> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fly.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Fly.io reference

Quick references for often-used resources like flyctl and `fly.toml`. Or dig a little deeper into Fly.io capabilities and how they work.

## About Fly.io

* **[Architecture](/reference/architecture):** A brief overview of how Firecracker VMs, Anycast networking, Fly Proxy, and the backhaul network come together to create Fly.io's infrastructure.

* **[Regions](/reference/regions):** The regions around the world where we run servers so your apps can run close to your users.

* **[Machine migration](/reference/machine-migration):** How Fly.io automatically migrates your app's Machines from problematic hosts to healthy hosts.

***

## Reference docs

* **[flyctl](/flyctl):** The flyctl CLI reference documentation.

* **[App Configuration (fly.toml)](/reference/configuration):** The settings for configuring your app in the `fly.toml` configuration file. The app configuration includes how the app is built, its volume mounts, network services, and more.

* **[Fly Launch](/reference/fly-launch):** A deeper dive into how Fly Launch creates and configures new apps.

* **[Fly Proxy](/reference/fly-proxy):** Learn about how Fly Proxy routes requests, handles connections, and does load balancing.

* **[Fly Proxy autostop/autostart](/reference/fly-proxy-autostop-autostart):** Learn how Fly Proxy determines excess capacity for an app to shut down or suspend Machines when they're not needed and start them back up when there's traffic.

* **[Fly Proxy Content Encoding](/reference/content-encoding):** Learn how our proxy handles HTTP response compression, so you get better performance out of the box.

* **[Machine Suspend/Resume](/reference/suspend-resume):** How to pause a Fly Machine in place and resume it in milliseconds.

* **[Health Checks](/reference/health-checks):** Learn how Fly monitors your apps health through HTTP, TCP, and custom checks to verify availability and trigger automatic restarts when needed.

***

## Working with Fly.io

* **[Autoscaling](/reference/autoscaling):** Adjust the number of running or created Fly Machines dynamically.

* **[Builders](/reference/builders):** The different ways you can assemble applications into deployable images for Fly.io.

* **[Load Balancing](/reference/load-balancing):** How Fly Proxy distributes traffic to your application instances based on load, closeness, and concurrency settings.

* **[Migrating from AWS to Fly.io overview](/reference/aws-to-fly-guide):** A guide with considerations for moving from AWS to Fly.io.

* **[Multiple processes inside a Fly.io app](/app-guides/multiple-processes):** The different ways to run multiple processes inside a Fly App.