github-airplane-mode

GitHub Airplane Mode

Purpose

Switch an already-installed local Git and GitHub download guard.

Keep the guard installed and active sessions intact. This skill does not bundle or install low-data, Git/GitHub wrappers, or a native connection-cost detector.

When to use

• Enable protection before a flight or on a metered connection.
• Disable protection after returning online.
• Inspect the current policy or use automatic connection-cost detection.

Workflow

Verify the prerequisite

Operate only on the current machine. Require an already-installed compatible low-data command before running any recipe.

1. Resolve command -v low-data and inspect its file or symlink target. Verify its trusted local source and the mode, status, and exit semantics below. Stop if it is missing, shadowed, unfamiliar, or incompatible; report the prerequisite instead of downloading or replacing it.
2. Inspect the current state with env -u LOW_DATA_ALLOW_NETWORK low-data status.
3. Apply only the requested mode. Interpret "I'm back", "return online", or "remove airplane mode" as off, not removal of the reusable guard.

Switch modes

# Inspect without a per-command override masking the saved policy.
env -u LOW_DATA_ALLOW_NETWORK low-data status

# Force protection for a flight or metered connection.
env -u LOW_DATA_ALLOW_NETWORK low-data on

# Explicitly disable protection after returning online.
env -u LOW_DATA_ALLOW_NETWORK low-data off

# Follow the native connection-cost detector.
env -u LOW_DATA_ALLOW_NETWORK low-data auto

Require these semantics: on forces protection; off explicitly disables it; auto protects constrained or expensive connections and fails closed when native status is unavailable. An unmetered connection is unprotected in auto.

Verify the result

After any change, run both checks with the override unset:

env -u LOW_DATA_ALLOW_NETWORK low-data status
if env -u LOW_DATA_ALLOW_NETWORK low-data active; then
  printf 'active_exit=0 (protected)\n'
else
  active_exit=$?
  printf 'active_exit=%s\n' "$active_exit"
fi

Require active exit 0 for on and exit 1 for off. For auto, report the detected reason and the matching active state. Treat any other exit as a failed check. Do not claim success from the mode-setting command alone.

Keep changes bounded

• Preserve the switch, guards, native detector, and unrelated settings. Use the command to change mode; do not delete the implementation or edit shell startup files to turn it off.
• Limit protection claims to guarded Git history and bulk GitHub repository, release, and artifact downloads. Normal commits, pushes, metadata/API requests, curl, package installs, and model traffic remain allowed.
• Do not claim whole-machine airplane mode, a firewall, or a bandwidth cap. PATH wrappers are not a network boundary. Never bypass them through absolute Git or GitHub CLI binaries, aliases, or custom hooks.
• Allow LOW_DATA_ALLOW_NETWORK=1 command ... only for one explicitly approved command. Never export that override globally.
• Do not pause, resume, kill, or relaunch agent, tmux, terminal, or background sessions. A mode change is not process-control authority.
• Do not change other hosts, credentials, GitHub authentication, proxy settings, or remote repositories.

Inputs

• Requested local operation: status, on, off, or auto.
• Already-installed compatible low-data command and its trusted source.

Outputs

• Saved mode, effective protected/unprotected state, and detected reason.
• Post-change status and active exit-code proof.
• Exact missing prerequisite or failed verification when the operation cannot complete.

Flow

stateDiagram-v2
    [*] --> VerifyInstalledCommand
    VerifyInstalledCommand --> ReportBlocked: missing or incompatible
    VerifyInstalledCommand --> ReadCurrentState: compatible
    ReadCurrentState --> ReportState: status only
    ReadCurrentState --> SetRequestedMode: on, off, or auto requested
    SetRequestedMode --> CheckStatusAndActive
    CheckStatusAndActive --> ReportState: mode and active result agree
    CheckStatusAndActive --> ReportBlocked: unexpected exit or mismatch
    ReportState --> [*]
    ReportBlocked --> [*]