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gbrain-lite

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Lightweight personal knowledge base — markdown + YAML frontmatter structured notes with full-text search and cross-referencing for AI agents

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  2. Copy the prompt below and paste it into your agent.
  3. Review the proposed files and risks before you approve installation.
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I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/cosmicstack-labs/mercury-agent-skills/blob/HEAD/categories/ai-ml/gbrain-lite/SKILL.md

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Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

GBrain Lite — Lightweight Personal Knowledge Base

Organize books, people, concepts, and news items from conversations into a searchable, cross-referenced markdown knowledge base.

Workspace

  • Knowledge base directory: brain/
  • Subdirectories by type: books/ people/ meetings/ ideas/ articles/ projects/ news/
  • One entry = one .md file
  • News entries by date: news/YYYY-MM-DD/

Workflow

  1. Trigger check — Book/person/concept/news mentioned in conversation → proactively check brain
  2. Search — Full-text search in brain/ directory (ripgrep/grep)
  3. Decide
    • Existing entry → reference it, update if needed
    • No entry + important → create immediately
    • No entry + uncertain → ask user
  4. Create — Write brain/{type}/{slug}.md
    • Slug: lowercase/hyphenated
    • Must include YAML frontmatter (title, type, date, tags, summary)
  5. Cross-reference — Update links field in related entries
  6. Sync — Keep key entry index in agent memory

Rules

  • Don't dump long content directly into agent memory — prefer brain
  • Don't create entries without title and date
  • Don't skip the summary field — search and listing depend on it
  • Don't manually write updated — it auto-updates on save
  • News entries must use item_id as dedup key (format: github:owner/repo / hn:12345 / arxiv:url)
  • Don't do full overwrite updates on existing entries — use targeted patches

Validation

  • New entry has complete frontmatter (title, type, date, tags, summary)
  • Full-text search finds the new entry
  • News entries contain item_id + first_seen + star_history (GitHub entries)
  • Agent memory usage below 90%, otherwise trigger distillation to brain

Pitfalls

Brain vs Memory confusion

  • Symptom: Long-form content consumed all agent memory space
  • Root cause: Everything dumped into memory instead of brain
  • Fix: >500 chars → brain entry; memory only keeps index pointers. (Fixed: 2026-05-12)

Missing item_id on news entries

  • Symptom: Duplicate news entries accumulate, dedup impossible
  • Root cause: Agent skipped item_id field when creating news entries
  • Fix: Always include item_id for news entries, validated in creation workflow

References

  • references/garry-tan-gbrain-inspiration.md — GBrain system design reference