> ## 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

> Fly.io reference index: architecture, regions, Machine migration, flyctl, fly.toml, Fly Proxy, autostop, health checks, builders, load balancing.

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

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

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

***

## Reference docs

* **[flyctl](https://docs.fly.io/flyctl):** The flyctl CLI reference documentation.

* **[App Configuration (fly.toml)](https://docs.fly.io/reference/configuration.md):** 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](https://docs.fly.io/reference/fly-launch.md):** A deeper dive into how Fly Launch creates and configures new apps.

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

* **[Fly Proxy autostop/autostart](https://docs.fly.io/reference/fly-proxy-autostop-autostart.md):** 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](https://docs.fly.io/reference/content-encoding.md):** Learn how our proxy handles HTTP response compression, so you get better performance out of the box.

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

* **[Health Checks](https://docs.fly.io/reference/health-checks.md):** 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](https://docs.fly.io/reference/autoscaling.md):** Adjust the number of running or created Fly Machines dynamically.

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

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

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

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