forkd 0.3.1

Open-source fork-on-write microVM sandbox primitive (E2B-compatible surface)

forkd — Python SDK

E2B-compatible sandbox API backed by forkd.

from forkd import Sandbox

with Sandbox() as sandbox:
    result = sandbox.commands.run("python3 -c 'import numpy; print(numpy.zeros(3))'")
    print(result.stdout)        # [0. 0. 0.]
    print(result.exit_code)     # 0

Or with explicit lifecycle:

sandbox = Sandbox()
result = sandbox.commands.run("echo hello")
sandbox.kill()

Bonus: warmed-state eval

If your snapshot parent imported numpy, you can skip subprocess overhead and use the warmed PID-1 interpreter directly:

with Sandbox() as sandbox:
    out = sandbox.eval("numpy.zeros(5).tolist()")   # ~8 ms
    # vs commands.run("python3 -c '...'") which is ~108 ms (fresh subprocess)

Requirements

The forkd Rust CLI must be installed and on PATH, plus a parent snapshot must already exist (forkd snapshot --tag pyagent ...). See the main README for the full setup.

Status

Pre-alpha. Currently supports:

• Sandbox() / Sandbox.create() — spawn one sandbox
• sandbox.commands.run(cmd) — run command, get stdout/stderr/exit_code
• sandbox.eval(expr) — eval Python in warmed PID 1
• sandbox.kill() — terminate

Not yet (blocked on issues #1 + #4):

• Multiple concurrent Sandbox() instances (all share parent's MAC/IP)
• sandbox.files.read/write — filesystem operations
• Streaming output