harbor-box

A Harbor environment adapter backed by the Ascii Box public API.

BoxEnvironment runs Harbor agent trials and evals inside an Ascii Box instead of a local Docker container, E2B, or Modal. It implements Harbor's BaseEnvironment surface — lifecycle, command execution, environment variables, and file/dir upload + download — on top of Box's public HTTP API.

Some Harbor features aren't available on Box today: network policies, Docker image builds / Compose, and GPUs / TPUs / Windows.

Layout

Install

pip install harbor-box                 # imports as: harbor_box_environment

Or from a clone of this repo:

pip install -r requirements.txt        # harbor>=0.14.0, httpx, tenacity

Configure

cp .env.example .env
# fill in BOX_API_KEY

BOX_API_KEY is required — get one at https://box.ascii.dev. Your .env is gitignored; never commit secrets.

Use it with Harbor

export BOX_API_KEY=...
harbor task run path/to/task.yaml \
  --environment-import-path harbor_box_environment:BoxEnvironment

Preparing the environment

Box runs a ready Ubuntu image — it doesn't build Docker images. The adapter prepares each box from your Harbor environment directory instead:

• Files in the environment directory are uploaded into the box's working directory at start, so fixtures, configs, and scripts are in place before the agent runs.
• The Dockerfile is read only for its WORKDIR; build steps (RUN / COPY / …) are not executed. Install dependencies from a setup command (await env.exec(...)) or your agent, not the image.
• Environment variables come from the Harbor environment config and are forwarded into the box; per-command env is passed through exec.

task_env_config = EnvironmentConfig(
    workdir="/workspace",
    env={"DATABASE_URL": "postgres://..."},
)

Have a Dockerfile? Reproduce its RUN / COPY / WORKDIR steps on Box as a runtime setup (outbound network works, so apt/pip/npm installs run). A complete, runnable example is in examples/dockerfile_to_box.py.

Cleanup & billing

Harbor stops the box as soon as a trial (one eval run) finishes — including when it errors — so a box only costs you while a trial is actually running. By default stop() removes the box (delete=True, matching Harbor); pass delete=False to keep a resumable snapshot instead. Either way compute billing stops. The ttl_seconds you set is just a safety backstop for an abandoned box.

Isolation

Boxes are no-env by default: a trial gets none of your Box account's secrets, credentials, or cloned repos and can't act on your account or other boxes. Pass no_env=False to use your account's environment instead, configured in the Box dashboard. See Secrets & Setup.

Verify the adapter

A self-contained end-to-end self-test exercises start → persistent/per-command env vars → binary upload/download → nested directory upload/download → stop:

export BOX_API_KEY=...
python sdks/harbor_box_environment.py
# -> Box Harbor adapter e2e self-test PASSED

CI runs this self-test on every push.

Evals

A from-scratch Claude Agent SDK coding agent solving tasks inside a Box, scored by inspecting the result. See sdks/harbor-box-evals/README.md.

Releasing

Maintainers publish harbor-box to PyPI from a local checkout — see docs/release.md. CI never publishes.

License

MIT.