On Runtime, the IDE backend runs in its own microVM. Runtime's authenticated API reaches it, so no SSH port is open to the internet. You size the machine to the project. You pay for the CPU it uses at $0.025 per active vCPU-hour, plus $0.0075 per reserved GiB-hour of memory. The machine pauses when you stop working (pricing). There is no plan fee. Prepaid credit starts at $10, and every account gets 100 free hours of a 1 GB machine in its first 30 days.
Connect
Once, on your machine:
Terminalnpm install --global withruntimeruntime sandboxes ssh config --install # every sandbox becomes <id>.runtime to OpenSSHThen in JetBrains Gateway:
- Under SSH, choose New Connection.
- Host:
<id>.runtimeor<name>.runtime. User:runtime. - Authentication: Parse config file ~/.ssh/config, so Gateway uses the
entry the CLI installed and its
ProxyCommand. - Pick the IDE and the project directory, such as
/workspace/app.
Gateway downloads the IDE backend into the sandbox. It opens the project in
JetBrains Client on your machine. That client is the thin window you type in
(JetBrains docs,
read 26 October 2026). By default, the backend is installed in
~/.cache/JetBrains/RemoteDev/dist, which is under /workspace in a sandbox.
Size the sandbox for an IDE
An IDE backend indexes the whole project. JetBrains recommends more CPUs and memory for larger projects (prerequisites, read 26 October 2026). Request these resources when you create the sandbox:
TypeScriptimport { Sandbox } from "withruntime";const ide = await Sandbox.getOrCreate("ide", { vcpu: 4, memoryMiB: 8192, diskMiB: 20_480, idlePauseSeconds: 1800,});console.log(`${ide.info.name}.runtime`);Pythonfrom withruntime import Sandboxide = Sandbox.get_or_create("ide", vcpu=4, memory_mib=8192, disk_mib=20_480, idle_pause_seconds=1800)print(f"{ide.info['name']}.runtime")Terminalruntime sandboxes create --name ide --get-or-create --vcpu 4 --memory 8192 --disk 20480 --idle-pause 1800| Resource | What it costs | Note |
|---|---|---|
| CPU | $0.025 per active vCPU-hour, as used | Idle cores between builds cost only the 50-millicore floor |
| Memory | $0.0075 per reserved GiB-hour | 8 GiB costs $0.06 an hour while running |
| Disk | Chosen with --disk |
The IDE backend and its caches are stored on it |
| Paused | $0.08 per decimal GB per 30-day month of storage | No compute charge. Files, memory and processes are kept |
Indexing is the busy part. Once it is done, a backend that waits for you uses little CPU. CPU is billed on what is measured.
Keep the project warm
A named sandbox with an idle pause is the same workspace each morning, with its
index still on disk. To build that workspace faster the first time, start from
a custom image that already has your JDK, Python or Node
toolchain. The command sudo apt-get update && sudo apt-get install -y openjdk-21-jdk
also works, once per sandbox.
Mistakes and how Runtime handles them
- Choosing a password or a key file in Gateway. The installed entry's
ProxyCommandis what reaches the sandbox. So choose the option that parses~/.ssh/config. - The IDE disconnects at a time limit. An open connection keeps a sandbox
running. There is no time limit by default. A sandbox created with
--timeoutstill ends the session at that limit. Leave the timeout out. Or, for all-day work that must never pause, make a paid sandbox--persistent. - Sessions past a day. Each SSH connection lasts at most 24 hours. Open it again to continue.
- Several IDEs and forwards at the same time. An organization can have at most 16 SSH logins and port forwards open at the same time. On top of that, each sandbox it holds that is not stopped adds two more, up to 292.
- Running out of disk. The default 4 GiB disk had about 2.5 GiB free on 24 September 2026. That is too little for an IDE backend and a large project. Request more at create.
Gateway, VS Code or a shell?
Gateway suits Java, Kotlin and other projects where you use a JetBrains IDE for
its indexing and refactoring. VS Code Remote-SSH
keeps the editor on your machine and runs its server in the sandbox. For quick
fixes, SSH in from a terminal. All of them use the
same <id>.runtime host.
Related
Sources
- JetBrains, "Connect and work with JetBrains Gateway", https://www.jetbrains.com/help/idea/remote-development-a.html, read 26 October 2026.
- JetBrains, "Prerequisites", https://www.jetbrains.com/help/idea/prerequisites.html, read 26 October 2026.
Facts on this page were checked on 26 October 2026.