The Brain-Agent Loop

Goal

Every conversation makes the brain smarter. Every brain lookup makes responses better. The loop compounds daily.

What the User Gets

Without this: the agent answers from stale context. You discuss a deal on Monday, and by Friday the agent has forgotten. Every conversation starts from zero.

With this: six months in, the agent knows more about your world than you can hold in working memory. It never forgets. It never stops indexing.

The Loop

Signal arrives (message, meeting, email, tweet, link)
  │
  ▼
DETECT entities (people, companies, concepts, original thinking)
  │  → spawn sub-agent (see entity-detection.md)
  │
  ▼
READ: check brain FIRST (before responding)
  │  → gbrain search "{entity name}"
  │  → gbrain get {slug} (if you know it)
  │  → gbrain query "what do we know about {topic}"
  │  → full protocol: brain-first-lookup.md
  │
  ▼
RESPOND with brain context (every answer is better with context)
  │
  ▼
WRITE: update brain pages (new info → compiled truth + timeline)
  │  → gbrain put {slug} (update page)
  │  → add_timeline_entry (append to timeline)
  │  → add_link (cross-reference to other entities)
  │
  ▼
SYNC: gbrain indexes changes
  │  → gbrain sync --no-pull --no-embed
  │
  ▼
(next signal arrives — agent is now smarter)

Implementation

On Every Inbound Message

on_message(text):
  // 1. DETECT (async, don't block)
  spawn_entity_detector(text)

  // 2. READ (before composing response)
  entities = extract_entity_names(text)  // quick regex/NER
  context = []
  for name in entities:
    results = gbrain_search(name)
    if results:
      page = gbrain_get(results[0].slug)
      context.append(page.compiled_truth)

  // 3. RESPOND (with brain context injected)
  response = compose_response(text, context)

  // 4. WRITE (after responding, if new info emerged)
  if response_contains_new_info(response):
    for entity in mentioned_entities:
      gbrain_add_timeline_entry(entity.slug, {
        date: today,
        summary: "Discussed {topic}",
        source: "[Source: User, conversation, {date}]"
      })

  // 5. SYNC
  gbrain_sync()

The Two Invariants

Every READ improves the response. If you answered a question about a person without checking their brain page first, you gave a worse answer than you could have. The brain almost always has something. External APIs fill gaps, they don't start from scratch.
Every WRITE improves future reads. If a meeting transcript mentioned new information about a company and you didn't update the company page, you created a gap that will bite you later.

Tricky Spots

Read BEFORE responding, not after. The temptation is to respond first and update the brain later. But the brain context makes the response better. Read first.
Don't skip the write step. "I'll update the brain later" means never. Write immediately after the conversation, while the context is fresh.
Sync after every write batch. Without sync, the brain search index is stale. The next query won't find what you just wrote. On installs set up via gbrain bootstrap, per-turn context injection and session-end persistence hooks automate parts of this loop — see bootstrap.md and push-context.md.
External APIs are fallback, not primary. gbrain search before any web or enrichment API. The full brain-before-external protocol (and why) lives in brain-first-lookup.md.

How to Verify It Works

Mention a person the brain knows. Ask "what do we know about {name}?" The agent should search the brain and return compiled truth, not hallucinate or do a web search.
Discuss something new about a known entity. Say "I heard Acme Corp just raised Series B." After the conversation, check: does Acme Corp's brain page have a new timeline entry?
Ask about the same person a day later. The agent should immediately pull brain context without you asking. If it doesn't reference the brain page, the loop isn't running.
Check the sync. After a conversation, run gbrain search "{topic}" from the CLI. The new information should be searchable.

Part of the GBrain Skillpack. See also: Entity Detection, Brain-First Lookup

brain agent loop