Symulate

Open Source & Free Usage

Use Symulate SDK completely free with three flexible modes

Symulate SDK is Open Source (MIT License)

Full SDK functionality available completely free. Choose the mode that fits your needs.

Three Usage Modes

🎯

Faker Mode

100% free, no API key needed

✅ Zero setup
✅ Deterministic data
✅ Perfect for CI/CD
🚀

BYOK Mode

Bring your own OpenAI key

✅ AI-realistic data
✅ Local persistence
✅ No vendor lock-in
💼

Platform Mode

Full enterprise features

✅ Cloud hosting
✅ Team collaboration
✅ Branch isolation

Mode 1: Faker Mode

Perfect for CI/CD pipelines, testing, and basic prototyping. No API keys required!

Installation

npm install @symulate/sdk

Configuration

import { configureSymulate, defineEndpoint, m } from '@symulate/sdk';

// That's it! No API key needed
configureSymulate({
  generateMode: 'faker', // Uses Faker.js for deterministic data
});

// Define schema and endpoint
const UserSchema = m.object({
  id: m.uuid(),
  name: m.person.fullName(),
  email: m.email(),
  avatar: m.internet.avatar(),
});

export const getUsers = defineEndpoint({
  path: '/api/users',
  method: 'GET',
  schema: UserSchema,
  mock: { count: 10 },
});

// Use it - completely free!
const users = await getUsers();

💡 Perfect for:

  • • CI/CD pipelines (deterministic, reproducible data)
  • • Unit and integration tests
  • • Quick prototyping without any setup
  • • Learning and experimentation

Mode 2: BYOK (Bring Your Own Key)

Get AI-powered realistic data with your own OpenAI API key. No Symulate account needed!

Setup

  1. Get an OpenAI API key at platform.openai.com/api-keys
  2. Install Symulate SDK: npm install @symulate/sdk
  3. Add your key to .env.local
# .env.local
OPENAI_API_KEY=sk-your-key-here

Configuration

import { configureSymulate, defineCollection, m, type Infer } from '@symulate/sdk';

// Configure with your OpenAI API key
configureSymulate({
  openaiApiKey: process.env.OPENAI_API_KEY, // Your OpenAI key
  generateMode: 'ai', // Use AI generation
  // persistence defaults to "local" automatically!
});

// Define a collection with full CRUD operations
const ProductSchema = m.object({
  id: m.uuid(),
  name: m.string(),
  price: m.number({ min: 10, max: 1000 }),
  category: m.string(),
  brand: m.string(),
  inStock: m.boolean(),
});

export type Product = Infer<typeof ProductSchema>;

export const products = defineCollection<Product>({
  name: 'products',
  basePath: '/api/products',
  schema: ProductSchema,
  seedCount: 20,
  seedInstruction: 'Generate realistic e-commerce products',
});

// Use it - full CRUD with AI-generated data
const { data } = await products.list();
await products.create({
  name: 'New Item',
  price: 29.99,
  category: 'Electronics',
  brand: 'TechCo',
  inStock: true
});
await products.update('id', { price: 24.99 });
await products.delete('id');

✨ What you get:

  • • AI-realistic, contextual data generation
  • • Full CRUD operations with stateful collections
  • • Local persistence (localStorage in browser, filesystem in Node.js)
  • • Delay and error simulation
  • • Flexible response schemas with meta fields
  • • No vendor lock-in - it's your data, your infrastructure

💰 Cost: OpenAI API charges (~$0.001 per generation with gpt-4o-mini). Essentially free for most use cases - expect $0.01-0.05 per development session.

Feature Comparison

FeatureFaker ModeBYOKPlatform
Cost100% Free~$0.001/genFrom $49/mo
API Key Required❌ NoneYour OpenAI keyPlatform key
Data QualityBasic (valid)✨ AI-realistic✨ AI-realistic
CRUD Collections✅✅✅
Endpoints✅✅✅
PersistenceMemory/Local✅ Local (auto)✅ Cloud + Local
Delay Simulation✅✅✅
Error Simulation✅✅✅
Isolated Demos❌❌✅
Team Collaboration❌❌✅
Custom Domains❌❌✅
SupportCommunityCommunityPriority

Quick Start Guide

🎯 Option 1: Faker Mode (Zero Setup)

npm install @symulate/sdk
import { configureSymulate } from '@symulate/sdk';

configureSymulate({
  generateMode: 'faker', // That's it!
});

🚀 Option 2: BYOK with OpenAI

  1. 1. Get OpenAI API key
  2. 2. npm install @symulate/sdk
  3. 3. Configure:
configureSymulate({
  openaiApiKey: process.env.OPENAI_API_KEY,
  generateMode: 'ai',
  // Persistence auto-defaults to "local"!
});

Available Features

📦 Collections

Full CRUD operations with stateful data, pagination, filtering, and sorting

🔌 Endpoints

REST API mocking with GET, POST, PUT, PATCH, DELETE support

💾 Persistence

localStorage (browser) and filesystem (Node.js) with automatic fallback

⏱️ Delay Simulation

Simulate network latency to test loading states

⚠️ Error Simulation

Test error handling with conditional failures and AI-generated error responses

📊 Meta Fields

Flexible response schemas with pagination and aggregates (avg, sum, min, max, count)

Complete Examples

Check out the examples directory in the SDK repository:

  • byok-example.ts - Complete BYOK setup with collections
  • flexible-response-schema-example.ts - Custom response formats with meta fields
  • delay-simulation-example.ts - Network latency simulation
  • error-simulation-example.ts - Error handling patterns

When to Upgrade to Platform

Consider upgrading to Symulate Platform when you need:

🏢 Agency & Client Work

Branch isolation lets you create client-specific demos (e.g., demo.clientname.com) with separate data per branch

👥 Team Collaboration

Share mock data across your team with cloud-hosted persistence and collaborative workspaces

☁️ Zero Infrastructure

No need to set up local persistence or manage OpenAI keys - it just works

🎯 Priority Support

Get help from our team when you need it, with dedicated support channels

Ready to upgrade?

Start with our free Platform tier (20K one-time AI tokens) or check out our pricing plans.

Start Free Trial View Pricing

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