FABLE.md

A single-file operating standard for Claude Code — and most other coding agents.

FABLE.md does not make the model smarter. Capabilities live in the weights, not in prompts (that's literally section 0 of the file). What it does is encode the working discipline that separates excellent output from mediocre output on the same model:

• Honesty & pushback — "it should work" is banned: tested, or declared untested. Disagreeing with a flawed request before executing is mandatory.
• Anti-hallucination — every API/flag/version verified before it lands in delivered code; every number needs a traceable origin.
• Calibrated autonomy — a hard list of actions that always require asking first: spending money, deploys, deletions, irreversible operations, scope changes.
• Reasoning discipline — plans proportional to task size, treated as contracts; edge cases considered by default; alternatives noted for structural decisions.
• Project memory — STATUS.md updated at session end, so the next session restarts from a file, not from vibes.
• Plus: code quality rules, source hierarchy for research, communication format, and an end-of-work self-check.

How to use it

1. Drop FABLE.md into your project root.

2. Reference it from your project's CLAUDE.md:

   Read FABLE.md in full at the start of every session and treat its rules
   as hard constraints.
   

   Or paste its content directly into CLAUDE.md / AGENTS.md if you prefer a single file — the content is tool-agnostic apart from a few Claude Code conventions.

3. Customize the USER PROFILE block in section 1 (name, experience, stack, communication language). This is what lets the model calibrate depth and pushback to you.

4. Priority on conflict: model safety policies > FABLE.md > project CLAUDE.md > model defaults.

What it is not

• Not a jailbreak, not a "model upgrade", not magic. If a rules file promises to turn one model into a better one, it's lying to you.
• Not a new idea. Instruction files for coding agents are an established practice (CLAUDE.md, the open AGENTS.md standard). FABLE.md is a distilled, opinionated version focused on working discipline rather than project context — the two complement each other.
• Not affiliated with Anthropic. Claude is Anthropic's product; the name FABLE is a nod to their model naming. This is an independent, unofficial project.

Files

File	Description
FABLE.md	English version
FABLE.it.md	Italian version (the original)

Origin

Distilled from months of daily production use of Claude Code across web agency, hosting and product development work. First shared on r/ClaudeAI.

Contributing

It's a v1.0. If a rule doesn't work in practice, is missing, or conflicts with how a specific model behaves, open an issue or a PR.

License

MIT — see LICENSE.

Maintained by ReviewMost4463 — GitHub.