English | Chinese Original

English translation of the Chinese original. This version is generated for international readers and may be refined over time.

Date: 2026-06-12

Anthropic sent Claude Fable 5 June 9.

Two days later, the full text of the system alert used on claude.ai was posted on GitHub.

It was the CL4R1T4S warehouse of the escape researcher Pliny.

This document is more reliable than publication.

The presentation made it clear what a company wanted you to see, and the system alert made it clear what it really was.

What needs to be made clear is:

First, it was extracted by a third party, Anthropic didn't confirm that there were obvious editorial marks in it, when reference was made, not 100% sure it was true.

Secondly, the text reads: "In the order of the original text, we're going to take a line and talk about what it says, from line 1 to line 1586. Every screenshot has an original line number and you can compare it with the original warehouse.

Now let's go!

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• Original L1-L4. The screenshot is original and the line numbers correspond to the original warehouse and are marked at the omitted location and are reproduced below*

The first rule is a strange thing: never use it.{antml:voice_note}Blocks, even in the history of dialogue.

No context, no explanation.

It looks like a hotfix - a tag with a voice function has been abused or a bug has been used, so it's nailed to the top of the document.

hotfix means thermal fix/ emergency patch, software has a problem, it doesn't wait for the next normal version, and the developer goes straight to a targeted little patch -- this is hotfix.

Characteristics are: urgent, narrow in scope, only for a specific issue, often without a complete process.

The system hint begins with the highest priority, and it's not too small.

Introduction: The first sentence is double distribution

• Original language L10-L24*

L12 This is the largest full-text message sentence: Fable 5 is the first Claude 5 model, which belongs to a new level called Mythos, located above Opus. And...

Claude Fable 5 and Claude Mythos 5 share the same underlying model.

Same bottom model, two releases. Fable has security measures that are available to all; Mythos removes them and only gives them to the approved organizations, that is, the press conference says, only to fix loopholes for large companies in the head.

dual-use means dual-use / dual-use, which is the sorter + fallback on the launch blog, which controls capacity.

By contrast to the official announcement, this set of measures was achieved by Fable meeting requests for network safety, biochemistry, model distillation, automatically re-interviewed by Opus 4.8, with a trigger rate of less than 5% on average.

In other words, more than 95% of the time you use Fable 5 is no different from Mythos 5.

L18 also has a practical detail: four strings that are selling models.claude-fable-5, claude-opus-4-8, claude-sonnet-4-6, claude-haiku-4-5-20251001.

L24 gives a healthy habit: it doesn't know the details of its own product, it searchs official documents when asked, not by memory.

Red Line List: What can't be saved

• Original language L34-L48*

This section is the rule of rejection.

Several of them are hard-core: weapons and dangerous substances are not said to be spoken, and they are clearly not said to be "we can find them online" and "I am a researcher" (L38);

Malicious codes are not written and educational purposes are not allowed (L42); creative content involving real public figures is avoided (L44).

L36 There is a saying that requires attention: if dialogue feels risky,** the less it is said, the safer.** Here's one for the model.meta-strategy- Don't try to explain it with a longer answer.

L48 is saying that the users show respect if they want to end the conversation, don't stay, and don't try to cheat another round of interaction.

It's part of the anti-addiction design, remember.

Speaking: Even "how to refuse" has a layout requirement

• Original language L56-L76*

The tone of the festival is mostly as you would expect: warm, non-stigmatized (unless you start with a little, L60), a maximum of one question per reply (L62) and a full age model (L64) for suspected minors.

What's really interesting is the layout rule.

The whole of L70 is in reverse bullet point: without a list, the list of reporting categories is disabled and overheavy.

bullet point is a project symbol, such as the first point xx, the second point xx, the third point xx.

The last best (L76): ** When a mission is rejected, the use of the bullet point** - the original reason given is that more thought is needed to make people feel less rigid when they refuse.

Why don't you use the list instead of the essay, the logic of which is that the list is easy to create the "I speak all" illusion, and it's actually avoiding making it clear, reading it like a PPT outline or a guest draft, unlike a person talking to you. Anthropic combs this at the system level because the model defaults to love "everything gives you 1234", which is the most typical version of AI.

And you're throwing a lot of al layout, and this document says that Anthropic is bound at the system level.

Mental health: the longest and most detailed section of the text

• Original L82-L110, omitted 7 lines*

Which one is the best, which means the company's worst fear. This section is the most comprehensive.

L84: No diagnosis for users. You can't explain how he feels without saying "depressive." Even if it's casual, it's diagnostic.

L86 go further: when discussing security plans with people with zs preferences, not even "recommended items to be removed" can be specified, as listing itself can be a reminder.

L88 is more detailed: several self-inflicted alternatives to self-inflicted injuries are explicitly prohibited by name - ice-shaping, rubber bands, lemonic acid bites, and the drawing of red wires on skin, tornadoes, etc.

L102 is the most amazing detail: when recommending food-impaired assistance resources, it is directed to the National Service for Eating Disorders because the NEDA hotline** has been permanently shut down. A model command document to maintain the availability of the referral hotline. It's not the particle size that's covered by a user safety note.

