Offline Queue

The offline queue lets you save failed requests and replay them when connectivity is restored.

Storage Backends

Backend	Environment	Persistence
MemoryStorage	Node.js, Browser, Edge	Lost on process exit
LocalStorageBackend	Browser	Survives page reloads
Custom	Any	Implement QueueStorage interface

Usage

import { OfflineQueue, MemoryStorage, LocalStorageBackend } from 'fetch-smartly';

// Node.js
const queue = new OfflineQueue(new MemoryStorage());

// Browser (persists across reloads)
const queue = new OfflineQueue(new LocalStorageBackend());

Enqueue Failed Requests

import { fetchWithRetry, NetworkError } from 'fetch-smartly';

try {
  await fetchWithRetry({ url: 'https://api.example.com/submit', method: 'POST', body: '{"data":1}' });
} catch (error) {
  if (error instanceof NetworkError) {
    queue.enqueue({ url: 'https://api.example.com/submit', method: 'POST', body: '{"data":1}' });
    console.log('Request queued for later');
  }
}

Replay When Online

const successes = await queue.replay(async (entry) => {
  const res = await fetch(entry.url, {
    method: entry.method,
    headers: entry.headers,
    body: entry.body,
  });
  if (!res.ok) throw new Error(`HTTP ${res.status}`);
});

console.log(`${successes} replayed, ${queue.size} still queued`);

Successful entries are removed automatically. Failed entries remain for the next replay attempt.

Custom Storage

import type { QueueStorage, QueueEntry } from 'fetch-smartly';

class RedisStorage implements QueueStorage {
  getAll(): QueueEntry[] { /* ... */ }
  add(entry: QueueEntry): void { /* ... */ }
  remove(id: string): void { /* ... */ }
  clear(): void { /* ... */ }
}

const queue = new OfflineQueue(new RedisStorage());

API

Method	Description
queue.enqueue(options)	Add a request to the queue
queue.getAll()	Get all queued entries
queue.size	Number of queued requests
queue.remove(id)	Remove a specific entry
queue.replay(executor)	Replay all, returns success count
queue.clear()	Remove all entries