Files
ducoterra 144e322391 Add --publish: the one ingress control
Everything else in the file gates egress, which left an everyday request unanswered: the
agent starts a dev server inside the sandbox and a human wants to look at it. This puts a
listener on the host that forwards into the container, so a browser, curl or an API
tester reaches the server the sandboxed process runs.

`--publish [ADDR:]HOST:CONTAINER`, config `publish` and AISB_PUBLISH, repeatable, with the
cost named in the flag: it is ingress, so whatever that server serves is reachable from
the address it binds. The default address is 127.0.0.1 because a bare podman -p binds
every interface (measured) -- a port committed in a repo config must not quietly be a port
on the LAN. publish_addr changes the default machine-wide; a spec with a non-loopback
address warns on every run. The grammar is smaller than podman's on purpose: one port per
entry, no ranges, no /udp, no `*` -- this list is reviewed line by line, and typing
0.0.0.0 is the whole warning. An address means three parts, so `127.0.0.1:8000` is refused
rather than guessed. No -p alias: that flag belongs to the harness (claude -p prints).

Fail closed, as elsewhere: --net none cannot forward a port and podman discards the
mapping while starting the container anyway, so "it ran" would mean "nothing is
listening"; a host port already in use is named before the container starts, not after a
build; pick_port() will not hand the gate a port this run publishes. The container is
labelled with the ports it was given, and doctor reports them.

Inside, publish_rules() accepts tcp on the published ports in the input chain and never
the output one. Measured (docs/networking.md): pasta delivers the connection over
loopback, so that rule counts 0 packets on the reference host; it is there for a host or a
bridge network that delivers on the interface, and so that `nft list table inet aisb`
answers "what can reach this container". The ports are validated again inside the
entrypoint, because a ruleset is not somewhere to splice an unvalidated string. And the
measurement that makes a configured preview look broken: a server bound to 127.0.0.1
inside answers inside and refuses the published port outside, so dev servers must bind
0.0.0.0 -- both skills say so in the change that writes the port.

Tests. Unit: the grammar and every port list that looks right and is not, config/env/flag
precedence and dedup, the canonical spec in --print-policy, the `# ingress:` header, the
flags reaching the invocation before the image, egress enforcement byte-identical with a
port open, which chain the rule lands in and that a non-numeric port never reaches nft as
code. e2e (tests/e2e/13_publish.sh): one real container with enforce=nft where the host
gets its 200 and the same run still refuses a domain outside the allowlist at 403, the
server runs as uid 1000 with no capabilities so it cannot widen its own port, and the host
listener is gone when the container exits.

LLM-Generated: true
2026-10-30 22:53:57 -04:00

15 KiB

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

Ports: two directions, two answers

Outbound — a service on your machine (dev postgres, redis, a mock API, a local model server). That is egress, so it is an allow entry, not a flag. 100.64.0.1 is the address that stands for the host's loopback inside the container:

# .ai-sandbox/allow
100.64.0.1:5432            # postgres from `docker compose up db`, on the host

# .ai-sandbox/config -- point the app at the mapped address (no secret is a URL like this)
env = DATABASE_URL=postgresql://dev@100.64.0.1:5432/app_dev
# HTTP on anything but 80/443/8443 also has to skip the proxy, or the gate is asked for it:
env = NO_PROXY=100.64.0.1,localhost,127.0.0.1,::1
env = no_proxy=100.64.0.1,localhost,127.0.0.1,::1

Inbound — a server the sandbox runs, to be seen from the host. Publish it. Bound to loopback by default, so http://127.0.0.1:8000 in your browser works and nothing on your network can reach it:

# the one-off preview: the agent runs the server, you look at it
ai-sandbox --allow aipi.reeseapps.com --publish 8000 -- npm run dev -- --host 0.0.0.0

# a host port that is free, a different container port
ai-sandbox --publish 18080:3000 -- npm run dev -- --host 0.0.0.0

# from a project's own config, so `ai-sandbox` alone is the invocation
#   .ai-sandbox/config:  publish = 8000
#                        publish = 18080:3000

Four things worth knowing before it looks broken (all measured, all in networking.md):

  • the server must listen on 0.0.0.0 inside — --host 0.0.0.0, uvicorn --host 0.0.0.0, runserver 0.0.0.0:8000. A 127.0.0.1-only server answers inside and refuses the published port.
  • egress is unaffected. A published port is ingress: the run keeps its allowlist, its unprivileged uid and its ruleset, and the ruleset names the ports it opened.
  • --net none refuses to publish rather than start with nothing listening; a host port that is already taken is named before the container starts, not after the build.
  • a non-loopback bind (publish = 0.0.0.0:18080:3000) means exactly what it says: anything that can route to this machine can reach that server. It warns, and it does not belong in a committed config — that file outlives the run that justified it.

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=$(pass aipi/dev-token)
    ai-sandbox --allow aipi.reeseapps.com --allow pypi.org --allow files.pythonhosted.org \
               --install python3-pip --install ripgrep --env AI_API_TOKEN "$@"
}

A new --install set is a new image tag, so the first run after changing it builds: that one run says which packages are going in and reports every step until the image exists (AISB_BUILD_OUTPUT=quiet if you would rather it did not talk). Every later run starts without a word about the image, because there is nothing left to do.

doctor, inspect, clean and the rest of ai-sandbox work unchanged underneath it — --status prints the policy the launcher will apply, without applying it.