ai-sandbox-autophase could sit forever, printing nothing, in two places that are both before the first unit -- which is why both looked like a script that "does nothing". The rc probe ran `timeout 15 bash -ic` in front of the user's terminal. An interactive bash calls tcsetpgrp() to take that terminal, is in its background, and is stopped for trying; a stopped process does not take SIGTERM, so the timeout waited in front of it and the driver waited on the command substitution behind it. It now runs in its own session (setsid), with stdin closed, under `timeout -k`, and reads the definition from a temp file rather than a pipe, because a grandchild an rc file leaves behind holds a pipe's EOF open long after the shell it came from has been reaped. A launcher is called *with* the run, and a function ending at `--env NAME` -- the shape everyone writes for typing by hand, including every example this repo printed -- discards the flags and the in-container command. The container then starts the image's default harness with no prompt and, with --no-interactive gone, the terminal attached: an agent waiting for keystrokes behind a pipe nobody reads. `ap_forwards_args` checks the captured definition, --status and the preflight name it with the one-line fix, and every child now starts with stdin on /dev/null so a launcher cannot put the sandbox back on the keyboard. Aliases and whole command lines need no forwarding: the shell appends the words to those. Tests: a launcher fixture that drops its arguments, one that leaves a process behind, and shape assertions on ap_probe_rc. LLM-Generated: true
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Recipes
Concrete invocations. pi below is whatever you aliased to ai-sandbox.
A first session
cd ~/Projects/myapp
ai-sandbox doctor # is this machine ready?
pi --allow aipi.reeseapps.com --env AI_API_TOKEN
With your pi config bridged, the token is found on its own, so the allowlist is the only thing you have to say:
pi --allow aipi.reeseapps.com
Same thing, but remembered by the repo (so teammates review the policy, not just your shell history):
mkdir -p .ai-sandbox
printf 'aipi.reeseapps.com\n' > .ai-sandbox/allow
pi
Pi's own configuration
The bridge rewrites your host ~/.pi/agent/{models,settings}.json instead of copying
it: providers, models, thinking budgets and preferences come along, the credential
becomes "$AI_API_TOKEN", and anything that only works on the host (a !command
header, a path into ~) is dropped with a warning. auth.json is never bridged.
# the everyday case: same provider as the host, token from the environment
pi --allow aipi.reeseapps.com
# a model your gateway serves, chosen per run
pi --allow aipi.reeseapps.com --model juggernaut
# keep the model's endpoint pinned by IP as well, on a LAN inference host
pi --allow aipi.reeseapps.com --allow 10.20.0.7:11434
# a different variable name for the credential
pi --allow aipi.reeseapps.com --pi-token-env GW_TOKEN
# do not hand the token over automatically: the run then fails closed unless you
# pass it yourself, which is what you want in shared scripts
pi --allow aipi.reeseapps.com --env AI_API_TOKEN --no-pi-token-env
# no bridge: pi starts with its own defaults inside the volume (and no thinking policy)
pi --no-pi-config --allow aipi.reeseapps.com
models.json is kept in step with the host unless you edit it in the sandbox, where your
edit then wins; deleting it inside the sandbox re-seeds it. settings.json is merged per
key, so a preference you changed in the sandbox stays changed and every one you did not
touch follows the host again.
How hard it thinks
defaultThinkingLevel is policy, not preference: xhigh unless you say otherwise, and
re-applied every run rather than remembered from whatever the last sandbox set.
# the everyday case: xhigh
pi --allow aipi.reeseapps.com
# one-off: the top of pi's range, or no reasoning at all for a mechanical job
pi --thinking max --allow aipi.reeseapps.com
pi --thinking off --net allow --allow registry.npmjs.org -- npm ci
# let settings.json decide, the way it did before this was policy
pi --thinking host --allow aipi.reeseapps.com
# per repo, chosen by .ai-sandbox/config
# thinking = high
Nothing is written for codex, claude or a command after --: those read their own
configuration and ai-sandbox does not touch it.
Your skills and standing instructions
~/.agents is shared read-only at /home/sandbox/.agents by default, so the sandboxed
harness finds the same skills, prompt templates and AGENTS.md you use on the host.
A project's own .agents/ needs nothing: it arrives with the project mount, and harnesses
that read both see the project's alongside yours.
