Fly.io Machines vs Google Agent Runtime

Fly.io Machines boot the image you build as a Firecracker microVM with root, made for hosting apps in 17 regions. Google Agent Runtime hosts agent code on Google Cloud and gives it sandboxes that run as an unprivileged user in a locked container.

The companies and products

Fly.io Machines

Fly.io is an app hosting platform, and Machines are the microVMs underneath it that you can also start and stop through a REST API.

A Fly Machine boots your Docker image as a Firecracker microVM on Fly's own servers, in one of 17 regions. You pick a shared or performance CPU preset, attach at most one Volume for data that must last, and Fly Proxy can stop, suspend and wake Machines as traffic comes and goes. It is built for teams that host web apps and services worldwide; it is not a sandbox product, so this page compares the parts that overlap with agent work.

Google Agent Runtime

Google Agent Runtime is the agent hosting part of Gemini Enterprise Agent Platform on Google Cloud, renamed from Vertex AI Agent Engine in April 2026.

It is a hyperscaler service, not a sandbox company. Agent Runtime deploys agents you build with ADK, LangGraph, LangChain, AG2 or LlamaIndex and bills them only while they work on a turn. Next to it, Agent Sandbox gives those agents a place to run code: a Code Execution sandbox, a shell or custom container sandbox, and a Computer Use browser. All of them run as secure containers inside your Google Cloud project.

Which use cases each one fits

For each use case, Battleships prices every sandbox provider on the same workload and sorts them from the cheapest monthly bill up. “92nd cheapest of 367” means 91 of the other 366 providers run that workload, with every feature it needs, for less. “With limits” means the provider runs it but misses something, so it is listed after every full match. Open a use case for its whole ranking and what each provider misses.

Use case and its workloadFly.io Machines: price rankGoogle Agent Runtime: price rankbochka: price rank
Software factory
100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month
Fly gives root and lets you install Docker yourself, while Google's sandboxes have neither, so Fly sits far above Google here; bochka fits fully with Docker and /dev/kvm ready.
92nd of 367, with limits
$836 a month
295th of 367, with limits
$5,801 a month
3rd cheapest of 367
$634 a month
Always-on AI employees
50 machines 24/7 · 2 vCPU / 4 GB
Google fits fully here, since Runtime hosts a long-lived agent and bills only its working turns; on Fly the root disk resets on restart, so lasting memory must live on a Volume.
125th of 366, with limits
$816 a month
28th cheapest of 366
$7,519 a month
5th cheapest of 366
$657 a month
Code interpreter bursts
100 at once · 1 vCPU / 2 GB · 200,000 sessions of 1 min a month
Both are a compromise: Fly suits short bursts with per-second billing and cheap shared CPU, and Google's Code Execution sandbox is a ready Python interpreter with no network.
