> ## Documentation Index
> Fetch the complete documentation index at: https://project-brain.rocheaiops.net/llms.txt
> Use this file to discover all available pages before exploring further.

# Phase 4: text Learning Spine

> Private text teaching, fresh-session recall, correction lineage, recovery, and Basic Memory isolation.

**Acceptance commit:** `13fa057`. Phase 4 established the core vertical proof: teach → persist → close → fresh-session recall → explain → correct → preserved SUPERSEDED predecessor → current ACTIVE result.

T01–T09, T15/T16, D10/D11, and clean-environment deployment passed. The API stayed loopback-only and PostgreSQL remained internal. Backup/isolated restore verified both current and historical lineage. See [defects](/validation/defect-register) and `docs/evidence/phase-4/2026-09-10-text-learning-spine/results.md`.