Feature Deep Dive2 min read•2026-09-20

Shareable Sandbox URLs & Cross-Device Mobile QR Sync in Playground API

Learn how to share stateful mock API sandboxes with team members and sync live prototype data instantly to mobile devices using QR codes.

Nilesh Kumar

Creator of Playground API

Shareable Sandbox URLs & Cross-Device Mobile QR Sync in Playground API

When sharing a frontend prototype with a client, designer, or QA engineer, you run into a classic problem:

The mock data you created (custom blog posts, uploaded avatars, updated todos) is stored only in your local browser session.
When someone else opens the prototype link, they see an empty or generic base state.
Testing on a physical mobile device requires manually recreating the test state from scratch.

Playground API solves this with Shareable Sandbox URLs (?_sandbox=<uuid>) and Cross-Device Mobile QR Sync!

1. How Shareable Sandbox URLs Work

Every session sandbox can be exported or linked via a unique UUID:

Terminal

https://playground.nileslabs.com/posts?_sandbox=a4b7-9cde-f123

When someone opens your React app with this sandbox parameter, the client simply forwards ?_sandbox=... in API requests (or passes the X-Playground-Identity header). Both users now share the exact same stateful dataset in real time!

2. Instant Cross-Device Mobile QR Sync

Inside the Playground API documentation sidebar:

Click the "Share Sandbox" button.
A modal displays a dynamic QR code containing your active sandbox session URL.
Scan the QR code with your iPhone or Android camera.
Your mobile browser immediately loads the web app connected to your exact test data!

3. Forwarding Sandbox Identifiers in React

typescript

// Helper to extract ?_sandbox query parameter and attach to API calls

export function getApiHeaders(): Record<string, string> {

const urlParams = new URLSearchParams(window.location.search);

const sandboxId = urlParams.get('_sandbox');

return sandboxId ? { 'X-Playground-Identity': sandboxId } : {};

}

// Fetching shared posts

const res = await fetch('https://playground.nileslabs.com/posts', {

headers: getApiHeaders(),

});

Test sandbox cloning, copy share links, and generate sync QR codes directly in the documentation:

👉 https://playground.nileslabs.com/docs/sharing

Conclusion

Collaborate on frontend prototypes seamlessly and test on real mobile devices with zero backend deployment using Playground API!

Tags:#react #webdev #javascript #mobile

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Try Playground API in Your Own App

Stateful mock REST & GraphQL API with private sandbox overlays.

Quickstart Guide Open Interactive Studio

Shareable Sandbox URLs & Cross-Device Mobile QR Sync in Playground API

When sharing a frontend prototype with a client, designer, or QA engineer, you run into a classic problem:

The mock data you created (custom blog posts, uploaded avatars, updated todos) is stored only in your local browser session.

When someone else opens the prototype link, they see an empty or generic base state.

Testing on a physical mobile device requires manually recreating the test state from scratch.

Playground API solves this with Shareable Sandbox URLs (?_sandbox=<uuid>) and Cross-Device Mobile QR Sync!

1. How Shareable Sandbox URLs Work

Every session sandbox can be exported or linked via a unique UUID:

Terminal

https://playground.nileslabs.com/posts?_sandbox=a4b7-9cde-f123

3. Forwarding Sandbox Identifiers in React

typescript

// Helper to extract ?_sandbox query parameter and attach to API calls

export function getApiHeaders(): Record<string, string> {

const urlParams = new URLSearchParams(window.location.search);

const sandboxId = urlParams.get('_sandbox');

return sandboxId ? { 'X-Playground-Identity': sandboxId } : {};

}

// Fetching shared posts

const res = await fetch('https://playground.nileslabs.com/posts', {

headers: getApiHeaders(),

});