Rate Limit SDK

Just playing...

Install

Install the package using npm:

npm install libsql-rate-limit

Usage

import { rateLimiter } from "libsql-rate-limit";

async function exampleUsage() {
  try {
    const result = await rateLimiter.limit({
      key: "user-123", // Unique identifier for the rate limit
      limit: 5, // Maximum number of requests allowed
      window: 60000, // Time window in milliseconds (60 seconds in this case)
    });

    if (result.success) {
      console.log("Request allowed");
      console.log(`Remaining requests: ${result.remaining}`);
    } else {
      console.log("Rate limit exceeded");
      console.log(`Try again in ${result.reset} ms`);
    }
  } catch (error) {
    console.error("Rate limiting error:", error);
  }
}

exampleUsage();

Custom Configuration

If you need to use a custom configuration, you can create a new rate limiter instance:

import { createRateLimiter } from "libsql-rate-limit";

const customRateLimiter = createRateLimiter({
  url: "libsql://your-database.turso.io",
  authToken: "your-auth-token",
});

// Use customRateLimiter.limit() as in the basic usage example

Configuration

The SDK can be configured using environment variables or by passing a configuration object to createRateLimiter.

Environment Variables

• LIBSQL_URL: The URL of your libSQL database (e.g., libsql://your-database.turso.io or file:./your-local.db)
• LIBSQL_AUTH_TOKEN: The authentication token for your libSQL database (if using a remote db)

If no environment variables are detected, the SDK defaults to using a local SQLite file at ./rate-limit.db.

Configuration Object

When using createRateLimiter, you can pass a configuration object that includes any of the properties from the Config interface of @libsql/client. The most commonly used properties are:

interface RateLimitConfig {
  url?: string;
  authToken?: string;
  // Other properties from @libsql/client's Config interface can be included as needed
}

If url is not provided in the config or environment variables, it defaults to 'file:./rate-limit.db'.

API

rateLimiter.limit(options: RateLimitOptions)

Check and update the rate limit for a given key.

• options.key: Unique identifier for the rate limit
• options.limit: Maximum number of requests allowed
• options.window: Time window in milliseconds

Returns a Promise<RateLimitResult>:

interface RateLimitResult {
  success: boolean; // Whether the request is allowed
  limit: number; // The maximum number of requests allowed
  remaining: number; // The number of requests remaining in the current window
  reset: number; // The number of milliseconds until the limit resets
}

createRateLimiter(config: RateLimitConfig)

Create a new RateLimiter instance with custom configuration.