---
id: "0006"
date: 2026-06-03
status: Superseded
supersedes:
superseded-by: "0010"
affected-paths: []
affected-components: []
migration_confidence: medium
migration_source: "docs/memory-system/03-architecture-decisions.md### ADR-006 — QMD as the (deferred) semantic-over-knowledge layer"
---

# 0006 — QMD as the (deferred) semantic-over-knowledge layer

## Context

When ADR-005's structured-only proves insufficient, we want a set-and-forget
  semantic layer over the vault, local and Docker-free.

## Decision

Earmark **QMD** (github.com/tobi/qmd) for that role; do **not** install yet.
- **Rationale**: Local markdown search using **SQLite + FTS5/BM25 + local vector embeddings
  (EmbeddingGemma-300M GGUF) + LLM rerank**; CLI + optional **MCP server**; no Docker, no API
  keys. Validates that SQLite + a local vector model suffices (no Milvus/Postgres for
  knowledge). Complements the tag index (QMD filters by path/collection context, not
  first-class frontmatter tags), so it adds semantic recall without replacing structured
  filtering.

## Consequences

QMD was earmarked (but not installed) as the future semantic-over-knowledge layer to complement the tag index once structured-only search proved insufficient, validating that SQLite plus a local vector model would suffice without Milvus/Postgres. This earmarking was later superseded by ADR-010, since Graphify's knowledge graph fills the semantic-recall role via traversal/explain without needing a separate vector system.

## Alternatives rejected

Pointing memsearch at the vault (mixes episodic and knowledge
  corpora; its filtering is path-prefix not tags). A bespoke embedding index (reinvents QMD).
