Zeroboot

<p align="center"> <picture> <source media="(prefers-color-scheme: dark)" srcset="assets/logo-dark.svg"> <source media="(prefers-color-scheme: light)" srcset="assets/logo-light.svg"> <img alt="Zeroboot" src="assets/logo-light.svg" width="500"> </picture> </p> <p align="center"> <strong>Sub-millisecond VM sandboxes for AI agents via copy-on-write forking</strong> </p> <p align="center"> <a href="LICENSE"><img src="https://img.shields.io/badge/license-Apache--2.0-blue" alt="License"></a> <a href="https://www.rust-lang.org"><img src="https://img.shields.io/badge/rust-2021_edition-orange" alt="Rust"></a> <a href="https://api.zeroboot.dev/v1/health"><img src="https://img.shields.io/badge/api-live-brightgreen" alt="API Status"></a> </p>

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Try it

curl -X POST https://api.zeroboot.dev/v1/exec \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer zb_demo_hn2026' \
  -d '{"code":"import numpy as np; print(np.random.rand(3))"}'

Benchmarks

| Metric | Zeroboot | E2B | microsandbox | Daytona | |---|---|---|---|---| | Spawn latency p50 | 0.79ms | ~150ms | ~200ms | ~27ms | | Spawn latency p99 | 1.74ms | ~300ms | ~400ms | ~90ms | | Memory per sandbox | ~265KB | ~128MB | ~50MB | ~50MB | | Fork + exec (Python) | ~8ms | - | - | - | | 1000 concurrent forks | 815ms | - | - | - |

Each sandbox is a real KVM virtual machine with hardware-enforced memory isolation.

How it works

  Firecracker snapshot ──► mmap(MAP_PRIVATE) ──► KVM VM + restored CPU state
                              (copy-on-write)         (~0.8ms)

1. Template (one-time): Firecracker boots a VM, pre-loads your runtime, and snapshots memory + CPU state
2. Fork (~0.8ms): Creates a new KVM VM, maps snapshot memory as CoW, restores all CPU state
3. Isolation: Each fork is a separate KVM VM with hardware-enforced memory isolation

SDKs

Python — sdk/python

from zeroboot import Sandbox
sb = Sandbox("zb_live_your_key")
result = sb.run("print(1 + 1)")

TypeScript — sdk/node

import { Sandbox } from "@zeroboot/sdk";
const result = await new Sandbox("zb_live_your_key").run("console.log(1+1)");

Docs

• API Reference
• Deployment Guide
• Architecture

Status

Working prototype. The fork primitive, benchmarks, and API are real, but not production-hardened yet. Open an issue if you're interested.

Self-host or managed

Zeroboot is open source. Self-host it on any Linux box with KVM, or use the managed API:

curl -X POST https://api.zeroboot.dev/v1/exec \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer zb_demo_hn2026' \
  -d '{"code":"import numpy as np; print(np.random.rand(3))"}'

Building the managed service for teams that don't want to run their own infra. Sign up for early access: https://tally.so/r/aQGkpb

Known limitations

• Forks share CSPRNG state from the snapshot. Kernel entropy is reseeded via RNDADDENTROPY but userspace PRNGs (numpy, OpenSSL) need explicit reseeding per fork. See Firecracker's guidance.
• Single vCPU per fork. Multi-vCPU is architecturally possible but not implemented.
• No networking inside forks. Sandboxes communicate via serial I/O only.
• Template updates require a full re-snapshot (~15s). No incremental patching.

License

Apache-2.0