Overview

Agents forget everything between sessions unless you write it down somewhere they'll look. Pinky Brain is Quack's answer: a local search layer over markdown knowledge files, so an agent starting fresh can find what a previous session already learned.

Two levels

• Project level — your workspace's own documentation/ folder: gotchas, patterns, decisions, diary entries specific to this codebase.
• Global level — a ~/.pinky/brain/ folder shared across every project you work on, for knowledge that isn't tied to one codebase.

How search works

Pinky combines classic keyword search (BM25) with semantic vector search, so a query matches on meaning as well as exact words. The index itself (brain.db) is disposable — it's rebuilt from the markdown files any time, so the .md files are always the real source of truth, never the database.

Why markdown, not a database

Every entry is a plain .md file with YAML frontmatter (type, project, created, tags). You can read, edit, or delete them with any editor — Pinky just makes them searchable.