Adds a floor below --yolo: a tiny set of commands so catastrophic they
should never run via the agent, regardless of --yolo, gateway /yolo,
approvals.mode=off, or cron approve mode. Opting into yolo is trusting
the agent with your files and services — not trusting it to wipe the
disk or power the box off.
The list is deliberately small (12 patterns), covering only
unrecoverable ops:
- rm -rf targeting /, /home, /etc, /usr, /var, /boot, /bin, /sbin,
/lib, ~, $HOME
- mkfs (any variant)
- dd + redirection to raw block devices (/dev/sd*, /dev/nvme*, etc.)
- fork bomb
- kill -1 / kill -9 -1
- shutdown, reboot, halt, poweroff, init 0/6, telinit 0/6,
systemctl poweroff/reboot/halt/kexec
Recoverable-but-costly commands (git reset --hard, rm -rf /tmp/x,
chmod -R 777, curl | sh) stay in DANGEROUS_PATTERNS where yolo can
still pass them through — that's what yolo is for.
Container backends (docker/singularity/modal/daytona) continue to
bypass both hardline and dangerous checks, since nothing they do can
touch the host.
Inspired by Mercury Agent's permission-hardened blocklist.
Add approvals.cron_mode config option that controls how cron jobs handle
dangerous commands. Previously, cron jobs silently auto-approved all
dangerous commands because there was no user present to approve them.
Now the behavior is configurable:
- deny (default): block dangerous commands and return a message telling
the agent to find an alternative approach. The agent loop continues —
it just can't use that specific command.
- approve: auto-approve all dangerous commands (previous behavior).
When a command is blocked, the agent receives the same response format as
a user denial in the CLI — exit_code=-1, status=blocked, with a message
explaining why and pointing to the config option. This keeps the agent
loop running and encourages it to adapt.
Implementation:
- config.py: add approvals.cron_mode to DEFAULT_CONFIG
- scheduler.py: set HERMES_CRON_SESSION=1 env var before agent runs
- approval.py: both check_command_approval() and check_all_command_guards()
now check for cron sessions and apply the configured mode
- 21 new tests covering config parsing, deny/approve behavior, and
interaction with other bypass mechanisms (yolo, containers)
