zeroboot

Sub-millisecond VM sandboxes for AI agents via copy-on-write forking

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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

Author

Zeroboot was created in March 2026 and is maintained by Adam Miribyan (@adammiribyan). Project site: zeroboot.dev.

If you use zeroboot in research, please cite it; see CITATION.cff or use the "Cite this repository" button.

Cited by

• DeltaBox: Scaling Stateful AI Agents with Millisecond-Level Sandbox Checkpoint/Rollback, arXiv:2605.22781 (May 2026).
• Memory Compression for High-Fanout Agent Sandboxes (AgentZip), arXiv:2609.11294 (September 2026).

If your paper or project uses zeroboot, open an issue or pull request to add it here.

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