Core REST Resource

125 Baseline Fixtures

Todos REST API & Data Model

Task item records with completion status. 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 Todos Record Explorer

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

Limit:

ID	Status	Task Title	Assignee (user_id)	State
No records found matching query.

Page 1 of 1

Todo 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 (1-200) or local-<uuid>.	1
user_id	number \| string	Required	Foreign key referencing assigned users.id.	1
title	string	Required	Task description checklist text.	"delectus aut autem"
completed	boolean	Required	Completion status boolean. Filterable via ?completed=true\|false.	false
created_at	string	Optional	ISO 8601 creation timestamp.	"2026-03-01T09:15:00.000Z"
_sandbox	'created' \| 'updated'	Optional	Session mutation indicator added to modified records.	"created"

Entity Relationships & Nested Sub-Resources

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

belongsTo

User

FK: user_id

GET /todos/:id/user

Assigned user profile owning this task.

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 useTodos(page = 1, limit = 10, search = '') {

return useQuery({

queryKey: ['todos', 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/todos?${params}`, {

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

});

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

return res.json();

});

}

// 2. Stateful Optimistic Create Mutation

export function useCreateTodo() {

const queryClient = useQueryClient();

return useMutation({

mutationFn: async (newRecord) => {

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

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: () => {

Custom Collections

PreviousComments Resource

NextCustom Collections