Unfortunately, Sprites Now Speak MCP
Sprites are disposable cloud computers. They appear instantly, always include durable filesystems, and cost practically nothing when idle. They’re the best and safest place on the Internet to run age…
The Fly Blog
News, tips, and tricks from the team at Fly
March 2026
January 2026
Litestream Writable VFS
I’m Ben Johnson, and I work on Litestream at Fly.io. Litestream is the missing backup/restore system for SQLite. It’s free, open-source software that should run anywhere, and you can read more about…
The Design & Implementation of Sprites
We’re Fly.io, and this is the place in the post where we’d normally tell you that our job is to take your containers and run them on our own hardware all around the world. But last week, we launched…
Code And Let Live
The state of the art in agent isolation is a read-only sandbox. At Fly.io, we’ve been selling that story for years, and we’re calling it: ephemeral sandboxes are obsolete. Stop killing your sandboxes…
December 2025
Litestream VFS
I’m Ben Johnson, and I work on Litestream at Fly.io. Litestream is the missing backup/restore system for SQLite. It’s free, open-source software that should run anywhere, and you can read more about…
November 2025
You Should Write An Agent
Some concepts are easy to grasp in the abstract. Boiling water: apply heat and wait. Others you really need to try. You only think you understand how a bicycle works, until you learn to ride one. The…
October 2025
Corrosion
Fly.io transmogrifies Docker containers into Fly Machines: micro-VMs running on our own hardware all over the world. The hardest part of running this platform isn’t managing the servers, and it isn’t…
Kurt Got Got
The $FLY Airdrop is live! Claim your share of the token powering Fly.io’s global network of 3M+ apps and (🤮) own a piece of the sky! We know. Our Twitter got owned. We knew within moments of it happ…
Litestream v0.5.0 is Here
I’m Ben Johnson, and I work on Litestream at Fly.io. Litestream makes it easy to build SQLite-backed full-stack applications with resilience to server failure. It’s open source, runs anywhere, and it…
August 2025
Build Better Agents With MorphLLM
I’m an audiophile, which is a nice way to describe someone who spends their children’s college fund on equipment that yields no audible improvement in sound quality. As such, I refused to use wireles…
Trust Calibration for AI Software Builders
Trust calibration is a concept from the world of human-machine interaction design, one that is super relevant to AI software builders. Trust calibration is the practice of aligning the level of trust…
Games as Model Eval: 1-Click Deploy AI Town on Fly.io
Recently, I suggested that The Future Isn’t Model Agnostic , that it’s better to pick one model that works for your project and build around it, rather than engineering for model flexibility. If you…
The Future Isn't Model Agnostic
Your users don’t care that your AI project is model agnostic. In my last project, I spent countless hours ensuring that the LLMs running my services could be swapped out as easily as possible. I coul…
June 2025
Phoenix.new – The Remote AI Runtime for Phoenix
I’m Chris McCord, the creator of Elixir’s Phoenix framework. For the past several months, I’ve been working on a skunkworks project at Fly.io, and it’s time to show it off. I wanted LLM agents to wor…
What are MCP Servers?
With Fly.io, you can get your app running globally in a matter of minutes , and with MCP servers you can integrate with Claude, VSCode, Cursor and many more AI clients . Try it out for yourself ! The…
My AI Skeptic Friends Are All Nuts
A heartfelt provocation about AI-assisted programming. Tech execs are mandating LLM adoption. That’s bad strategy. But I get where they’re coming from. Some of the smartest people I know share a bone…
May 2025
Using Kamal 2.0 in Production
Agile Web Development with Rails 8 is off to production, where they do things like editing, indexing, pagination, and printing. In researching the chapter on Deployment and Production, I became very…
parking_lot: ffffffffffffffff...
