Short answer: Keep hub.md and add a short AGENTS.md beside it that tells the assistant to read the hub first. Claude Code and Codex both read AGENTS.md, so one pointer serves both. The hub is information about the problem; an instruction file is directions for the assistant. Mixing them causes three problems.
How it works
- The assistant treats instruction files as instructions. A brief full of customer quotes and open questions can read like commands. A pointer file keeps the instructions few and the evidence separate.
- Hubs outgrow instruction-file budgets. Instruction files load on every task, and Anthropic recommends keeping each one under 200 lines. Codex stops loading instruction files after 32 KiB combined by default, so a long hub can crowd out the wiki-wide rules.
- The hub should outlive any one tool. Keeping the facts in hub.md, with AGENTS.md as a thin pointer, lets any assistant, script, or person read the same brief.
File: opportunities/pricing-page/AGENTS.md
- Read hub.md before any task here.
- Rebuild spokes/ from hub.md.
- Never edit a spoke to disagree.
- Append to decisions.md, sources/.
- Never rewrite earlier entries.
To load the hub automatically in Claude Code, write @hub.md in that AGENTS.md. Claude Code expands the import whenever it loads the file, so the hub uses context on every task in that folder; keep it short. Check the Codex docs before relying on imports there.