Lightweight WASM-based alternative to ContainerCodeExecutor for sandboxed local execution

[mavdol]

Problem

ADK doesn't have many sandboxed local alternatives for code execution. The only option is ContainerCodeExecutor which relies on Docker. Beyond requiring a Docker daemon to be available, it can also add complexity in production, especially when the app or agent is already running inside a container. Nested containers (DinD) require elevated privileges, which can compromise the isolation and defeat the very purpose of sandboxing.

Proposed solution

The solution I'm proposing is based on Vpod, an open-source project I maintain. A vpod is a tiny Linux sandbox that runs inside WebAssembly for untrusted processes. It uses snapshots with preinstalled libraries to start fast and avoid setup complexity.

Here's an example of what the code execution inside a VpodCodeExecutor could look like:

from google.adk.agents import Agent
from vpod_adk import VpodCodeExecutor

agent = Agent(
    name="secure_coder",
    model="gemini-2.0-flash",
    instruction="Execute Python code in a secure sandbox.",
    code_executor=VpodCodeExecutor(snapshot="vsnap-data"),  # numpy/pandas/scipy preinstalled
)

Under the hood, it's a thin wrapper over Vpod's Python SDK:

from vpod import Sandbox

with Sandbox.create(snapshot="vsnap-data") as sandbox:
    sandbox.code.run("import pandas as pd")
    result = sandbox.code.run("print(pd.Series([1,2,3]).sum())")
    print(result.text)

Sandboxes are highly portable and work on any OS or environment. They also can be suspended and resumed on disk without any background process or daemon.

Trade-offs, up front

Vpod is based on RISC‑V emulated in WASM and doesn't benefit from hardware acceleration, so CPU‑heavy workloads might run slower than native. It's mainly aimed at safely running typical agent-generated code, not at max-throughput compute.

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I'm curious whether anyone here has run into this with Docker and ContainerCodeExecutor in production. If so, I'd love to hear how you worked around it.

Here's more information about Vpod:

• Repository: https://github.com/capsulerun/vpod
• PyPI: pip install vpod