MCP server · Coding

Fable Mode MCP server

Makes your AI coding agent slow down, show proof, and get reviewed before it edits your files.

Fable Mode is a helper that sits between your AI coding agent and your project files. It keeps the agent from writing code until it has spent a set amount of time thinking, shown real proof for its claims, and survived a round of criticism. It is handy if you have ever watched an AI assistant rewrite half your project in ten seconds and then break everything.

What is an MCP server? The 30-second version

On its own, your AI can only chat with you. An MCP server is a small helper program that gives your AI a new skill or a connection, and here it connects your AI to Fable Mode. Once connected, your AI can ask Fable Mode to open a session, record evidence, and request permission to write. Fable Mode answers back with rules and status, so your AI has to follow a process instead of just typing code.

What this MCP server does

You ask your AI to work on a coding task and give it a time budget. The AI opens a Fable Mode session, and the workspace starts locked. The AI has to spend the thinking time, write down evidence for what it claims, and pass a red-team review before it can ask to unlock writing. Only when those steps are done does Fable Mode let the AI touch your files. Along the way you can check the status to see the current phase, the time left, and how much evidence has been collected.

Flow diagram: you ask your AI “Refactor the parser, keep the same behavior”, on your own computer the Fable Mode MCP server works with your own computer, and you get back proof before any file changes.

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What you can do with it

Open a locked coding session with a goal and a time budget
Force your AI to wait before it is allowed to write code
Collect evidence receipts for claims the AI makes
Run a red-team review that tries to break the proposed code
Unlock writing only after the timer and proof checks pass
Check the current phase, remaining time, and lock state at any moment
Keep a sealed record of what was verified in the session

Try asking your AI

“Use Fable Mode to refactor the parser without changing public behavior, with a two minute budget”
“Start a Fable Mode session called demo-refactor and show me the status”
“Ask Fable Mode for permission to write, and tell me why it is still locked”
“Run the red-team review on this change and show me what it found”

What it gives back to you

You get short status answers in the chat: the current phase, how much time is left on the timer, how many pieces of evidence have been recorded, and whether writing is still locked. When the AI asks to unlock and the checks fail, you see the reason it was rejected. When everything passes, you get a confirmation that the workspace is open, plus a record of what was verified.

Before you start

What you need

Python 3.10 or newer
uv (the tool that runs uvx commands) if you use the uvx install path
An MCP-capable coding agent such as Claude Code or Cursor, or a shell sandbox if you use the direct JSON path

Good to know

This controls when your AI is allowed to write to your project, so if you unlock or bypass it you lose the protection it was giving you.

Install it with your AI

Add Fable Mode MCP server to your AI, no technical skills needed

You don't install anything by hand. You copy one prompt, paste it into an AI that can work on your computer, and it checks, installs and connects the server for you, asking you when it needs something.

Sign in to get the install prompt

Members get a ready-made prompt that lets the Claude desktop app check Fable Mode MCP server, install it and connect it for them, step by step. You don't need any technical skills: you copy, paste and answer a few questions. Your connected AI can also find and install any of the 4,066 MCP servers here for you.