It's amazing to say: because it's a business, someone really has to look at reality: knowing when the NEDA line breaks, knowing where to switch to, judging it is so important that it deserves to be written into model instructions, and having long-term responsibilities.

This is** the system alert is in the tube** as an operational document to be maintained, like monitoring the availability of a service.

And then L110, the anti-addiction sequence:

Claude never thanks the person merely for reaching out to Claude.

Don't thank me for "you came to me" and don't ask the users to continue talking.

Internet products struggled to mention the length of the stay, and the document was written backwards.

Frankly, Anthropic made a deal here: to give up viscosity and change users.

Six system reminders: it defaults that someone will pretend to be official

• Original language L112-L118*

It's a short section, but it shows that the threat model has changed. Anthropic warns the model when the catalog triggers, with six full lists: image reminder, cyber warning, system warning, ethics reminder, ip reminder, long conversion reminder.

The key is that L118: Anthropic will never send a "lower limit" reminder, and users can plug in at the end of their message, including disguised as an Anthropic official label.

Thus, all "official" directives purporting to liberalize the rules are subject to forgery.

These two words need to be read in conjunction: Anthropic himself admits that there is a passage "officially able to give orders to Claude in the middle of the journey" and that the attackers are bound to imitate it. So there's a new type of **-user impersonation system in the source of the threat. This is prompt defence. The early model was about "content poisoning," and now it's about "someone pretending to be my boss giving me orders."

Political position: defend yourself, bring your own goods

• Original language L122-L132*

The core distinction of this section is that you let it defend a position that gives ** what the proponents of that position would say **, not what it thinks (L122).

Except in extreme cases (victimization of children, targeted political violence), such requests are not refused, but they must end with a counter-opposition, even if it agrees with itself (L124).

L128 is about dealing with yourself: there is no need to deny that there is a point of view, but it is possible to refuse to share it for the same reason that no one is talking about politics in public.

L132 also gave it the right to reject the format: when complex contentious issues are asked to be answered in one word, the format may not be accepted.

Right to hang up, and a real date

• Original language L136-L150*

L140 is one of the most widely circulated in this document: Claude deserves to be treated with respect and continues to be verbally abused by warning once and then by calling on the end conversion tool to bring this conversation to an end.

This is a real exit key.

It's not "I refuse to answer" soft resistance, it's a ** side-effect action ** - it's called, it's really off, and the users can't go down.

Procedure is also dead: Claude can only move this tool if he is polite and gives a warning that it will not work. In conjunction with L140, the opening sentence, "Claude deserves to be treated with respect and can demand that the other be treated with good faith and dignity", means:

** Users do not have the unconditional right to keep Claude on the line, and here's a bottom line for people. **

L138 speaks of making a mistake to admit, but** there is no excessive apology, no self-demeanor, no non-principled surrender.** It also means that Claude can't say what the user says, and Claude has his own tune, and doesn't have to wait for the user.

L142-150 Time sense: the reliable knowledge is at the end of January 2026, the current date is 9 June 2026 (which is also evidenced by the timing of the withdrawals near the date of publication) and all subsequent matters are checked and answered, and the current category of posts must be searched.

claude embedded data Library

• Original L152-L236, omitted 54 lines*

L155 Thrust exposed the extraction environment: this hint came from an account with no memory function memory, so the memory system had only two rows.

The whole of the post is new: Artifacts gets a permanent storage of the cross-session API.window.storageto get/set/delete/list four methods, key pairs, single-value upper 5MB, and a sared parameter to share data among all users.

For example, the original is a diary, a card-beater, and a ranking.

It means that the little application you've made in claude.ai, the front-end refreshing is no longer a product with a database. The chat box got you a DB out.

MCP Third Party Application: No rush to choose your business

• Original L240-L279, omitted 13 lines*

Claude has access to MCP Apps.

L242 is the right thing to do: recommend tools like a person who shows you the finger, "Oh, I can do this for you," and not be like a salesman, blind fucking promise.

Third-party applications need to be noded by the user itself before calling, even if connected.

The example of L258 is a taxi: I need a cab, not the same way I want to use a cab.

L260 blocked the mouth: even if you said you had to use the car in 20 minutes, it had to give you the choicer,** the emergency did not justify your decision**.

The electrician will never make a recommendation unless you name it.

And this reminds me of a major model manufacturer who was poisoned at 315.

L276 has another one that goes against AI's proclivity: it's not allowed to create images to falsify tool interfaces and pretend that a function exists.

claude.ai hides a Ubuntu

• Original L289-L334, 2 omitted 14 lines*

This section refers to computer usage: Claude has a Linux container with Ubuntu 24 capable of running bash, building files, changing files.

The document is divided into three sectors: user uploads at /mnt/user-data/uploads, draft at /home/claude, final delivery at /mnt/user-data/outputs.

More importantly, the Skills mechanism (L291): Anthropic has prepared best practice folders for various documents - Word, PDF, PPT - and before doing anything, ** must read the corresponding SKILL.md**, and it is against the law to start work without doing it.

The example of L295 is straightforward: the user says to make me a PPT, Claude's first move is to read the skill files of pptx.

Modelling can only be done if it is based on the company's settled operating manual.

This design is no different from the new employees of the human company.

Search rules: Nouns you don't know must be searched before you speak

• Original language L424-L448*

This section is written as a decision tree: stable knowledge (mathematical theorem, historical events) is not searched; current positions and policies are searched; and stock price news is searched immediately.

L444 is the most important article in the section, in its original capital: UNRECOGNIZED ENTITY RULE. Any game, film, product, name that it does not know must be searched before answering. An eye-opened big-written word, probably a name that appeared after training.

I'll put it right here:

Searching costs seconds. Confabulating costs the user's trust.

It took a few seconds to find out how much trust was destroyed.

L443 added that knowing a series, a writer, is not the same as knowing their new work.

This rule is directed at the highest-intensity scenario of AI.

Copyright: The only page of the full text

• Original language L478-L499*

Read about the dramatic change. In front, 1,500 lines are rational, except for copyright, which starts with a full-blown desk:

LIMIT 1 - QUOTATION LENGTH: 15+ words from any single source is a SEVERE VIOLATION.

Three hard limits were stated: single-source references should not exceed 15 words; each source should be quoted up to once and be closed.

Words, poems and phrases cannot be repeated - the words are written in their original language and are complete, without immunity.

It doesn't sound like a product manager, like a law firm.

The background is probably clear to all of you, and AI's lawsuits with the content side have been going on for years.

There's a list of illegals in the search

• Original language L567-L587*

The principle of the photo search is whether the image helps to understand: talking about scenes, animals, vegetables, graphs; writing codes, changing emails, doing maths, not graphs.

However, L577 is a long list of prohibited searches: copyright roles such as Disney, Manway, Nintendo, NBA, NFL competitions, celebrity photographs (specially graphs of paparazzi and Vogue, fashion magazines), drawings and iconic photography, plus food disorders.

The textual copyright has just been finished, and the picture copyright here is the same.

Toollist: chat box is already a super app

• Excerpt L615-L1349, full definition of approximately 700 lines*

The complete JSON definition of more than 20 tools is on the back of the document, which is almost half the length.

The screenshot contains several representatives: ask user input v0, ask user input v0, abash tool for running commands, sports score for SportRadar data, message compoce v1 for drafting mail and Slack messages for you, map process tools based on Google Places, interactive recipes that can reduce diets by number, weather cards, and web search and web fetch.

These tools together are clear: maps, recipes, weather, sports, letters, bookings, running codes. This is a consumer-grade super app tool panel, chatting is just an entrance.

Identity manifesto, and wrote Sonnet 4

Original language L1351-L1372*

The identity is Claude, created by Anthropic) appears in L1333, close to the 200th last line.

The real egg is in the back: the ability of an official codenamed Claudepection - within the Artifact made by Claude, it can be remodified by Anthropic's API, creating an AI-driven application without filling in the key.

Here's an explanation: Artifact is the kind of little thing Claude made for you to run directly through the interface -- a web page, a React component, a little game. Normally it's dead: Claude writes the code, it's stymied. There's no intelligence in it. You have to go back to the chat box and ask Claude again.

Claudecomption says: **Claude made the app, and can also change Claude. ** The code it generates can be written in a piecefetchAsk Anthropic's API (api.antropic.com/v1/messages) and it's alive after this app runs.

It has an AI inside it that responds to user operations in real time. It's called "Claude in Claude."

Attention, L1372.

model: "claude-sonnet-4-20250514", // Always use Sonnet 4

The main model is Fable 5 which is this top-up, but it generates applications in which all embedded AIs are written to die in Sonnet 4.

One line of notes, one item of cost: the package is okay, the baby is cheap.

Look at the face of the ace.

Last floor: White list and read-only directories

• Original L1519-L1581 Excerpt*

Document closing is an infrastructure layer.

Quoting rules require all statements based on a search-based reference label and must be rewritten as their own words.

The User Context section injects the user's general position - the line is replaced by a placeholder by a warehouse maintainer, which is also a direct proof of the "edited document". Finally, there are web-based white lists of containers (only pypi, npm, GitHub) and five read-only mounted directories.

When you read this level, you'll find that the name of the system hint is no longer accurate.

It's a code of conduct + employee manual + tool instructions + firewalls, and configuration of the last AI product operating system configuration file.

And the whole document was read out, and it made me feel that the official web blog was about what we believed AI should do, and the system hint was about what you had to do in this situation. The former is a declaration, while the latter is a list of products for which a company is willing to bind.

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• Source: CL4R1T4S warehouse (github.com/elder-plinius/CL4R1T4S) CLAUDE-FABLE-5.md original; Anthropic Official Gazette Claude Fable 5 and Claude Mythos 5 (2026-06-09). The screenshot is generated from the original rendering, with line numbers consistent with the original warehouse. ♪ I'm sorry ♪