Cache & Queue

Two simpler but essential modules for production applications. Cache gives you sub-millisecond key-value storage at the edge. Queue lets you offload work to background jobs with automatic retries.

Cache

Globally replicated key-value cache with TTL support, atomic counters, and bulk operations. Data is replicated globally for low-latency reads from any edge location.

What you can build with Cache

Session storage — Store user sessions with automatic expiry
Rate limiting — Atomic counters to track request rates per user/IP
Feature flags — Store and update feature flags without redeploying
Computed results — Cache expensive database queries or API responses
View counters — Atomic increment for page views, likes, votes
Shopping carts — Temporary cart data with TTL expiry

Basic operations

// Set a value (with optional TTL in seconds)
await sdk.cache.set('user:123', { name: 'Jane', plan: 'pro' }, { ttl: 3600 })

// Set with metadata
await sdk.cache.set('session:abc', sessionData, {
  ttl: 1800,
  metadata: { userId: '123', device: 'mobile' },
})

// Get a value (null if not found or expired)
const user = await sdk.cache.get('user:123')

// Check existence
const exists = await sdk.cache.has('user:123')

// Delete
await sdk.cache.delete('user:123')

// Set with TTL
err = client.Cache.Set(ctx, "user:123", userData, 3600)

// Get
var user User
found, err := client.Cache.Get(ctx, "user:123", &user)

// Check existence
exists, err := client.Cache.Has(ctx, "user:123")

// Delete
err = client.Cache.Delete(ctx, "user:123")

# Set with TTL
await client.cache.set("user:123", user_data, ttl=3600)

# Get
user = await client.cache.get("user:123")

# Check existence
exists = await client.cache.has("user:123")

# Delete
await client.cache.delete("user:123")

Bulk operations

Efficiently get, set, or delete multiple keys in a single round-trip:

// Get many
const values = await sdk.cache.getMany(['user:1', 'user:2', 'user:3'])
// { 'user:1': {...}, 'user:2': {...}, 'user:3': null }

// Set many
await sdk.cache.setMany({
  'user:1': { name: 'Alice' },
  'user:2': { name: 'Bob' },
  'user:3': { name: 'Carol' },
}, { ttl: 3600 })

// Delete many
await sdk.cache.deleteMany(['user:1', 'user:2', 'user:3'])

List keys

// List all keys with a prefix
const keys = await sdk.cache.keys({ prefix: 'session:' })
// ['session:abc', 'session:def', 'session:ghi']

// List with metadata
const entries = await sdk.cache.list({ prefix: 'session:' })
// [{ key: 'session:abc', metadata: { userId: '123' } }, ...]

Atomic counters

Increment or decrement values atomically. Perfect for rate limiting, view counts, and voting:

// Increment (creates key with value 1 if it doesn't exist)
const newCount = await sdk.cache.increment('views:post-123')
// 1, 2, 3, ...

// Increment by a specific amount
const newCount = await sdk.cache.increment('views:post-123', 5)

// Use for rate limiting
async function checkRateLimit(userId: string, limit: number) {
  const key = `ratelimit:${userId}:${Math.floor(Date.now() / 60000)}`
  const count = await sdk.cache.increment(key)

  if (count === 1) {
    // First request in this minute window -- set TTL
    await sdk.cache.expire(key, 60)
  }

  return count <= limit
}

Set expiry on existing key

await sdk.cache.expire('session:abc', 1800) // 30 minutes from now

Flush all cache

await sdk.cache.flush() // Delete everything -- use with caution

Complete example: session store

import { AerostackClient } from '@aerostack/sdk'

const { sdk } = new AerostackClient({ projectId, apiKey })

async function createSession(userId: string, device: string) {
  const sessionId = crypto.randomUUID()

  await sdk.cache.set(`session:${sessionId}`, {
    userId,
    device,
    createdAt: Date.now(),
    lastActive: Date.now(),
  }, {
    ttl: 86400, // 24 hours
    metadata: { userId, device },
  })

  return sessionId
}

async function getSession(sessionId: string) {
  const session = await sdk.cache.get(`session:${sessionId}`)
  if (!session) return null

  // Refresh TTL on access
  await sdk.cache.set(`session:${sessionId}`, {
    ...session,
    lastActive: Date.now(),
  }, { ttl: 86400 })

  return session
}

async function destroySession(sessionId: string) {
  await sdk.cache.delete(`session:${sessionId}`)
}

async function getUserSessions(userId: string) {
  const entries = await sdk.cache.list({ prefix: 'session:' })
  return entries.filter(e => e.metadata?.userId === userId)
}

Complete example: feature flags

async function setFlag(name: string, value: boolean, metadata?: Record<string, any>) {
  await sdk.cache.set(`flag:${name}`, { enabled: value, ...metadata })
}

async function getFlag(name: string): Promise<boolean> {
  const flag = await sdk.cache.get(`flag:${name}`)
  return flag?.enabled ?? false
}

async function getAllFlags() {
  const keys = await sdk.cache.keys({ prefix: 'flag:' })
  const values = await sdk.cache.getMany(keys)
  return Object.fromEntries(
    keys.map(k => [k.replace('flag:', ''), values[k]?.enabled ?? false])
  )
}