75th of 345, with limits
$94 a month
254th of 345, with limits
$275 a month
186th of 345, with limits
$2,000 a month
Sandboxes for your users
300 at once · 2 vCPU / 4 GB · 30,000 sessions of 23 min a month
Fly can give each user a public URL through Fly Proxy, while Google documents no public URL for a sandbox; bochka serves HTTPS on up to 50 ports per sandbox.
69th of 361, with limits
$600 a month
280th of 361, with limits
$1,916 a month
Cheapest of 361
$209 a month
RL rollouts
1,000 at once · 2 vCPU / 4 GB · 1,000,000 sessions of 3 min a month
48th of 360, with limits
$2,838 a month
128th of 360, with limits
$8,240 a month
34th of 360, with limits
$2,000 a month
Agent evals
250 at once · 4 vCPU / 8 GB · 15,000 sessions of 20 min a month
117th of 364, with limits
$457 a month
79th cheapest of 364
$2,060 a month
10th cheapest of 364
$200 a month
CI runners
40 at once · 8 vCPU / 16 GB · 6,000 sessions of 12 min a month
CI jobs that build containers need Docker, which Google's sandboxes do not have and Fly makes you install, and busy builds drain a shared Fly vCPU's burst balance.
152nd of 377, with limits
$288 a month
98th cheapest of 377
$989 a month
4th cheapest of 377
$86 a month
24/7 dev boxes
1 machine 24/7 · 4 vCPU / 8 GB
Fly lets you SSH into a Machine, while Google has no SSH and runs each command in a new shell; bochka gives you SSH and a desktop.
118th of 368, with limits
$53 a month
311th of 368, with limits
$241 a month
18th cheapest of 368
$26 a month
Computer-use agents
50 at once · 4 vCPU / 8 GB · 20,000 sessions of 15 min a month
Google gives agents a browser with a VNC view and a click and type API, Fly has nothing built in, and bochka streams a full 60fps desktop with Chromium.
95th of 369, with limits
$173 a month
283rd of 369, with limits
$1,648 a month
6th cheapest of 369
$200 a month
Browser-use agents
50 at once · 2 vCPU / 4 GB · 30,000 sessions of 10 min a month
160th of 367, with limits
$90 a month
102nd of 367, with limits
$824 a month
7th cheapest of 367
$200 a month
Scraping & bots (startup scale)
50 at once · 1 vCPU / 2 GB · 100,000 sessions of 3 min a month
161st of 346, with limits
$67 a month
53rd cheapest of 346
$515 a month
6th cheapest of 346
$90 a month
Mass scraping & bots (undetectable)
1,000 at once · 1 vCPU / 2 GB · 3,000,000 sessions of 2 min a month
Fly does best of the three here: it spreads scrapers across 17 regions and bills only the seconds they run.
44th of 338, with limits
$1,232 a month
210th of 338, with limits
$8,240 a month
71st of 338, with limits
$1,800 a month
Parallel red teaming
200 at once · 2 vCPU / 4 GB · 5,000 sessions of 30 min a month
118th of 360, with limits
$63 a month
260th of 360, with limits
$412 a month
2nd cheapest of 360
$200 a month
GPU eval jobs
10 at once · 8 vCPU / 32 GB · 500 sessions of 30 min a month
Can't run itCan't run itCan't run it
macOS agents
5 at once · 4 vCPU / 8 GB · 1,000 sessions of 20 min a month
Can't run itCan't run itCan't run it

