Stop Polling. Start Scrolling.

Connect your IoT sensor to your mobile app.
In minutes.

CrossFeed is a real-time JSON relay service that connects 2 endpoints or thousands. No backend to build. No infrastructure to manage. Just a persistent connection that works.

Get Early Access →
📡 Raspberry Pi your garage ENDPOINT 📱 iPhone App anywhere in the world ENDPOINT CrossFeed JSON Relay WSS WSS {json} {json} Both sides connect outbound. Works behind any NAT, any firewall. No port forwarding. No VPN. No dynamic DNS.
The Difference

You just want your sensor data on your phone.

Here's what it takes today — and what it takes with CrossFeed.

The traditional way

  1. Spin up a cloud server
  2. Install and configure a WebSocket or MQTT broker
  3. Obtain and manage TLS certificates
  4. Configure firewall rules and open ports
  5. Set up dynamic DNS or a static IP
  6. Write reconnection and error handling logic
  7. Build an authentication layer
  8. Handle NAT traversal on the device side
  9. Set up monitoring and uptime alerts
  10. Maintain it all. Forever.
Weeks of setup. Weekends of maintenance.

With CrossFeed

  1. pip install crossfeed on your device
  2. Import CrossFeedKit in your iOS app
  3. Connect, join a channel, send JSON
Under 5 minutes. Nothing to maintain.
Dead Simple Integration

This is all the code you need.

Native libraries for Swift (iOS/macOS) and Python (Raspberry Pi, Linux, macOS). Async by default. Production-ready reconnection built in.

Device Side — Python
from crossfeed import CrossFeedConnection async with CrossFeedConnection(url) as conn: await conn.join("my-channel", secret, role="server") while True: reading = sensor.read() await conn.relay({"temp": reading}) await asyncio.sleep(5)
App Side — Swift
import CrossFeedKit let conn = CrossFeedConnection() conn.onRelay = { from, payload in // payload["temp"] has your sensor reading updateUI(payload) } conn.connect(to: url, connectionId: "my-channel", secret: clientSecret, role: .client)
Under The Hood

A smart pipe that stays out of your way.

Your endpoints connect to CrossFeed. They talk. We relay — with presence, metadata, encryption, and authentication baked in. No message queues, no databases, no rules engines. Just real-time data, flowing.

⇄

NAT Traversal, Solved

Both device and app connect outbound. Works behind any router, any firewall, any carrier-grade NAT. No port forwarding needed.

⚡

Real-Time Presence

Know instantly when your device comes online or drops off. First-class presence notifications with disconnect reasons, not an afterthought bolt-on.

📋

Endpoint Metadata

Attach rich JSON metadata to connections. Your app discovers device capabilities. Your device knows who's watching. Like business cards for endpoints.

🔒

Shared Secret Auth

Simple, effective channel authentication. Server and client secrets keep uninvited guests out. No certificate management, no OAuth flows.

↔

Flexible Topologies

1:1 device-to-app. 1:N one device, many viewers. N:N peer mesh. Server-Client or Peer mode. Your architecture, not ours.

∞

Unlimited Messages

No per-message pricing. Ever. Your sensor can send every second, every 100ms, whatever your project needs. One flat monthly rate.

🔐

End-to-End Encryption

Zero-knowledge relay. Your payload is encrypted before it leaves your device and decrypted on arrival. The relay routes it but can never read it.

📦

Stream Anything

Audio, video, data — native binary payloads with zero encoding overhead. CrossFeed is the full data path, not just a signaling channel.

📂

Large Payload Transfer

Resumable chunked transfers of binary data with progress reporting. Sync folders, send firmware updates, stream recordings. Pause and pick up where you left off.

Built For Makers

What will you connect?

If it runs Python and has WiFi, CrossFeed can get its data to your phone. Here are some ideas.

🌡

Home Sensors

Temperature, humidity, water flow, air quality. Stream readings from a Raspberry Pi to your iPhone dashboard in real time.

Raspberry Pi + iOS
🏡

Smart Home Controls

Garage door openers, irrigation controllers, pet feeders. Send commands from your phone to your devices from anywhere.

ESP32 + iOS/Android
📊

Remote Dashboards

System monitoring, server metrics, weather stations. Stream data from any machine to a mobile dashboard with live updates.

Linux + SwiftUI
🎥

Camera & Media

Trigger recordings, receive motion alerts, stream status from security cameras and media devices.

Pi Zero W + iOS
🌱

Garden & Aquaponics

Monitor soil moisture, pH levels, grow lights. Keep tabs on your garden or fish tank from across town.

Arduino + Mobile
🛠

Workshop Tools

CNC status, 3D print progress, power monitoring. Know when your job is done without hovering over the machine.

Any Device + Any App
Simple Pricing

No per-message charges. No surprises.

Flat monthly pricing. Your sensor can send as often as it needs to. We'll never punish high-frequency data.

Free
$0/mo
Prototype and experiment
1 channel · 2 endpoints
1,000 messages/day
Maker
$5/mo
One real project, shipped
1 channel · 10 endpoints
Unlimited messages
Pro
$20/mo
Multiple projects in production
5 channels · 50 each
Unlimited messages
Business
$99/mo
Shipping a real product
25 channels · 250 each
Unlimited messages

All plans include unlimited messages. Pricing is per channel, not per message.

Coming Soon

Be first in line.

CrossFeed is live in production and battle-tested. Public access is opening soon. Tell us about your project.

Early adopters get priority access and founding-member pricing.