# the everyday case: your skills are simply there
pi --allow aipi.reeseapps.com
# a run where the harness should not have them: reviewing untrusted code, or a
# skills set that mentions internal hosts you would rather it not repeat back
pi --net none --no-agents -- bash -lc 'make lint'
# a curated set for sandboxes -- e.g. host skills stay yours, this dir is what you share
pi --agents-dir ~/.config/ai-sandbox/agents --allow aipi.reeseapps.com
# two sets, per trust level, chosen by config file in a repo
# .ai-sandbox/config: agents_dir = ./.agents-shared
It is read-only and there is no flag to change that: a skill is an instruction you
follow on the host later, so letting a sandbox write one would let it persist past the
run. If a workflow really needs to author skills, do it in the project directory and
move the result into ~/.agents yourself, where you can read it first.
Per harness
# pi (baked into the image, config bridged)
pi --allow aipi.reeseapps.com
# pi with a model chosen on the command line
pi --harness 'pi --model turbo' --allow aipi.reeseapps.com
# a gateway that speaks a different protocol still needs only its host
pi --allow gateway.internal:8443 --env AI_API_TOKEN
# OpenAI Codex CLI / Claude Code: they read their own config files, so mount or
# generate what they need and allow their endpoints; the pi bridge does not apply
pi --allow chatgpt.com --env CODEX_API_KEY
pi --allow api.anthropic.com --env ANTHROPIC_API_KEY
# just a shell in the sandbox
pi --shell
# any other build/test command, no network needed
pi --net none -- make test
Per ecosystem
Only the endpoints the tool actually needs. Everything else stays blocked, so a typosquatted package from an unexpected host fails loudly instead of quietly working.
# npm / node
pi --allow registry.npmjs.org --allow nodejs.org --allow github.com
# python: pypi needs both of these (the CDN that serves the files is separate)
pi --allow pypi.org --allow files.pythonhosted.org
# rust
pi --allow crates.io --allow static.crates.io --allow index.crates.io
# go
pi --allow proxy.golang.org --allow sum.golang.org
# docker/podman images from within a build
pi --allow registry-1.docker.io --allow auth.docker.io --allow production.cloudflare.docker.com
# a project that also needs its dev database (non-HTTP: pinned IP + port)
pi --allow aipi.reeseapps.com --allow 10.20.0.5:5432
Git
# fetch/push over https with a token in the environment
pi --allow github.com --env GH_TOKEN -- git push origin main
# ssh: the key has to be mounted deliberately (an explicit, reviewable grant)
pi --allow github.com --mount ~/.ssh:ro -- git push origin main
# read-only view of a sibling repo for context
pi --allow aipi.reeseapps.com --mount ../docs:/docs:ro
Tightening a run
# nothing persistent, nothing readable, nothing writable outside the repo
pi --net none --ephemeral-home --read-only -- make build
# an entirely blank sandbox for untrusted code: no project, no home, no skills
pi --net none --no-cwd --ephemeral-home --read-only --no-agents -- bash
# CI-ish: refuse to start if the policy or environment is not exactly right
pi --strict-args --net allow --allow-file .ai-sandbox/allow --env-file .ci/env -- npm ci
Long-lived gate shared by several sandboxes
ai-sandbox gate up --allow aipi.reeseapps.com --allow registry.npmjs.org
# name=aisb-gate
# port=18081
# proxy_env=export HTTPS_PROXY=http://100.64.0.1:18081
ai-sandbox --proxy 100.64.0.1:18081 --allow aipi.reeseapps.com --shell
ai-sandbox gate logs # what did it allow/deny?
ai-sandbox gate down
Debugging
ai-sandbox --dry-run --allow example.com --env KEY # the exact podman invocation
ai-sandbox --print-policy # effective policy, no secrets
ai-sandbox --print-entrypoint | less # the enforcement script
ai-sandbox --keep --net none -- false # leave the container for forensics
ai-sandbox ps
AISB_GATE_KEEP=1 pi --allow example.com --shell # keep the gate after exit
ai-sandbox clean --all
# "the ruleset would not install" (exit 77): check the host
podman info | grep -i rootless
grep "$(id -un)" /etc/subuid
Making it the default for a project
.ai-sandbox/config:
net = allow
harness = pi
cpus = 8
memory = 8g
mount = ../specs:/specs:ro
env = AI_API_TOKEN
.ai-sandbox/allow:
aipi.reeseapps.com
registry.npmjs.org
Then pi alone in that directory is the whole invocation — and because both files
are in the repository, the sandbox policy gets reviewed with the code.
An unattended pipeline: phases in the sandbox, pushes on the host
The nightly case: .agents/phases/todo/ full of task files, nobody watching, an
agent that must not be able to reach the git remote or touch the host.
