MQTT.Agent - open protocol for AI agents

CloudSignal vs PubNub

A PubNub Alternative Built on Open Standards

CloudSignal delivers real-time messaging on MQTT - an open ISO standard - with flat-rate pricing, broker-level security, and native AI transport. No proprietary SDKs required.

Feature Comparison

An honest, side-by-side look at what each platform offers.

Feature
CloudSignal
PubNub
Protocol
Open standard vs. vendor-specific protocol
MQTT (ISO/IEC 20922)
Proprietary SDK
Free tier
50,000 messages / month
Limited trial only
Starting price
$29 / month (Pro)
Pay-per-transaction + MAU fees
Pricing model
Flat-rate plans
Complex: messages + MAU + add-ons
Broker-level ACL
CloudSignal enforces topic permissions at the broker - not in application code
Offline message queuing
MQTT QoS 1/2 guarantees delivery after reconnection
Retained messages
AI Transport (Vercel AI SDK)
Vendor lock-in
None - standard MQTT clients
High - proprietary SDK required
WebSocket support
REST API bridge
Self-hosted option

Why Developers Choose CloudSignal

Four areas where CloudSignal meaningfully differs from PubNub.

Open Protocol, No Lock-in

CloudSignal is built on MQTT - an ISO/IEC standard used across industries from IoT to finance. Any MQTT-compatible client works out of the box. Migrate away at any time without rewriting your application.

Security at the Broker Level

Access control rules are enforced inside the broker itself, not as middleware in your application code. Topics are identity-bound, so a compromised client cannot publish to channels it was never authorized for.

Predictable Pricing

PubNub bills per transaction, per monthly active user, and per optional add-on. CloudSignal charges a flat monthly rate. Your bill does not spike when a feature goes viral.

AI-Native Transport

The CloudSignal AI Transport integrates directly with the Vercel AI SDK, streaming AI responses over MQTT in real time. No polling, no SSE workarounds - persistent bidirectional channels for every model interaction.

Making the Right Choice

Both platforms are mature products. The right choice depends on your team's priorities.

Choose CloudSignal if...

  • You need a standards-based protocol that works with existing MQTT clients and libraries
  • Cost predictability matters - fixed monthly plans instead of per-message billing
  • Security requirements demand ACL enforcement at the transport layer, not in application logic
  • You are building AI-powered chat, assistants, or streaming interfaces with the Vercel AI SDK
  • You want offline-first messaging with guaranteed delivery via MQTT QoS semantics
  • You need the option to self-host or move to a different provider without a full rewrite

Choose PubNub if...

  • You need a large set of enterprise-specific vertical solutions (healthcare, fintech, gaming) with pre-built compliance features
  • Your team is already deeply integrated with PubNub SDKs and the migration cost outweighs the benefits
  • You require serverless Functions (PubNub Functions) to run edge logic inside the messaging layer
  • You want the reassurance of a larger, more established vendor with a longer enterprise track record

Transparent Pricing at Every Scale

CloudSignal's plans are straightforward: a free tier with 50,000 messages per month, a $29/month Pro plan, and a $79/month Scale plan. No per-MAU charges, no per-transaction fees, no surprise bills at the end of the month.

Free
$0
50K messages/mo
Pro
$29/mo
5M messages/mo
Scale
$79/mo
Unlimited messages

Ready to Switch?

Start on the free tier - no credit card required. Your first 50,000 messages are on us.

Questions about migrating from PubNub?