📦 @limitkit/memory

In-memory store and built-in rate limiting policies for LimitKit.

⚠ @limitkit/memory is only best suited for:

• ✅ Local development
• ✅ Testing environments
• ✅ Single-instance applications
• ✅ Prototyping and evaluation

Because all state is stored in-process, it does not scale across multiple instances.

For production and distributed systems, consider using Redis via @limitkit/redis.

⚡ Installation

npm install @limitkit/core @limitkit/memory

⚡ Quick Start

Set store: new InMemoryStore()

import { RateLimiter } from "@limitkit/core";
import { InMemoryStore, fixedWindow } from "@limitkit/memory";

const limiter = new RateLimiter({
  store: new InMemoryStore(),

  rules: [
    {
      name: "global",
      key: "global",
      policy: fixedWindow({
        window: 60,
        limit: 100,
      }),
    },
  ],
});

await limiter.consume(ctx);

• All rate limiting data is stored in memory.
• Each process maintains its own counters, so there are no shared states across processes.
• There are no network calls, thus the latency is very low (sub-ms)
• The states are cleared if the application restarts.

process memory → policy → decision

⚙️ Algorithms

@limitkit/memory includes optimized implementations of common rate limiting strategies.

You have to ensure all the policies use the algorithm functions below from @limitkit/memory

import { fixedWindow } from "@limitkit/memory";

Fixed Window

fixedWindow({ window: 60, limit: 100 })

Sliding Window

slidingWindow({ window: 60, limit: 100 })

Sliding Window Counter

slidingWindowCounter({ window: 60, limit: 100 })

Token Bucket

tokenBucket({ capacity: 100, refillRate: 5 })

Leaky Bucket

leakyBucket({ capacity: 100, leakRate: 5 })

GCRA (Generalized Cell Rate Algorithm)

gcra({ burst: 5, interval: 1 })