We’re Fly.io, a public cloud that runs apps in a bunch of locations all over the world. This is a post about a gnarly bug in our Anycast router, the largest Rust project in our codebase. You won’t ne…
Litestream: Revamped
Litestream is an open-source tool that makes it possible to run many kinds of full-stack applications on top of SQLite by making them reliably recoverable from object storage. This is a post about th…
Launching MCP Servers on Fly.io
This is a blog post. Part showing off. Part opinion. Plan accordingly. The Model Context Protocol is days away from turning six months old. You read that right, six months old. MCP Servers have both…
Provisioning Machines using MCPs
Today’s state of the art is K8S, Terraform, web based UIs, and CLIs. Those days are numbered. On Monday, I created my first fly volume using an MCP . For those who don’t know what MCPs are, they are…
April 2025
30 Minutes With MCP and flyctl
I wrote this post on our internal message board, and then someone asked, “why is this an internal post and not on our blog”, so now it is. well, Cursor built I built the most basic MCP server for fly…
Our Best Customers Are Now Robots
We’re Fly.io, a developer-focused public cloud. We turn Docker containers into hardware-isolated virtual machines running on our own metal around the world. We spent years coming up with a developer…
March 2025
Operationalizing Macaroons
We’re Fly.io, a security bearer token company with a public cloud problem. You can read more about what our platform does (Docker container goes in, virtual machine in Singapore comes out), but this…
February 2025
Taming A Voracious Rust Proxy
Here’s a fun bug. The basic idea of our service is that we run containers for our users, as hardware-isolated virtual machines (Fly Machines), on hardware we own around the world. What makes that int…
We Were Wrong About GPUs
We’re building a public cloud, on hardware we own. We raised money to do that, and to place some bets; one of them: GPU-enabling our customers. A progress report: GPUs aren’t going anywhere, but: GPU…
The Exit Interview: JP Phillips
JP Phillips is off to greener, or at least calmer, pastures. He joined us 4 years ago to build the next generation of our orchestration system, and has been one of the anchors of our engineering team…
Did Semgrep Just Get A Lot More Interesting?
This whole paragraph is just one long sentence. God I love just random-ass blogging again. This bit by Geoffrey Huntley is super interesting to me and, despite calling out that LLM-driven development…
A Blog, If You Can Keep It
A boldfaced lede like this was a sure sign you were reading a carefully choreographed EffortPost from our team at Fly.io. We’re going to do less of those. Or the same amount but more of a different k…
VSCode’s SSH Agent Is Bananas
We’re interested in getting integrated into the flow VSCode uses to do remote editing over SSH, because everybody is using VSCode now, and, in particular, they’re using forks of VSCode that generate…
September 2024
AI GPU Clusters, From Your Laptop, With Livebook
Livebook, FLAME, and the Nx stack: three Elixir components that are easy to describe, more powerful than they look, and intricately threaded into the Elixir ecosystem. A few weeks ago, Chris McCord (…
August 2024
Accident Forgiveness
We’re Fly.io, a new public cloud with simple, developer-friendly ergonomics. Try it out; you’ll be deployed in just minutes , and, as you’re about to read, with less financial risk. Public cloud bill…
We're Cutting L40S Prices In Half
We’re Fly.io, a new public cloud with simple, developer-friendly ergonomics. And as of today, cheaper GPUs. Try it out; you’ll be deployed in just minutes . We just lowered the prices on NVIDIA L40s…
July 2024
Making Machines Move
We’re Fly.io, a global public cloud with simple, developer-friendly ergonomics. If you’ve got a working Docker image, we’ll transmogrify it into a Fly Machine: a VM running on our hardware anywhere i…
June 2024
AWS without Access Keys
It’s dangerous to go alone. Fly.io runs full-stack apps by transmuting Docker containers into Fly Machines: ultra-lightweight hardware-backed VMs. You can run all your dependencies on Fly.io, but som…
May 2024
Picture This: Open Source AI for Image Description
I’m Nolan, and I work on Fly Machines here at Fly.io. We’re building a new public cloud—one where you can spin up CPU and GPU workloads, around the world, in a jiffy. Try us out ; you can be up and r…
March 2024
JIT WireGuard
We’re Fly.io and we transmute containers into VMs, running them on our hardware around the world with the power of Firecracker alchemy. We do a lot of stuff with WireGuard, which has become a part of…
Fly Kubernetes does more now
Eons ago, we announced we were working on Fly Kubernetes . It drummed up enough excitement to prove we were heading in the right direction. So, we got hard to work to get from barebones “early access…
February 2024
Globally Distributed Object Storage with Tigris
We’re Fly.io and we transmute containers into VMs, running them on our hardware around the world with the power of Firecracker alchemy. That’s pretty cool, but we want to talk about something someone…
GPUs on Fly.io are available to everyone!
Fly.io makes it easy to spin up compute around the world, now including powerful GPUs. Unlock the power of large language models, text transcription, and image generation with our datacenter-grade mu…