using-cortex

# Using Cortex — Vault-First Operating Discipline The cortex vault at the path provided by the SessionStart hook is the user's **external memory**. It contains distilled Notes, Projects, Weekly reports, and Raw session transcripts accumulated over months of work. The user's questions are usually grounded in that prior context — even when they don't say so. ## The Prime Rule **Before answering any non-trivial question, scan whether the cortex vault might already contain relevant prior knowledge. If yes, search it FIRST via `cortex-query` — before reasoning from scratch, before asking clarifying questions, before exploring the codebase.** The cost of an unnecessary cortex query is ~2 seconds. The cost of re-deriving an answer the user already wrote down is much higher: wasted turns, drift from the user's actual mental model, and the implicit message "I didn't bother to check what you told me last week." ## When to Search Cortex Proactively Trigger `cortex-query` BEFORE responding when ANY of these are true: 1. **Topic match.** The user's request mentions a topic that appears in the SessionStart hook's vault topic list (Notes/ or Projects/ entries). 2. **Domain match.** The request touches an ongoing project, internal company tooling, plugin development, NAS debugging, DSM/SRM workflows, or any domain the user is known to work in. 3. **Reference signal.** The user says things like "之前那個", "上次的", "我記得有", "我們討論過", "那個 ticket", "the project", "the issue" — the...