#+TITLE: SKILL: Protocol Validator (org-skill-protocol-validator.org)
#+AUTHOR: Agent
#+FILETAGS: :system:protocol:validation:
#+PROPERTY: header-args:lisp :tangle ../lisp/security-validator.lisp

* Overview
The Protocol Validator enforces schema compliance on every message entering or leaving the cognitive pipeline. It checks that messages are valid plists, that they have the required ~:type~ and ~:payload~ fields, and that the type is one of the known types (~:REQUEST~, ~:EVENT~, ~:RESPONSE~, ~:LOG~, ~:STATUS~). This prevents malformed messages from crashing the pipeline and ensures backward compatibility when the protocol evolves.

* Implementation

** Validation Logic
#+begin_src lisp
(defun validator-protocol-check (msg)
  "Enforces structural schema compliance on protocol messages."
  (validate-communication-protocol-schema msg))
#+end_src

** Skill Registration
#+begin_src lisp
(defskill :passepartout-security-validator
  :priority 95
  :trigger (lambda (ctx) (declare (ignore ctx)) t)
  :deterministic (lambda (action ctx)
                   (declare (ignore ctx))
                   (handler-case
                       (progn (validator-protocol-check action) action)
                     (error (c)
                       (list :type :LOG :payload (list :level :error :text (format nil "Protocol Violation: ~a" c)))))))
#+end_src