// Usage
await setFlag('new-checkout', true)
await setFlag('dark-mode', true, { rollout: 50 })

if (await getFlag('new-checkout')) {
  // Show new checkout flow
}

Cache API reference

Method	Signature	Returns
`sdk.cache.get`	`(key: string) => Promise<T \| null>`	Cached value or null
`sdk.cache.set`	`(key: string, value: any, opts?: { ttl?, metadata? }) => Promise<void>`	Nothing
`sdk.cache.delete`	`(key: string) => Promise<void>`	Nothing
`sdk.cache.has`	`(key: string) => Promise<boolean>`	Boolean
`sdk.cache.getMany`	`(keys: string[]) => Promise<Record<string, T>>`	Map of key to value
`sdk.cache.setMany`	`(entries: Record<string, any>, opts?) => Promise<void>`	Nothing
`sdk.cache.deleteMany`	`(keys: string[]) => Promise<void>`	Nothing
`sdk.cache.keys`	`(opts?: { prefix? }) => Promise<string[]>`	Array of keys
`sdk.cache.list`	`(opts?: { prefix? }) => Promise<{ key, metadata }[]>`	Keys with metadata
`sdk.cache.increment`	`(key: string, amount?: number) => Promise<number>`	New value
`sdk.cache.expire`	`(key: string, ttl: number) => Promise<void>`	Nothing
`sdk.cache.flush`	`() => Promise<void>`	Nothing

Queue

Background job processing with configurable retries, delays, and status tracking. Jobs are durably stored and guaranteed to execute at least once.

What you can build with Queue

Email notifications — Send welcome emails, password resets, order confirmations
PDF generation — Generate invoices, reports, or certificates in the background
Batch imports — Process CSV uploads row by row without blocking the request
Image processing — Resize, crop, or optimize uploaded images
Webhook delivery — Retry failed webhook deliveries with exponential backoff
Scheduled tasks — Delay job execution for reminders, follow-ups, or scheduled reports
Data sync — Sync data between Aerostack and external systems

Enqueue a job

// Simple job
await sdk.queue.enqueue('send-welcome-email', {
  userId: 'user-123',
  email: 'jane@example.com',
  name: 'Jane',
})

// Job with options
await sdk.queue.enqueue('generate-report', {
  reportType: 'monthly',
  month: '2026-03',
  userId: 'user-123',
}, {
  delaySeconds: 60,  // Wait 1 minute before processing
  maxRetries: 5,     // Retry up to 5 times on failure
})

err = client.Queue.Send(ctx, "send-welcome-email", payload, aerostack.QueueOptions{
    DelaySeconds: 0,
    MaxRetries:   3,
})

await client.queue.send(
    "send-welcome-email",
    {"userId": "user-123", "email": "jane@example.com"},
    delay_seconds=0,
    max_retries=3
)

Check job status

const job = await sdk.queue.getJob(jobId)
// { id, type, status, payload, attempts, maxRetries, createdAt, scheduledAt, completedAt }

Status	Description
`pending`	Waiting to be processed (or delayed)
`processing`	Currently being executed
`completed`	Successfully finished
`failed`	All retries exhausted
`cancelled`	Manually cancelled

List jobs

const jobs = await sdk.queue.listJobs({
  type: 'send-welcome-email',   // optional filter
  status: 'pending',             // optional filter
  limit: 50,
})

Cancel a job

await sdk.queue.cancelJob(jobId)

Complete example: email notification pipeline

import { AerostackClient } from '@aerostack/sdk'

const { sdk } = new AerostackClient({ projectId, apiKey })

// Enqueue from your API handler
async function onUserSignup(user: { id: string, email: string, name: string }) {
  // Send welcome email immediately
  await sdk.queue.enqueue('send-email', {
    template: 'welcome',
    to: user.email,
    data: { name: user.name },
  })

  // Send onboarding tip after 24 hours
  await sdk.queue.enqueue('send-email', {
    template: 'onboarding-tip-1',
    to: user.email,
    data: { name: user.name },
  }, { delaySeconds: 86400 })

  // Send follow-up after 3 days
  await sdk.queue.enqueue('send-email', {
    template: 'onboarding-tip-2',
    to: user.email,
    data: { name: user.name },
  }, { delaySeconds: 259200 })
}

// Process jobs in your worker
async function processEmailJob(job: { type: string, payload: any }) {
  const { template, to, data } = job.payload

  // Send via your email provider
  await sendEmail({ template, to, data })

  // Log in database
  await sdk.db.query(
    'INSERT INTO email_log (id, template, recipient, sent_at) VALUES (?, ?, ?, ?)',
    [crypto.randomUUID(), template, to, Date.now()]
  )
}

Complete example: batch CSV import

async function importCSV(userId: string, csvContent: string) {
  const rows = parseCSV(csvContent)

  // Enqueue each row as a separate job (can process in parallel)
  for (const row of rows) {
    await sdk.queue.enqueue('import-row', {
      userId,
      data: row,
    }, { maxRetries: 3 })
  }

  // Track the import
  await sdk.db.query(
    'INSERT INTO imports (id, user_id, total_rows, status, created_at) VALUES (?, ?, ?, ?, ?)',
    [crypto.randomUUID(), userId, rows.length, 'processing', Date.now()]
  )
}

Queue API reference

Method	Signature	Returns
`sdk.queue.enqueue`	`(type: string, payload: any, opts?: { delaySeconds?, maxRetries? }) => Promise<{ jobId: string }>`	Job ID
`sdk.queue.getJob`	`(jobId: string) => Promise<Job>`	Job details
`sdk.queue.listJobs`	`(opts?: { type?, status?, limit? }) => Promise<Job[]>`	Array of jobs
`sdk.queue.cancelJob`	`(jobId: string) => Promise<void>`	Nothing