Core REST Resource

25 Baseline Fixtures

Users REST API & Data Model

User profile records with names, usernames, emails, address details, and avatar seeds. Full CRUD simulation supporting persistent writes, relationship traversal, full-text filtering, and copy-on-write isolation per visitor session.

Full CRUD (GET, POST, PUT, PATCH, DELETE)Copy-on-Write Session OverlayRelational Sub-ResourcesFull-Text Search & Pagination

Live Users Record Explorer

Live queries executed directly against GET /api/v1/users.

Limit:

ID	Profile	Username	Email	Location / Company	State
No records found matching query.

Page 1 of 1

User Entity Schema & Field Dictionary

Exact property definitions, data types, nullability, and nested structures.

Field	Type	Required	Description	Example
id	number \| string	Required	Primary key. Integer (1-25) for baseline seed records or local-<uuid> for session records.	1
name	string	Required	Full display name of user.	"Leanne Graham"
username	string	Required	Unique handle identifier used for deterministic SVG avatars and login.	"Bret"
email	string	Required	Unique verified email address.	"Sincere@april.biz"
phone	string	Optional	Contact telephone number.	"+1-770-555-0123"
website	string	Optional	Personal website or domain.	"hildegard.org"
address	object	Optional	Nested address object with street, city, zipcode, and geo coordinates.	{ city: "Gwenborough" }
company	object	Optional	Nested employer company details.	{ name: "Romaguera-Crona" }
_sandbox	'created' \| 'updated'	Optional	Session mutation indicator added automatically on write operations.	"created"

Entity Relationships & Nested Sub-Resources

Access related entities without multiple round trips using hierarchical REST sub-resource paths.

hasMany

Posts

FK: user_id

GET /users/:id/posts

All articles authored by this user profile.

hasMany

Todos

FK: user_id

GET /users/:id/todos

Task checklist items assigned to this user.

hasMany

Comments

FK: email

GET /users/:id/comments

Discussion comments authored by this user email.

Copy-On-Write Sandbox Architecture

How stateful mutations persist during your test session without requiring database locks or affecting other developers.

Baseline Read-Only Layer

Every session starts with pristine baseline fixtures (25 users, 100 posts, 500 comments, 200 todos). These records are never permanently modified or locked.

Per-Visitor Overlay Tier

When you call POST, a local-<uuid> record is spawned. PUT / PATCH modifies your private overlay, and DELETE tags a tombstone marker.

Atomic Reset & Zero Lock

Sessions run in parallel with 100% isolation. A single call to POST /api/v1/sandbox/reset purges the overlay and restores clean initial data in <5ms.

Production Client Integration Recipes

Tested integration patterns for React Query, TypeScript Fetch, Axios, Python, and cURL:

// React 18+ with TanStack Query v5 & Optimistic Mutation

import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';

// 1. Fetch Paginated Collection

export function useUsers(page = 1, limit = 10, search = '') {

return useQuery({

queryKey: ['users', page, limit, search],

queryFn: async () => {

const params = new URLSearchParams({ page: String(page), limit: String(limit) });

if (search) params.set('q', search);

const res = await fetch(https://playground.nileslabs.com/api/v1/users?${params}`, {

credentials: 'include', // Includes visitor sandbox session

});

if (!res.ok) throw new Error('Failed to fetch users');

return res.json();

});

}

// 2. Stateful Optimistic Create Mutation

export function useCreateUser() {

const queryClient = useQueryClient();

return useMutation({

mutationFn: async (newRecord) => {

const res = await fetch('https://playground.nileslabs.com/api/v1/users', {

method: 'POST',

headers: { 'Content-Type': 'application/json' },

credentials: 'include',

body: JSON.stringify(newRecord),

});

if (!res.ok) throw new Error('Create failed');

return res.json();

onSuccess: () => {

// Invalidate query to merge new sandbox record at top of collection

queryClient.invalidateQueries({ queryKey: ['users'] });

});

}

Interactive API Consoles (Users)

Execute direct live requests against the sandbox API endpoints:

List All Users

Retrieve a paginated list of users. Results merge shared global user records with session sandbox overlays (newly created users appear at the top).

GET

response.json

{

// Click "Send" above to execute this request against the live server.

}

Get Single User

Retrieve a single user by ID. Supports plain integer IDs for global records (e.g. 1) and string IDs formatted as local-<uuid> for sandbox records.

GET

response.json

{

// Click "Send" above to execute this request against the live server.

}

Create New User

Create a new session sandbox user record. Returns a local-<uuid> formatted ID with _sandbox: "created". Capped at 30 custom created records per session.

POST

response.json

{

// Click "Send" above to execute this request against the live server.

}

Replace User (PUT)

Replace an existing user record in the session overlay. Global baseline records remain untouched for all other developers.

PUT

response.json

{

// Click "Send" above to execute this request against the live server.

}

Partial User Update (PATCH)

Partially update specific profile fields of a user record in your session overlay.

PATCH

response.json

{

// Click "Send" above to execute this request against the live server.

}

Delete User

Remove a user record from your session view. The underlying global baseline record is unaffected for other users.

DELETE

response.json

{

// Click "Send" above to execute this request against the live server.

}

Get User Posts Sub-Resource

Retrieve all blog posts authored by a specific user with full pagination, search query, and sorting support.

GET

response.json

{

// Click "Send" above to execute this request against the live server.

}

Get User Todos Sub-Resource

Retrieve all task todos assigned to a specific user, with optional completion status filtering.

GET

response.json

{

// Click "Send" above to execute this request against the live server.

}

Core REST Overview

Posts Collection

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