Introduction

What is App Config.json?

App Config.json is a modern configuration management platform that allows you to define, version, and deploy application settings across all environments — from local development to production — with zero downtime.

Instead of scattering configuration across environment variables, hardcoded files, and deployment pipelines, App Config.json provides a single source of truth for your entire application's configuration, accessible through a simple JSON interface and powerful SDKs.

How It Works

App Config.json operates on a simple but powerful model:

1. Define your configuration schema Create a config.json file that defines your app's settings, including defaults, validation rules, and environment-specific overrides.
2. Push to the App Config.json platform Use our CLI, dashboard, or API to push your configuration. Changes are immediately validated and versioned.
3. Load in your application Use one of our SDKs to fetch and apply configurations. Updates are pushed to your running instances in real-time without restarts.

Key Features

Prerequisites

Before getting started, make sure you have the following:

• An App Config.json account (free tier available)
• Node.js 18+ or Python 3.9+ or Go 1.21+
• Access to an API key from your dashboard settings
• Basic familiarity with JSON and environment configuration

Quick Start

Get your first configuration up and running in under 5 minutes. This guide walks you through creating an account, installing the SDK, and loading your first config.

Step 1: Create an Account

Head over to appconfig.json and sign up for a free account. Once logged in, navigate to your Dashboard and create a new project.

Step 2: Install the SDK

Install the SDK for your preferred language:

# Using npm
npm install @appconfig/sdk

# Using yarn
yarn add @appconfig/sdk

# Using pnpm
pnpm add @appconfig/sdk

# Using pip
pip install appconfig

# Using poetry
poetry add appconfig

go get github.com/appconfig/sdk-go/v3

# Install the CLI tool
curl -fsSL https://cli.appconfig.json/install | bash

Step 3: Initialize Your App

Initialize the SDK with your API key. We recommend storing your key in an environment variable:

import { AppConfig } from '@appconfig/sdk';

// Initialize the client
const config = new AppConfig({
  apiKey: process.env.APP_CONFIG_KEY,
  projectId: 'my-awesome-app',
  environment: process.env.NODE_ENV || 'development',
});

// Connect to the realtime sync channel
await config.connect();
console.log('Connected to App Config.json');

Step 4: Load Your First Config

Fetch and use your configuration values. The SDK handles caching, validation, and realtime updates automatically:

// Load the full configuration
const settings = await config.get('app');

console.log(settings.app_name);        // "my-awesome-app"
console.log(settings.version);         // "3.0.0"
console.log(settings.features);        // { realtime_sync: true, ... }

// Listen for realtime updates
config.onUpdate((changes) => {
  console.log(`Config updated: ${changes.keys.join(', ')}`);
  // Apply new configuration...
});

Installation

Here's a more detailed guide on installing and configuring the App Config.json SDK for each supported language.

Node.js / TypeScript

npm install @appconfig/sdk

# For TypeScript, types are included
# No additional @types package needed

Python

pip install appconfig

# Optional: async support
pip install appconfig[async]

Go

go get github.com/appconfig/sdk-go/v3@latest

System Requirements

Configuration Schema

App Config.json uses a structured JSON schema to define your application's configuration. Below is the complete schema reference with all available fields and their types.

Basic Configuration

{
  "app_name": "my-awesome-app",
  "version": "3.0.0",
  "environment": "production",
  "debug": false,
  "port": 3000,
  "database": {
    "host": "db.appconfig.json",
    "port": 5432,
    "name": "myapp_production",
    "ssl": true
  },
  "features": {
    "realtime_sync": true,
    "max_retries": 3,
    "timeout_ms": 5000,
    "beta_ui": false
  },
  "endpoints": {
    "api": "https://api.appconfig.json/v3",
    "cdn": "https://cdn.appconfig.json"
  }
}

Schema Reference

Below is the complete field reference for the configuration schema: