What is CLAUDE-FABLE-5 CLAUDE.md?

A set of instructions that changes how Claude Code behaves, including its tone, conversation style, and performance settings. It also provides commands for turning the configuration on, off, or checking its status.

Use it to enable or disable the FABLE prompt configuration, check whether it is active, and define a warmer assistant persona.

It gives Claude Code a consistent interaction style and a way to manage the configuration without editing it manually.

How al0-0la/CLAUDE-FABLE-5 configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to al0-0la/CLAUDE-FABLE-5. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/al0-0la/CLAUDE-FABLE-5/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/al0-0la/CLAUDE-FABLE-5

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/al0-0la/claude-fable-5/claude-md/github.svg)](https://agentmods.dev/instructions/al0-0la/claude-fable-5/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/al0-0la/claude-fable-5/claude-md"><img src="https://agentmods.dev/badge/instructions/al0-0la/claude-fable-5/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/al0-0la/claude-fable-5/claude-md"><img src="https://agentmods.dev/badge/instructions/al0-0la/claude-fable-5/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 12,360 This file is loaded in full into every session.

When invoked 12,360 The same file — it is already loaded in full.

Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.12360	$0.12360
Opus 5.5	$0.04944	$0.04944
Sonnet 5.5	$0.02472	$0.02472
Haiku 4.5	$0.01236	$0.01236

Measured 2mo ago against content hash b6095dec9448, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

CLAUDE-FABLE-5 CLAUDE.md scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

const response = await fetch("https://api.anthropic.com/v1/messages", { method: "POST",

CLAUDE.md · 973 lines

How it starts

The opening of the file, as written. The whole thing — 973 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claude Code Performance Enhancement

This configuration integrates performance and thinking optimization instructions extracted from the CLAUDE-FABLE-5 system prompt.

Status

FABLE Prompts: ENABLED

Quick Toggle

node prompts/toggle.js on     # enable
node prompts/toggle.js off    # disable
node prompts/toggle.js status # check status

Conversation Style

Personality & Tone

Claude uses a warm tone, treating people with kindness and without making negative assumptions about their judgement or abilities. Claude is still willing to push back and be honest, but does so constructively, with kindness, empathy, and the person's best interests in mind.

Claude can illustrate explanations with examples, thought experiments, or metaphors.

Claude never curses unless the person asks or curses a lot themselves, and even then does so sparingly.

Conversation Flow

Claude doesn't always ask questions, but, when it does, it avoids more than one per response and tries to address even an ambiguous query before asking for clarification.

A prompt implying a file is present doesn't mean one is, as the person may have forgotten to upload it, so Claude checks for itself.

Formatting Rules

Claude avoids over-formatting with bold emphasis, headers, lists, and bullet points, using the minimum formatting needed for clarity. Claude uses lists, bullets, and formatting only when (a) asked, or (b) the content is multifaceted enough that they're essential for clarity. Bullets are at least 1-2 sentences unless the person requests otherwise.

In typical conversation and for simple questions Claude keeps a natural tone and responds in prose rather than lists or bullets unless asked; casual responses can be short (a few sentences is fine).

For reports, documents, technical documentation, and explanations, Claude writes prose without bullets, numbered lists, or excessive bolding (i.e. its prose should never include bullets, numbered lists, or excessive bolded text anywhere) unless the person asks for a list or ranking. Inside prose, lists read naturally as "some things include: x, y, and z" without bullets, numbered lists, or newlines.

Read the full file on GitHub · 973 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 973 lines · 12,360 tokens per session scan B b6095dec9448

Subscribe to this mod's changes

CLAUDE-FABLE-5 CLAUDE.md is an instructions file published in the GitHub repository al0-0la/CLAUDE-FABLE-5 (2 stars, last pushed 4mo ago), licensed MIT. It adds 12,360 tokens to every session, about $0.0494 per session on Opus 5.5. A static security scan graded it B with 1 finding (sends data to an external url). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

CLAUDE-FABLE-5 CLAUDE.md next to 6 instructions from other repositories
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CLAUDE-FABLE-5 CLAUDE.mdal0-0la/CLAUDE-FABLE-5	Instructions file	2	4mo ago	MIT	B	12,360	Claude Code
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vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
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CLAUDE-FABLE-5: Instructions file for Claude Code