# Brain Taxonomist

Filing gate for ALL brain writes.

- Repository: https://github.com/garrytan/gbrain (31427 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add garrytan/gbrain --skill brain-taxonomist -g -a claude-code -y`
Codex: `npx skills add garrytan/gbrain --skill brain-taxonomist -g -a codex -y`
Cursor: `npx skills add garrytan/gbrain --skill brain-taxonomist -g -a cursor -y`
Gemini CLI: `npx skills add garrytan/gbrain --skill brain-taxonomist -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add garrytan/gbrain`

## Description

Filing gate for ALL brain writes. Consulted before creating any new brain page to determine the correct path. Reads the ACTIVE schema pack via `gbrain schema show --json`, no hardcoded directory table. Also runs periodic taxonomy drift detection via `gbrain schema review-orphans`.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# brain-taxonomist

## Purpose

**Gate function:** Before creating ANY new brain page, consult this skill to determine the correct filing path. This prevents misfiling at write time rather than cleaning up drift after the fact.

**Drift function:** Periodic scan for pages that have outgrown their current location.

## Contract

This skill guarantees:
- Every new page is filed at the path determined by the ACTIVE schema pack, never against a hardcoded directory table baked into this skill.
- The decision is reproducible: invoking brain-taxonomist twice on the same content produces the same recommended path.
- Ambiguous cases surface to the user via `skills/ask-user/` rather than silently picking a default.
- Per-source overrides via `--source <id>` are honored, multi-brain users (Persona B) get a different recommendation per source if their packs diverge.
- When no matching `page_types[]` entry exists in the active pack, the skill signals to EIIRP Phase 3 (SCHEMA CHECK) rather than picking the closest-fitting fallback.

## Critical: this skill reads the ACTIVE schema pack as data

`brain-taxonomist` has NO hardcoded directory table. Every decision is
driven by `gbrain schema show --json`. This means:
- A user who runs `gbrain schema use gbrain-recommended` gets the full
  recommended directory set (deal, meeting, concept, project, source,
  daily, personal, civic, original, place, trip, conversation, writing,
  plus all gbrain-base types).
- A user who authored a custom pack via `gbrain schema init` + edit gets
  filing recommendations based on THEIR taxonomy, not gbrain's defaults.
- Per-source overrides (tier 3 in the 7-tier resolution chain) are honored
  when `--source <id>` is passed to brain-taxonomist.

This is the single-source-of-truth principle (D9 from the v0.39 plan-eng-review).

## When to Consult (MANDATORY)

Run the taxonomist check before writing to the brain in these cases:

The rest: https://github.com/garrytan/gbrain/blob/HEAD/plugin/skills/brain-taxonomist/SKILL.md