Key features

FeatureFly.io MachinesGoogle Agent Runtimebochka
Kind of productApp hosting platform; you boot your own image as a microVM through a REST APIManaged agent hosting plus code, shell and browser sandboxes on Google CloudAgent sandbox: a full VM per agent, ready to use
IsolationFirecracker microVM with its own kernel, on Fly's own serversSecure container sandboxing inside your Google Cloud projectFull VM with its own kernel on dedicated AMD Ryzen 9 9950X (Zen 5) hosts
Root, Docker and nested virtualizationRoot, and Docker you install yourself; Fly's own init, no systemd; no /dev/kvmRuns as appuser with no sudo; images must not need root; no Docker or /dev/kvm documentedRoot, systemd, Docker and /dev/kvm on every machine
Files after a stopRoot file system is ephemeral; lasting data goes on one Volume, billed for its full size around the clockPause keeps the file system at a rate Google does not publish; the sandbox is deleted when its TTL endsThe whole disk is kept, with snapshots every minute and on stop; a stopped sandbox costs nothing
Memory snapshots and branchingSuspend keeps memory for Machines up to 2GB; a clone copies the config and gets an empty VolumeSnapshots keep memory and files; start many sandboxes from one snapshotFork a running sandbox, disk included; resume reboots from disk (no memory snapshots)
How long a machine livesNo documented maximum runtimeTTL of up to 7 days for a custom container and 14 days for Code ExecutionNo session cap on paid plans
Desktop and computer useNone built in; you add a desktop and browser to your own imageA browser with a VNC live view, a click, type and screenshot API, and CDP for Playwright60fps desktop and Chromium, computer use and browser control, embeddable stream
Coding agentsNone built in; you install and run agents yourselfManaged Agents API (Preview) runs Google's Antigravity harnessClaude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API
Hosting your agent codeYou run your agent as your own app on a MachineAgent Runtime deploys ADK, LangGraph, LangChain, AG2 and LlamaIndex agents; idle time between turns is not billedYou run your own agent loop inside a sandbox
Keeping keys out of the sandboxSecrets arrive as environment variables; Fly's open-source tokenizer proxy can be deployed yourselfYou provision and scope the credentials the agent usesAI credentials proxy for model providers and any HTTPS API; switch a credential to another account when credits run out
Reaching the machineSSH; public HTTPS and TCP through Fly Proxy, Anycast IPs, custom domains, private networkThrough Google's API or a private endpoint in your own VPC; no SSH or public URL documentedSSH; HTTPS URLs for up to 50 ports, token-protected; raw TCP; dedicated IPv6 or IPv4
Wake and idleFly Proxy stops or suspends idle Machines and wakes them when a request arrivesRuntime bills only while an agent works on a turn; sandboxes bill while they existYou start and stop machines through the API; a stopped one costs nothing
Outbound rulesNetwork policies allow chosen ports and protocols and deny the restOff unless the template turns it on; route through your VPC with Cloud NAT, a static IP, Cloud NGFW or Secure Web ProxyOpen internet on every plan; no provider-side allowlist
Regions17 regions on six continents23 locations in the US, Europe, Asia, Canada, Australia and BrazilEU only: Germany, Finland, France
Every feature Battleships tracks (43)
FeatureFly.io MachinesGoogle Agent Runtimebochka
Full VM (own kernel)YesNoYes
Docker insideYesNoYes
Nested virtualizationNoNoYes
RootYesNoYes
SystemdNoNot publishedYes
Desktop GUINoNoYes
BrowserNoYesYes
Computer-use APINoYesYes
SSHYesNoYes
Persistent diskYesYesYes
Pause/resumeYesYesYes
Automatic snapshotsYesYesYes
Fork/cloneYesYesYes
Live fork (no pause)YesYesYes
Memory forkNoYesNo
Custom image (Docker or snapshot)YesYesYes
≥24 h sessionsYesYesYes
Idle auto-stopYesNoNo
Wake on requestYesNoNo
HTTPS preview URLsYesNoYes
Raw TCP inboundYesNot publishedYes
Public IPv4YesNoNo
Egress allowlistYesYesNo
Secret proxyNoNoYes
Secret proxy for any APINoNoYes
Preinstalled agentsNoYesYes
Agent harness APINoYesYes
MCP serverYesNoNo
GPUNoNoNo
WindowsNoNoNo
Arm64NoYesNo
Self-hostingNoNoNo
BYOCNoNoNo
Open sourceYesNoNo
Scoped API keysNot publishedNot publishedYes
Spend limitsNoNot publishedYes
Usage per sandbox (API)NoYesYes
Audit logsNot publishedNot publishedNo
SSONoYesNo
SOC 2YesYesNo
HIPAAYesYesNo
EU data residencyYesYesYes
Zero data retentionNot publishedNot publishedYes

Performance

Fly.io MachinesNot measured
Google Agent RuntimeNot measured
bochka26.69 runs/s

There is no comparable measurement for Fly.io Machines or Google Agent Runtime: neither was part of the public StarSling run where bochka did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB. On Fly, results would depend on the CPU class, since shared vCPUs guarantee only 6.25% of a core with a burst balance while performance vCPUs get the full core.

Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Fly.io Machines and Google Agent Runtime have no published run in this suite yet, so there is no like-for-like number to compare.

Pricing in five scenarios

Each bill is priced from the providers' public price lists by the open Battleships engine, with the cheapest plan that runs the scenario.

