CC Second Brain

Three-tier memory: engram (working) + Obsidian vault (durable) + plugin rules (baseline). Full separation-of-concerns in conventions.md and topic-key-taxonomy.md.

Tier routing — decision tree

Did work just conclude?
│
├─ Is it a one-off observation, decision, or discovery?
│   └─ YES → engram (tier 1) — mem_save with CC topic_key (see taxonomy)
│
├─ Is it a reusable pattern (used or useful in ≥ 2 repos)?
│   └─ YES → Obsidian (tier 2) — Research/Claude-Code/Patterns/{slug}.md
│            with frontmatter auto_generated: false if user-curated
│
├─ Is it repo-specific durable knowledge?
│   └─ YES → Obsidian (tier 2) — Repositories/{org}/{repo}.md
│            or Decisions/NNNN-title.md for ADRs
│
└─ Is it a rule every consumer-repo Claude should follow?
    └─ YES → plugin rules (tier 3) — memory/rules/cc-always.md
             (only the plugin maintainer edits this)

Engram — tier 1 write pattern

Call mem_save with CC topic_key. See topic-key-taxonomy.md for full prefix table.

Required: title, content (What/Why/Where/Learned format). Recommended: topic_key starting with cc/*, type (decision/bugfix/architecture/discovery/pattern/config/preference), scope (project or personal).

Examples:

mem_save({
  title: "Chose protect-sensitive-files hook for all new setups",
  type: "decision",
  topic_key: "cc/hooks/protect-sensitive-files",
  content: "**What**: Default install on every /cc-setup run\n**Why**: Prevents writes to .env / credentials / keys\n**Where**: memory/rules/cc-always.md\n**Learned**: Hook matcher Write|Edit is correct — don't also match MultiEdit, it inherits"
})

Obsidian — tier 2 write pattern

Preferred: use Obsidian MCP tools (mcp__obsidian__*) if loaded — they append/update via the Local REST API.

Fallback: direct Write tool at vault paths.

Auto-generated note frontmatter (consolidator only):

---
auto_generated: true
source: engram
topic_key: cc/patterns/{slug}
reinforcement_count: 7
first_seen: 2026-04-09
last_updated: 2026-04-16
tags: [claude-code, pattern, auto]
---

User-curated note frontmatter:

---
title: {short title}
created: {YYYY-MM-DD}
tags: [claude-code, type/pattern]
---

Durability invariant: notes WITHOUT auto_generated: true are user-curated. Consolidator never overwrites them. If you're writing a note on behalf of the user, use auto_generated: false explicitly.

Plugin rules — tier 3 write pattern

memory/rules/cc-always.md — user-only (edit via /cc-memory edit-always). memory/rules/cc-patterns.md — consolidator-only. memory/rules/DRAFT.md — consolidator-only (conflicts).

Do NOT hand-edit cc-patterns.md or DRAFT.md — the consolidator owns them.

Querying the tiers

Need	Tool
"Have we solved this before?"	mem_search with cc/ prefix hint → mem_context for recent history
"What's the current rule for X?"	Read memory/rules/cc-always.md and memory/rules/cc-patterns.md
"What patterns exist for Y?"	Obsidian MCP search or Grep on Research/Claude-Code/Patterns/
"What does this repo know?"	Read Repositories/{org}/{repo}.md first

/cc-memory subcommands

Subcommand	Action
search <query>	engram mem_search scoped to cc/* keys
export [--domain ...]	write human digest to memory/digests/{date}.md
consolidate	run consolidator: engram → Obsidian + cc-patterns.md
edit-always	open memory/rules/cc-always.md
review	open memory/rules/DRAFT.md (conflicts)
status	show: last consolidation, pattern count, draft count, cc/* observation count

MCP tools the consolidator uses (READ-ONLY on engram)

Tool	Used for
mem_search	Find cc/* observations
mem_get_observation	Fetch full content of a match
mem_context	Recent session context for timing

NEVER used by the consolidator: mem_save, mem_update, mem_delete. Those are Claude-in-session or user-manual operations only.

Common anti-patterns

• Saving to engram without a topic_key for CC work → consolidator can't group observations → pattern never promotes.
• Writing to Repositories/{org}/{repo}.md with auto_generated: true when it's actually hand-curated → consolidator will overwrite it later.
• Editing memory/rules/cc-patterns.md by hand → consolidator will clobber your edits on next run. Put hand-curation in cc-always.md.
• Skipping mem_session_summary at end of session → next session starts blind; consolidator has less to work with.