Recipes / Personal ops
Multi-agentSkillPersonal ops

Tell Claude and Codex how to use your second brain

Standing custom instructions that force agents to read your company and personal brains before every task, flag conflicts, and propose exact edits only after you approve.

From Corey Ganim on X · Oct 2026

Setup time10 min
CostIncluded in plan
RunsOnce, then every task
NeedsClaude Code or Codex, company + personal notes
Last updated2026-10-17

What the source did

  • Wrote custom instructions that apply on every task for Claude/Codex.
  • Agents must read a company brain and a personal brain before acting, flag conflicts with quotes, and ask which version wins.
  • Brain edits are proposed as exact diffs and applied only after approval (for GitHub, as a PR).
“If you built a second brain but haven't told Claude/Codex how to use it, it's useless.”— Corey Ganim (@coreyganim), X

Summary written by Agent Cookbook. See the original for the full context.

Their prompt

From Corey Ganim Their exact wording (his generalized version). Source ↗

These apply to every task in every project. A project's own instructions file (AGENTS.md, CLAUDE.md, a project README) can add rules, but the conflict rule and the response rules below always apply.

Approval rule

🛡
Never edit either brain until you approve the exact change. Sending, buying, posting, and deleting always need a human.

Set it up

  1. Fill the table with your real brain names and locations.
  2. Paste into Claude Code custom instructions / CLAUDE.md and Codex AGENTS.md (or project instructions).
  3. Run one real task and confirm it reads the brains and stops on a deliberate conflict.

Common failures

⚠
  • Agent invents brain content when the connector fails; keep the "tell me in one line" rule.
  • Edits land without approval if you soften step 3; keep the exact-edit-then-wait rule.

Variations

  • One brain only if you are solo.
  • Add a third "clients" brain with the same conflict rule.

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