command

Shell out to an external CLI per matched file. Exit 0 is a pass; non-zero is one violation whose message is the (truncated) stdout+stderr. Working directory is the repo root; stdin is closed.

- id: workflows-clean
  kind: command
  paths: ".github/workflows/*.{yml,yaml}"
  command: ["actionlint", "{path}"]
  level: error

Argv tokens accept the same path-template substitutions as pair and for_each_dir: {path}, {dir}, {stem}, {ext}, {basename}, {parent_name}. The first token is the program (looked up via PATH if it’s a bare name).

Environment threaded into the child:

Var	Value
ALINT_PATH	matched path (relative to root)
ALINT_ROOT	absolute repo root
ALINT_RULE_ID	the rule’s id:
ALINT_LEVEL	error / warning / info
ALINT_VAR_<NAME>	one per top-level vars: entry
ALINT_FACT_<NAME>	one per resolved fact, stringified

timeout: <seconds> (default 30) bounds each invocation; past the limit the child is killed and a violation reports the timeout.

Trust gate. Every process-spawning rule kind — command, generated_file_fresh, and command_idempotent — is allowed only in the user’s own top-level config. Any of them introduced via extends: (local file, HTTPS URL, or alint://bundled/) is a load-time error — the same gate that protects custom: facts. Adopting a published ruleset must never imply granting it arbitrary code execution.

Path confinement + allow_out_of_root. Every config-declared path is confined to the repo root — a rule can’t read or resolve a file outside the tree it was pointed at. The top-level-only allow_out_of_root: key relaxes this for reads (json_schema_passes schema_path:, pair_hash target:, registry_paths_resolve source:) when a trusted config must reference an external file. It is rejected from extends:’d rulesets (same trust model as the spawn gate above) and a permitted read emits a note. See Configuration → allow_out_of_root.

--changed interaction: command is a per-file rule, so under alint check --changed it spawns only for files in the diff. The expensive check is automatically incremental in CI.

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Options

Option	Type	Required	Default	Description
command	list of string	yes		Argv tokens. The first token is the program (looked up via PATH if it’s a bare name); remaining tokens accept {path} and friends.
timeout	integer (>= 1)		null	Per-file timeout in seconds. Default 30. Past this, the child is killed and a violation reports the timeout.

Plus the common paths, level, id, and when fields. This table is generated from the JSON Schema; option types and defaults are authoritative.