Rules and Matching

Rules are evaluated top to bottom. A match can be exact or wildcard-based, and the first matching rule wins.

The schema supports matching by tool, host, port, method, path, query, headers, and a when expression. The SDK policy helpers also support richer client-side match conditions such as pattern, contains, amount_gt, amount_lte, and agent_id.

Examples:

- id: allow-http-get
  match:
    tool: "http/get"
    when: "true"
  effect: permit

- id: block-all-shell
  match:
    tool: "shell/*"
    when: "true"
  effect: deny

- id: require-approval-for-refunds
  match:
    tool: "stripe/refund"
    when: "args.amount > 100"
  effect: defer

Common gotcha: do not place a wildcard deny before the specific allow rules that should win first. The engine does not sort for you; it obeys document order.

For a richer matching model, compare the YAML schema page with the typed SDK helpers in SDK Client Reference.