# ~/.bashrc.d/ai-sandbox.bash -- the launcher, the way you already write it, plus the
# "$@" that lets a run hand it the command to sandbox
sandbox-pi () {
export AI_API_TOKEN=$(pass aipi/dev-token)
ai-sandbox --allow aipi.reeseapps.com --allow github.com \
--allow pi.dev --allow release-assets.githubusercontent.com \
--env AI_API_TOKEN "$@"
}
A function written for typing by hand usually stops at --env AI_API_TOKEN, and that is
the one thing the driver cannot work with silently: everything after the function name is
the run, so dropping it starts the image's default harness with no prompt. With a terminal
behind it that is an interactive agent waiting for input, its output going into a pipe the
driver is reading — a run that appears to do nothing at all. --status names a launcher
that takes no arguments and the preflight refuses it; the fix is the "$@" above.
cd ~/Projects/foo
ai-sandbox-autophase --status # what it resolved, what is pending, the git plan
ai-sandbox-autophase --dry-run # the exact child and gate commands, nothing run
ai-sandbox-autophase # every pending task, in pipeline order
What it does with that function is the interesting part. A script cannot see an interactive shell's functions, so it reads the rc files, takes the definition, and starts each child as:
sandbox-pi --no-tty --no-interactive -- pi --no-approve --session-dir .agents/phase-sessions --name <unit> --mode json <prompt>
pass runs again per unit, so a run that starts at 23:00 is not holding a token
fetched at 09:00. Reading the definition is all the probe does: --status and
--dry-run never call the launcher, fetch a token, build an image or start a
container. It reads it in a session of its own with no stdin — an interactive bash
started from a terminal tries to take that terminal, gets stopped for trying, and a
stopped process does not take the timeout meant for it. Every child is started with its
stdin on /dev/null for the same reason in the other direction: nothing inside the
sandbox can be waiting for your keyboard.
| you want | flag |
|---|---|
| a different launcher | --pi-cmd sandbox-claude, --pi-cmd pi, or a whole command line |
| the function somewhere else | --rc-files ~/.bashrc.d/zz-ai.bash |
| fewer flags of its own | --sandbox-args '' (the defaults are --no-tty --no-interactive) |
| the gate on the host, because the toolchain lives there | --validate-in host (warns: the gate file is in the writable mount) |
| one task, one phase, a short run | --unit 03_api/02_routes.md, --phase 03_api, --max-units 4 |
| commits that stay local while you watch | --no-push |
| no warm-up container (it costs a build the first time) | --no-preflight |
Where the work goes when it finishes: the executor agents never commit; the driver commits each completed phase on the host and pushes it, checks again before starting the next phase, and pushes whatever is left at the end of the run. A failed push stops the run and prints the command that finishes it — the commit is never lost, and the next run's push sweeps it up:
[2026-10-28 02:14:07] pushing 1 unpushed commit(s) on main (between 03_api and 04_docs)
(pushed: 9f1c2ab phase: 03_api)
Inside the sandbox the agent has the repository but not the remote, and it is told so
in its own prompt (--no-notes to drop that block) — git status, git diff, git log work; git push, fetch, pull and clone <url> are not attempted, so no
fixer round is spent rediscovering that. That is also why the gate runs in the sandbox:
.agents/validate.sh is inside the writable mount, and a jailer the prisoner can edit
is not a jailer.
One consequence of committing out here is worth naming: a repository is not only what
git records, it is what git runs — .git/config, and .git/hooks/ especially. So
the driver's git calls run with an empty hooks path, no pager, no system config and no
ext:: transport, and the run refuses to deliver if a sandboxed unit changed either:
✗ ERROR: refusing to deliver (commit/push) -- the sandbox changed this repository's own git configuration.
look at it by hand: git config --local --list; ls -l .git/hooks
if the change was yours: re-run with --trust-git-changes
The commits and the work stay exactly where they are; nothing is pushed and no hook runs either way.
A project whose tests need something the image lacks gets it from the launcher:
sandbox-pi () {
export AI_API_TOKEN=$(pass aipi/dev-token)
ai-sandbox --allow aipi.reeseapps.com --allow pypi.org --allow files.pythonhosted.org \
--install 'python3-pip ripgrep' --env AI_API_TOKEN "$@"
}
doctor, inspect, clean and the rest of ai-sandbox work unchanged underneath it —
--status prints the policy the launcher will apply, without applying it.