Classification Rules

Use classification rules when nah should recognize project-specific commands or when your machine needs a personal override for a command prefix.

Adding commands to existing types

Use the classify config key to map command prefixes to action types:

# ~/.config/nah/config.yaml
classify:
  container_destructive:
    - "docker rm"
    - "docker system prune"
    - "kubectl delete"
  filesystem_delete:
    - "terraform destroy"
  db_write:
    - "psql -c DROP"
    - "mysql -e DROP"

Each entry is a prefix. "docker rm" matches docker rm my-container, docker rm -f abc, and similar commands.

CLI shortcut:

nah classify "docker rm" container_destructive
nah classify "terraform destroy" filesystem_delete

Creating custom action types

You can use any string as an action type. It does not have to be one of the built-in types:

nah classify "terraform" infra_modify
nah deny infra_modify

nah asks for confirmation because infra_modify is not a built-in type. Custom types default to ask policy.

Three-phase lookup

Global classify: entries are checked before built-in classifiers. They are personal or organization-level overrides, so they can intentionally shadow finer-grained built-in behavior.

# Global config: this overrides the built-in curl flag classifier
classify:
  network_outbound:
    - curl    # all curl commands become network_outbound, even curl -X POST

Warning

A single-token global entry like curl will shadow the built-in flag classifier that distinguishes curl (read) from curl -X POST (write). Use nah status to see shadow warnings.

Built-in classifiers and built-in prefix tables run after global overrides. Project .nah.yaml classify entries run only when the active project config root is trusted with nah trust-project. Until then, nah shows those entries as ignored in nah status and does not use them at runtime.

For the full lookup order, see How it works.

Global vs project classify

Aspect	Global	Project
Phase	1 (first)	3 (last)
Can override built-in	Yes	Yes, after nah trust-project
Can override built-in classifier functions	Yes	No
Use case	Personal preferences, org standards	Project-specific commands
Security	Trusted (your machine)	Ignored until the exact project root is trusted

Example: project-specific rules

# .nah.yaml (in project root)
classify:
  db_write:
    - "psql -c ALTER"
    - "psql -c DROP"
  filesystem_delete:
    - "make clean"

actions:
  db_write: block    # tighten: block all DB writes in this project

Project config can tighten actions (for example, escalate ask to block) by default. Relaxing policy or activating project classify requires trusting that exact project root:

nah trust-project
nah classify "migrate-prod" db_write --project

See Configuration overview for Git, non-Git, and nested config behavior.

Checking your rules

# See all custom rules with shadow warnings
nah status

# See all types with override annotations
nah types

# Test a specific command
nah test "docker rm my-container"

nah status shows shadow warnings when your global classify entries override finer-grained built-in rules or classifier functions. Use nah forget <prefix> to remove a shadow.