nah

expensive mistakes stop here
a guard that blocks catastrophic agent actions

nahguard.ai • what it blocks • how it compares • how it decides • install • extend • threat model

claude code · codex · cursor · pi · + 11 more

nah is a guard that sits in your coding agent's hook path and reads tool calls before they run. It blocks the calls it can prove are disasters and never approves anything: everything else goes to your runtime's normal permissions.

nah is just one Rust binary: a verdict is deterministic and needs no LLM. Extensions are just programs. Point your agent to nah's docs and ask it to build a custom nah guard.

It knows a disaster when it sees one.

47 guards, 29 on by default, covering seven classes of disaster: execution hijacks, secret theft, filesystem destruction, git disasters, infrastructure, storage, and backup teardown, package-registry operations, and host power and service-stop actions.

Guard	Blocks
exec-remote	Execution of a payload visibly obtained from the network.
exec-decoded	Execution reached from a visible decode stage.
exec-obfuscated	Encoded, pattern-selected, or unresolved execution.
exec-network-shell	Shells attached to a network connection, including netcat, socat, and shell redirection.
secrets-env	Reads of .env files and sensitive basenames, including contents from Git history, plus direct output of catalogued credential environment variables.
secrets-credentials	Reads or writes of private-key and credential-store paths, including content reads from Git history; deleting or moving away private keys; metadata or value reads of the macOS keychain.
secrets-exfil	A visible flow from a sensitive source to a network stage.
secrets-store-delete	Remaining reviewed secret-store deletion with recoverable or context-dependent semantics. Off by default.
secrets-store-destroy	Proven permanent secret-store destruction: Vault version/metadata/engine removal, AWS force and SSM deletion, Google whole-secret deletion, Azure purge, Doppler project/configuration deletion, and 1Password vault deletion.
secrets-store-read	Reviewed value reads across common secret-manager CLIs.
fs-system-tree	Deletion, proven root-entry relocation, or recursive permission changes selecting the filesystem root or a system tree.
fs-home	Deletion or recursive permission changes selecting the home root.
fs-outside-workspace-delete	Recursive deletion outside the active project, except under reviewed temporary roots. Off by default.
fs-permission-weaken	chmod modes that provably grant world-write or setuid/setgid permission. Off by default.
fs-project-root	Concrete Project-scoped recursive deletion or known recursive permission changes selecting the exact project root or its exact *, .*, or {*,.*} root-wide patterns. find -delete without an explicit start path has no modeled target.
fs-raw-device	Visible writes to, and whole-device destruction of, raw storage devices, and the sysrq trigger.
fs-volume-destroy	Definite logical-volume, storage-pool, and live ZFS dataset destruction.
fs-forkbomb	Structurally recognized shell fork-bomb patterns.
fs-auth-identity	Modification or deletion of reviewed host authentication, identity, and privilege-policy files, including recursive deletion of their parent directories.
fs-shell-profile	Changes to reviewed user shell profile paths. Off by default.
fs-startup-management	Reviewed persistent systemctl, launchctl, and crontab management commands. Off by default.
fs-startup-persistence	Changes to reviewed service, schedule, login, autostart, and loader startup paths.
git-clean-force	An effective forced Git clean selecting the project root.
git-force-push	Git force pushes without lease protection and leased force pushes explicitly targeting main or master.
git-hard-reset	Git hard resets.
git-history-rewrite	Selected unforced Git history rewrites, including rebases, filtering, recovery expiry, aggressive or pruning garbage collection, and leased force pushes, including explicit static refspecs targeting main or master. Off by default.
git-rewrite-force	History rewriting that explicitly bypasses safety or backup checks.
git-metadata	Destructive writes or deletion selecting durable Git history metadata.
git-path-discard	Definite named-path checkout, restore, and same-path git show overwrites. Off by default.
git-protected-push	Pushes whose explicit static refspec targets main or master. Bare pushes remain outside this guard. Off by default.
git-recovery-destroy	Clearing the full stash collection or immediate repository-wide destruction of Git recovery history.
git-ref-delete	Reviewed local and remote ref, stash entry, worktree, and submodule worktree deletion. Off by default.
git-remote-repo-delete	Exact GitHub and GitLab whole-repository deletion through their CLIs and REST routes.
git-remote-resource-delete	Statically targeted GitHub and GitLab hosted-resource deletion through reviewed CLI commands and REST routes. Off by default.
git-worktree-discard	Project-wide checkout or restore, proven forced branch changes, and forced worktree removal or submodule deinitialization.
db-destroy	Dropping, truncating, flushing, resetting, or overwriting live database data, and deleting managed databases. Off by default.
infra-container-reset	Podman commands that reset the complete local or selected runtime state.
infra-container-volume-delete	Broad unused-volume cleanup through reviewed Docker and Podman prune commands, and Compose down -v/rm -v volume removal. Off by default.
infra-iac-destroy	Fully visible Terraform, OpenTofu, and Pulumi whole-stack destruction. Off by default.
infra-k8s-delete	Static namespace, reviewed cluster-resource, and bulk reviewed namespaced-resource deletion through kubectl. Off by default.
storage-backup-destroy	Complete backup-repository or all-backup deletion through reviewed Borg, Restic, and Velero commands.
storage-recursive-delete	Broad remote deletion and destination-deleting synchronization through reviewed cloud and sync CLIs. Off by default.
storage-snapshot-delete	Reviewed snapshot, archive, volume, and retention deletion. Off by default.
registry-publish	Reviewed package publication commands. Off by default.
registry-unpublish	Reviewed package unpublish, irreversible RubyGems yank, and published-name owner changes.
sys-power	Fully visible local host shutdown, reboot, halt, and suspend actions.
sys-service-stop	Reviewed service shutdown, target isolation, Podman stop-all or kill-all, and docker stop or docker kill of every listed container. Off by default.

Run nah docs guards to see the full built-in catalog, with each guard's exact scope and three tested examples, plus current custom guard status.

How it compares against similar tools

nah is the most complete coding agent guard, and stacks well with Auto modes