Fork

Fork clones a running machine — memory, processes, and filesystem — into an independent child. This example writes shared state, forks, then changes each side to show they no longer affect each other.

Setup

uv pip install "nullspace-sdk==1.0.0"
export NULLSPACE_API_KEY=ns_live_...
export NULLSPACE_API_URL=https://api.your-nullspace-domain

Python

fork_example.py

from nullspace import Machine

with Machine.create(template="base", timeout=120) as parent:
    parent.files.write("/workspace/state.txt", "common\n")

    child = parent.fork()
    try:
        parent.files.write("/workspace/state.txt", "common\nparent\n")
        child.files.write("/workspace/state.txt", "common\nchild\n")

        print("parent:", parent.files.read("/workspace/state.txt").split())
        print("child: ", child.files.read("/workspace/state.txt").split())
    finally:
        child.kill()

Expected output

parent: ['common', 'parent']
child:  ['common', 'child']

The child starts as an exact copy (it sees common), then each side’s write lands only in its own filesystem. Fork children are full machines: fork them again, hibernate them, or expose ports — anything a created machine can do.

Where this is useful

Parallel exploration — set up a repo or environment once, fork per hypothesis, keep the winner.
Cheap retries — fork before a risky step; on failure, kill the child and fork again instead of rebuilding state.
Evaluation — run N candidate patches against identical warm state.

Related: Fork concept · Machine fork guide

Overview

Machine patterns

Networking and access

Agent deployments

Setup

Python

Expected output

Where this is useful

​Setup

​Python

​Expected output

​Where this is useful

Setup

Python

Expected output

Where this is useful