A few days ago, I introduced Playground API—a zero-config, stateful mock REST API designed to solve a huge frontend headache: mock APIs like standard JSONPlaceholder that instantly discard your , , and state changes.
Playground API changed that by introducing zero-login per-session sandboxing, giving developers real data persistence in their browser without database setups or account creation.
Since then, based on awesome feedback from the community, I've shipped a massive v2.0 update packed with features designed specifically for modern frontend development, UI edge-case testing, and E2E automation! ⚡ Here is a breakdown of what's new and how you can use Playground API to level up your development workflow. 🆕 What’s New in Playground API v2.0? ⏱️
1.
Network Delay Simulation ( & ) Testing skeleton loaders, loading spinners, and debounced inputs on local is notoriously difficult because mock APIs respond almost instantaneously (10–30ms).
Now, you can force Playground API to simulate network latency directly from your code or request headers: Or via request header: 🚨
2.
HTTP Error Simulation ( & ) Want to verify how your app handles a , , or without breaking your server code?
You can now inject arbitrary HTTP error responses on-demand: Or via request header: 🔗
3.
Relational Sub-Resources & Nested Filtering Building master-detail views or user profile dashboards?
Playground API now natively supports relational queries and nested sub-resource routing out-of-the-box: 🔍
4.
Universal Full-Text Search () & Dynamic Sorting () Quickly search and sort through baseline data merged with your custom session sandbox edits: 🛡️
5.
E2E Test Suite Ready () & Programmatic Reset While cookies () handle state persistence smoothly in standard browsers, automated E2E test runners (Playwright, Cypress) and strict Incognito / Safari policies often block cross-site cookies.
Playground API v2 introduces Header-Based Identity Fallback and Programmatic Session Resets: Send in header to maintain isolated sandbox state across test runs.
Call to wipe all custom session mutations and revert back to a clean global baseline before each test suite! 📦
6.
Multi-Format Collection & Schema Downloads Need to import mock endpoints into your favorite API client?
You can now download full specs directly from the documentation UI or API: 📄 OpenAPI 3.0 Spec () 🚀 Postman Collection v2.1 () 🐶 Bruno API Collection () 💜 Insomnia Collection () 💻
- 9-Language Live Code Generators The built-in documentation runner now instantly generates ready-to-use code snippets in 9 popular languages and libraries: cURL, Node.js Fetch, Axios, Python, Go, Swift, Kotlin, Rust, and PHP. ⚛️ Updated React Example: Skeleton Loader + Error Handling + Delay Simulation Here’s a full React component demonstrating how easily you can test loading spinners, error states, and CRUD mutations: 📊 Summary: v1 vs v2 Comparison Feature Playground API v1 🚀 Playground API v2 State Persistence ✅ Per-session Sandbox ✅ Per-session Sandbox Network Latency Simulation ❌ Instant only ✅ / Header Error Status Simulation ❌ None ✅ / Header Relational Querying ❌ Base routes only ✅ , Search & Sorting ❌ None ✅ & E2E & Incognito Support ⚠️ Cookies only ✅ Header Schema Downloads ❌ None ✅ OpenAPI, Postman, Bruno, Insomnia Code Generators ⚡ Basic JavaScript ⚡ 9 Languages (Go, Rust, Swift, etc.) 🔗 Try It Out & Support the Project Playground API is 100% free, zero-config, and requires no registration: 🌐 Live App & Interactive Docs: https://playground-api-xi.vercel.app/ ⭐ GitHub Repository: github.com/nileshcodehub/playground_api If you find Playground API helpful for your projects, demos, or E2E tests, leaving a ⭐ on GitHub would mean the world!
What features would you like to see next?
Drop a comment below! 👇