ScenarioFly.io Machines, a monthGoogle Agent Runtime, a monthbochka, a month
One coding agent, workdays
4 vCPU / 8 GB, 50 GB disk, 8 hours a day, 22 days a month, files kept between days
$15 · Pay As You Go · with limits$73 · Pay as you go$20 · $20/mo
One agent that never stops
4 vCPU / 8 GB, 50 GB disk, running 24/7 all month
$36 · Pay As You Go · with limits$301 · Pay as you go$26 · $20/mo
50 agents in parallel
50 machines of 4 vCPU / 8 GB at once, 8-hour sessions, 1,100 sessions a month, Docker inside
$487 · Pay As You Go · with limits$3,626 · Pay as you go · with limits$317 · $20/mo × 3 seats
Sandboxes for your users
2 vCPU / 4 GB, 30,000 sessions of 10 minutes a month, up to 300 at once
$110 · Pay As You Go · with limits$1,030 · Pay as you go$200 · $100/mo × 2 seats
1,000 short jobs at once
2 vCPU / 4 GB, 1,000 at once, 3 minutes each, 200,000 jobs a month
$232 · Pay As You Go · with limits$2,060 · Pay as you go$2,000 · $2000/mo · with limits

Fly.io Machines: Fly bills each Machine per second while it runs, by CPU preset and memory, with no plan fee, and Volumes are billed for their full size all month. The figures here use Fly's lowest rate: shared vCPUs bought in 1-year reservation blocks for 40% off.

Google Agent Runtime: Google bills $0.085 per vCPU-hour and $0.009 per GiB-hour allocated, with the first 50 vCPU-hours and 100 GiB-hours free each month. Runtime skips idle time between turns, but sandboxes bill while they exist, and disk and egress rates are not published.

Google Agent Runtime: You pick a monthly plan from $20, and all of it becomes usage credit spent per second on running sandboxes. A stopped sandbox costs nothing and keeps its disk.

Limits in those scenarios

Fly is a compromise in all five scenarios: its lowest figures need a 1-year reservation and use shared vCPUs that guarantee only 6.25% of each core, so long builds get throttled, and its API starts about one Machine per second per app. Google cannot run the 50-agent fleet because its sandboxes have no Docker, a sandbox is deleted when its TTL ends, and every Google row leaves disk and egress unpriced. On bochka the 1,000-job burst gets queued, since starts are capped at 90 a minute and 2,400 a day on the $2,000 plan.

ScenarioFly.io MachinesGoogle Agent Runtimebochka
One coding agent, workdays
  • different kind of product: app platform
  • 1-year commitment
  • burstable CPU: 6.25% of each vCPU guaranteed, throttled above that
  • disk beyond 0 GiB: price unknown
  • egress price not published
None that bite
One agent that never stops
  • different kind of product: app platform
  • 1-year commitment
  • burstable CPU: 6.25% of each vCPU guaranteed, throttled above that
  • disk beyond 0 GiB: price unknown
  • egress price not published
None that bite
50 agents in parallel
  • different kind of product: app platform
  • 1-year commitment
  • burstable CPU: 6.25% of each vCPU guaranteed, throttled above that
  • missing Docker inside
  • disk beyond 0 GiB: price unknown
  • egress price not published
None that bite
Sandboxes for your users
  • different kind of product: app platform
  • 1-year commitment
  • burstable CPU: 6.25% of each vCPU guaranteed, throttled above that
  • disk beyond 0 GiB: price unknown
  • egress price not published
None that bite
1,000 short jobs at once
  • different kind of product: app platform
  • 1-year commitment
  • burstable CPU: 6.25% of each vCPU guaranteed, throttled above that
  • disk beyond 0 GiB: price unknown
  • egress price not published
  • max 2,400 starts/day (needs ~6,667)
  • max 600 starts/hour (needs ~1,000)
  • bursts above 90 starts/min are queued (a burst of 333 takes ~4 min to start)

Which one should you use?

Use Fly.io Machines when

you want to build your own sandbox image with root, host what it makes on public URLs, and run near users in 17 regions.

  • A root microVM with no time limit. Useful if you want your own image with root and Docker inside: Fly boots it as a microVM and documents no maximum runtime.
  • Public apps in 17 regions. Useful for showing what agents build: Fly Proxy gives HTTPS, TCP, custom domains and Anycast IPs in 17 regions.
  • Wake on request. Useful for services that sleep between requests: Fly Proxy wakes a Machine on traffic, and small Machines resume with memory kept.

