Ephemeral sandboxes for AI agents
Agents need somewhere to run code, but per-hour sandboxes add up. Alrith turns any Linux server into an open-source, ephemeral sandbox platform.
Agents are starting to write and run code constantly: to test an idea, install a dependency, break something, and throw the result away. Managed sandboxes answer that need, but they are priced by the hour, and the meter runs whether the agent is working or not. For a tool you want agents to use all day, that gets expensive fast.
We want a free and open-source alternative. That is why we are building Alrith.
What Alrith is
Alrith is an open-source, self-hosted sandbox runtime for AI agents. It turns any Linux server into an ephemeral compute platform where agents safely spin up isolated microVMs, run code, experiment, and destroy them when finished.
The servers you already run are often idle. Alrith makes them reusable: agents get a clean sandbox whenever they need one, and the capacity comes from hardware you already pay for.
Sandboxes that live for minutes, not months
Sandboxes are ephemeral by design. Keep one until it goes idle, or give it a fixed lifetime such as 50 minutes, and let it disappear on its own. Sizes start at 512 MB RAM and 2 vCPU.
Under the hood, the runtime is built in Rust on Firecracker microVMs. Sandboxes boot in under 1 second, so an agent can spin one up in the middle of a task without pausing to think about it.
Built for agents, driven by agents
Sandboxes can be created through an API endpoint or from the CLI, and the Sandbox MCP server lets AI agents spin up their own sandboxes to try new things without asking a human first.
Connect multiple VPS or servers and Alrith dynamically decides where each sandbox is created, so placement follows your fleet instead of a fixed host.
An alternative to paid sandboxes
Per-hour sandbox platforms are convenient, but they are closed and metered. A paid offering like Vercel Sandbox charges for time you often do not need.
Alrith takes the opposite approach: free, open source, and self-hosted. Your servers, your sandboxes, your data.
If you want agents to experiment freely, without a meter running, this is for you.