Networking · Fly

Private Networking That Just Works

Every app in your organization automatically joins a secure IPv6 mesh network (6PN). No config or absurdly complex inter-service auth. Just instant private connectivity between all your services.

Fly.io Networking in 5 Mins

Fly Domains Explained | .fly.dev, .internal, .flycast - YouTube

Fly Domains Explained | .fly.dev, .internal, .flycast Fly․io

Flycast: Private Services That Wake Up On Demand

Flycast gives your private services a special .flycast address that routes through Fly Proxy instead of direct Machine-to-Machine connections. This unlocks powerful features like waking up sleeping services when they're needed and load balancing across regions, all while staying completely private.

Services auto-start when called, auto-stop when idle (save money!)

Load balance private traffic across regions automatically

Connect services across different organizations

Works with clients that can't use standard DNS

Check out the Flycast Docs

Intelligent Load Balancing

Traffic automatically flows to the closest, least-loaded Machines. No manual configuration, just smart routing based on real-time metrics and geographic proximity.

Round-trip time (RTT) aware: Routes to closest Machines

Load-based routing: Avoids overloaded Machines

Configurable concurrency: Fine-tune limits per service

Dynamic traffic distribution across regions

Fly Proxy: Your Global Edge Network

The intelligent routing layer that gets requests where they need to go - fast. Fly Proxy handles everything from TLS termination to dynamic request routing across our global infrastructure.

Automatic TLS termination

Routes to closest, least-loaded Machines

Dynamic request routing with fly-replay

Machine autostop/autostart on traffic

HTTPS Without the Yak Shaving

Remember when you had to get an SSL cert and make it work before you could show anyone your app? Yeah, we don't miss that either. Point your domain at your app, run fly certs add, and fetch a warm beverage. By the time you're back, your site will have a Let's Encrypt certificate and that sweet green padlock.

Certificates appear like magic (it's actually Let's Encrypt, but shh)

Wildcard domains because you have grand plans

Auto-renewal so you never wake up to expired cert alerts

Modern TLS that makes security auditors smile

Learn more in our docs

You Build Epic Things, We'll Make Sure They Talk To Each Other

Deploy your app, it connects to stuff. No one's building character by manually configuring VPCs at 2am. Skip the snake wrangling and ship something cool instead.