Use Google Agent Runtime when

you build agents with ADK or LangGraph on Google Cloud and want them hosted inside your own project and network, with short code runs in a locked sandbox.

  • A managed home for your agent code. Useful if you build agents with ADK or LangGraph: Agent Runtime hosts them and skips billing for idle time between turns.
  • Inside your Google Cloud network. Useful if agents must stay in a Google Cloud perimeter, with egress off by default and routed through your own firewall.
  • Memory snapshots to branch from. Useful for trying many paths: a Google snapshot keeps files and memory, and many sandboxes can start from one.

Where bochka fits

Fly gives you a building block to turn into a sandbox, and Google gives you a locked container tied to its own agent stack. If what you are really running is coding agents that install, build and test for hours, bochka gives each one a full VM with the tools, the desktop and the agents already inside.

Root, Docker and /dev/kvm ready

Google's sandboxes run as appuser with no sudo or Docker. Fly gives root, but you install Docker into your image, run without systemd and get no /dev/kvm, so emulators and nested VMs are out on both.

A disk that survives every stop

A Fly Machine's root file system is ephemeral, so lasting files need a Volume billed for its full size all month. A Google sandbox is deleted when its TTL ends, 7 days at most. bochka keeps the whole disk, saved every minute.

Coding agents and keys built in

Fly ships no agents and passes secrets as environment variables, and Google runs only its own Antigravity harness in Preview. bochka preinstalls Claude Code and Codex, drives them from outside, and keeps real keys out through its credentials proxy.

Use bochka when your agents need a real computer for hours: root, Docker, /dev/kvm, a desktop and public URLs on a full VM that keeps its disk, with coding agents and a keys proxy built in. Compare it one to one: bochka vs Fly.io Machines and bochka vs Google Agent Runtime.

Questions people ask

Is Fly.io Machines cheaper than Google Agent Runtime?

In all five scenarios we priced, yes, using Fly's shared vCPUs on a 1-year reservation. One agent running all month is $36 on Fly and $301 on Google, 50 agents in parallel are $487 versus $3,626, and 1,000 short jobs at once are $232 versus $2,060. bochka comes to $26, $317 and $2,000 for the same three, and Fly's figures assume work that stays within a shared vCPU's 6.25% baseline.

Which is faster, Fly.io Machines or Google Agent Runtime?

Neither has a comparable public measurement. bochka did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB in StarSling's run, and Fly's speed depends on whether you pick shared or performance vCPUs.

Can Fly.io Machines or Google Agent Runtime run Docker?

On Fly you can install and run Docker inside a Machine yourself, since it is a microVM with root, but there is no /dev/kvm for nested VMs. Google's sandboxes run as the unprivileged user appuser with no sudo, so Docker is not available. bochka has Docker, systemd and /dev/kvm ready on every machine.

Do they keep my files when a machine stops?

On Fly only what is on the one Volume a Machine can mount, since the root file system is ephemeral. A paused Google sandbox keeps its files, but the sandbox is deleted when its TTL ends, 7 days at most for a custom container. On bochka the whole disk is kept, with snapshots every minute and on stop.

Is Google Agent Runtime the same as Vertex AI Agent Engine?

Yes. Google renamed Vertex AI Agent Engine to Agent Runtime in April 2026, as part of Gemini Enterprise Agent Platform. Its code, shell and browser sandboxes are a separate part called Agent Sandbox.

Where does my data run?

Fly runs Machines in 17 regions on six continents, and Google runs Agent Runtime in 23 locations across the US, Europe, Asia, Canada, Australia and Brazil. bochka runs only in the EU (Germany, Finland and France), with EU data residency.

Try bochka

Install the CLI, then run bochka new.

Product preview

More comparisons

Bochka product preview · Pricing, benchmarks and commands are illustrative. Sandbox provisioning is not connected.