentionally permissive — accepts any client_id, any client_secret, any redirect_uri. Perfect for development and automated testing.

We use it daily at YourOpinion.is, and I figured other developers face the same pain. So here it is, open source and free to use. No signup, no rate limits, no hassle.

— Aarne

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How it works?

Screen.Recording.2026-02-13.at.11.18.57.mov

Why?

Real identity providers (Google, Facebook, GitHub) are great for production but painful for development:

• Rate limits and anti-automation measures break E2E tests
• Every developer needs their own OAuth app or test account
• Secrets can't be committed to source control
• CI/CD pipelines need extra credential management

This mock provider solves all of that. It's intentionally permissive — any client_id, client_secret, and redirect_uri works.

Features

• Stable test users — Same PIN always generates the same set of users
• No API quotas — Unlimited requests, no rate limits
• Instant setup — No registration, no API keys, no OAuth app config
• OIDC-compliant — Standard discovery, token, and userinfo endpoints
• CI/CD friendly — Configurations are safe to commit to source control
• E2E-ready — Users have data-testid attributes for Playwright/Cypress

Quick Start

Point your app at the discovery document:

https://oauth.sdk42.com/.well-known/openid-configuration

Or configure manually:

Endpoint	URL
Authorization	https://oauth.sdk42.com/authorize
Token	https://oauth.sdk42.com/token
UserInfo	https://oauth.sdk42.com/userinfo
JWKS	https://oauth.sdk42.com/.well-known/jwks.json

Use any client_id and client_secret — they're all accepted.

How Users Work

On the authorization screen, you're presented with 9 generated users. Enter a numeric PIN to seed the user generation:

• With a PIN: First 7 users are deterministic (same PIN = same users every time), last 2 are random
• Without a PIN: All 9 users are randomly generated

This lets your team agree on shared test identities:

• PIN 345 → Frederik Abshire is always the admin
• PIN 345 → Dejon King-Pagac is always the blocked user

E2E Testing

Users have data-testid="test-user-{1-9}" attributes. For automated tests:

• Use a test-case-specific PIN for stable, deterministic users
• Pick data-testid="test-user-9" for a random user (works even if a PIN is set)

Self-Hosting

pnpm install
pnpm dev

The app is a standard Next.js project. Deploy anywhere that supports Next.js (Vercel, Cloudflare, Docker, etc.).

Note: The RSA keys in src/lib/jwk.ts are committed intentionally — this is a mock provider with only fake data. Do not reuse these keys for anything else.

License

MIT