MQTT.Agent - open protocol for AI agents

Platform Comparison

CloudSignal vs Pusher
Open Protocol vs Proprietary WebSockets

Pusher Channels is great for classic chat, but its proprietary protocol locks you in and its best-effort delivery breaks under unreliable networks. CloudSignal gives you the same real-time experience on an open protocol with real QoS guarantees.

Feature-by-Feature Comparison

An honest side-by-side. We call out where Pusher has the stronger story.

Feature
CloudSignal
Pusher
Protocol
MQTT is portable. Pusher Channels code only runs on Pusher
MQTT (ISO/IEC 20922 open standard) over TCP or WebSockets
Proprietary Pusher protocol over WebSockets
Pricing model
Pusher bills on peak concurrent connections and daily message counts
Flat monthly tiers with all features included
Per-message and per-connection tiers with sandbox limits
Free tier
Both have free entry points. The shape of the limits differs
Unlimited time, no credit card, 3 MQTT users
Sandbox plan with 200K messages per day and 100 connections
Delivery guarantees
Pusher is fire-and-forget. If a client misses a message during a reconnect, it is gone
MQTT QoS 0, 1, and 2 for at-most-once, at-least-once, and exactly-once
Best-effort delivery, no QoS levels, no exactly-once semantics
Offline support
If your users go offline, MQTT will resume cleanly. Pusher requires you to layer your own catch-up
Persistent sessions, retained messages, and QoS 1/2 queueing
No native offline queue. Channels assume a live connection
Security model
Pusher's auth lives in your application code. CloudSignal enforces in the broker before bytes move
Broker-enforced ACL rule sets with identity-bound topics
Private and presence channels gated by an HTTP auth endpoint in your app
AI integration
For AI chat or agent communication, this is a real category difference
AI Transport for Vercel AI SDK with streaming and offline resume
No first-party AI streaming product
Presence and typing indicators
Pusher's presence channel API is more turnkey for chat-style features
Built on MQTT primitives via retained messages and last-will
Dedicated presence channels with a clean SDK API
Beams push notifications
Pusher Beams is a separate product but covers more platforms today
PWA push notifications included; native APNs/FCM on the roadmap
Pusher Beams supports iOS, Android, and web push
Vendor lock-in
Pusher Channels code does not port. MQTT code does
None. MQTT clients run unchanged on any broker
Proprietary protocol. Migrating away requires client and server rewrites

Why the Differences Matter

The Pusher SDK is pleasant to use. The protocol underneath is where the long-term engineering trade-offs live.

Open Protocol, Zero Lock-In

Pusher Channels uses a proprietary WebSocket protocol. Migrating away means rewriting client SDKs, server handlers, and channel auth endpoints. CloudSignal speaks MQTT, a 30-year-old ISO/IEC standard. If you ever want to move to another broker or self-host, your client code does not change.

Real Delivery Guarantees

Pusher is fire-and-forget. If a subscriber misses a message during a network drop, it is gone. CloudSignal supports MQTT QoS 0, 1, and 2, plus persistent sessions and retained messages, so reconnecting clients catch up automatically. For chat, notifications, and AI streaming, this is the difference between a polished feature and a flaky one.

Security at the Broker Layer

Pusher's private and presence channels authenticate by calling an HTTP endpoint in your application. If that endpoint has a bug, the security guarantee is gone. CloudSignal enforces ACL rules inside the broker, validated against topic patterns before a byte leaves the network.

AI Transport Out of the Box

CloudSignal ships AI Transport, a drop-in transport for the Vercel AI SDK that streams tokens over MQTT and resumes after disconnects. With Pusher you would build that streaming and resume layer yourself on top of an unguaranteed transport.

How to Decide

The right choice depends on whether your use case needs guaranteed delivery and an open protocol.

Choose CloudSignal when…

  • You are building AI chat, agent communication, or anything that needs reliable streaming
  • You want an open protocol with no client rewrite if you ever migrate
  • You need real delivery guarantees, not best-effort messages
  • You want broker-enforced ACL rule sets, not application-layer channel auth
  • You want flat monthly pricing without per-connection ceilings

Choose Pusher when…

  • You are shipping a classic chat or live-update feature and want a turnkey presence API
  • You need cross-platform push notifications today via Pusher Beams
  • Your team is already deep in Pusher SDKs and migration cost is high
  • You are happy with best-effort delivery and do not need QoS guarantees
  • You prefer a WebSocket-only product without MQTT in the stack
Open Protocol. Guaranteed Delivery. AI-Native.

Ready to Try CloudSignal?

Start on the free tier in minutes. MQTT over WebSockets works from any browser, and QoS gives you real delivery guarantees from day one.

Questions about migrating from Pusher?