@flagly/sdk

Lightweight JavaScript and Node.js SDK for evaluating Flagly feature flags.

📦 Installation

Using npm:

npm install @flagly/sdk

Using yarn:

yarn add @flagly/sdk

Using pnpm:

pnpm add @flagly/sdk

🚀 Quick Start

import { FlaglyClient } from '@flagly/sdk';

const client = new Flagly({
  apiKey: 'flg_dev_xxxxx',
});

//sdk initialization
await client.init();

// Get single flag
const country = await client.getValue('country', 'IN');

// Get all flags
const flags = await client.getAllFlags();

⚙️ Configuration

new FlaglyClient({
  apiKey: string;       // Required
  apiHost?: string;     // Optional (default: http://localhost:4000/v1)
});

📚 API Reference

getAllFlags()

Returns all evaluated flags.

const flags = await client.getAllFlags();

getValue(key, defaultValue)

Returns a single flag value.

• If flag exists → returns evaluated value
• If flag disabled → returns defaultValue
• If flag missing → returns defaultValue

const theme = await client.getValue('theme', 'light');

🛡 Error Handling

The SDK throws clear errors in these cases:

• Invalid API key (401)
• Revoked API key (403)
• Invalid apiHost configuration
• Network failures (if no cache available)

Example:

try {
  await client.getAllFlags();
} catch (error) {
  console.error(error.message);
}

⚡ Features

• Bulk flag evaluation
• In-memory caching (TTL-based)
• Graceful fallback
• TypeScript support
• Lightweight and dependency-minimal

🧠 How It Works

• SDK fetches all flags from /v1/evaluate
• Flags are cached in memory
• Cache refreshes automatically after TTL
• SDK always returns a value (fallback-safe)

🛠 Requirements

• Node.js 16+

📄 License

MIT