About Folio
Folio serves a live browser view of a folder of Markdown and data files, with tools for understanding the folder as a whole. It is for people and agents working with document collections, combining change tracking, data views and consistency checks while keeping files as plain Markdown.
Key features
- 01Render Markdown with math, code and diagrams
- 02Track changes by page block
- 03View CSV, JSON, Parquet and SQLite data
- 04Embed live tables, charts and SQL results
- 05Check figures against source data
- 06Find broken links and rule failures
Use cases
- 01Review changes to notes since the last visit
- 02Explore data files and filter their records
- 03Keep figures in documents aligned with data
- 04Check folder links and conventions in CI
MCP support
Folio provides an MCP server that gives agents access to the same folder model shown in its browser view. Its agent skill also guides agents in writing documents that use that model.
Configuration
Local server config is the same for every client. Copy it into your client’s MCP config file.
Tools
16Saved tool list · updated 4d ago
| Parameter | Type | Required | Description |
|---|---|---|---|
| folder | string | No | A folder, relative to the served folder or absolute under it, such as notes/; omit for the whole folder |
Details
From the project READMEFolio
A live view of a folder of markdown and data. Point Folio at a folder and read it in your browser: every page rendered with GitHub-flavoured markdown, math, highlighted code and diagrams, every page current the moment you save it, and the folder known as a whole - what you have not read yet, which figures no longer match their data, what links where and what is broken.
Install and run
npx @jakubro/folio ~/notes
Open the address it prints: http://localhost:8640/, or the next free port when that one is taken. Folio needs Node.js 22.18 or later; npm install --global @jakubro/folio keeps it installed as folio.
In Claude Code, two commands install Folio's MCP server and its agent skill as a plugin:
claude plugin marketplace add jakubro/folio
claude plugin install folio@folio
The plugin's tools read the Folio serving the folder Claude Code is opened in; its Folio setting, in /config, names another by its address, such as localhost:8641, or its socket.
What Folio does
Folio keeps a model of the whole folder:
- What is new to you. Folio remembers what you have read. Reopen a page and every block added, changed or removed since is marked - a table by its rows, a list by its items, code by its lines - the old wording a click away, and the tree points at every document that moved.
- Data files and data in documents. CSV, JSON, Parquet, SQLite and other data files open as tables and trees, with each column's spread under its header and, for any filter, what sets its records apart from the rest. A document embeds a table, a chart or a single value from them, or a SQL query across them, and each one redraws when its data changes.
- Tables that sort and filter. Tables written in a page, embedded from data or opened from a data file sort by several columns and filter by text, whole values, patterns or several values at once, the filters joined by and or or. None of it touches the file, and the view lives in the page's address.
- Figures checked against their data. Tie a number in your prose to the data it quotes, and Folio flags it the moment the data disagrees.
- Folder conventions and health. Declare kinds of documents and rules as queries in a
FOLIO.md. One health view - andfolio checkin CI - lists every broken link, missing include, failing query and broken rule. - History. Every version git holds, merged with the saves Folio saw, compared block by block, and digests of any day or week.
- Agents and editors. An MCP server, a JSON API and a language server give them the same model you read, and an agent skill teaches agents to write documents that use it.
The folder stays plain markdown: every page still reads on GitHub, and Folio writes into it only what a FOLIO.md asks for.
Documentation
Full documentation is published at jakubro.github.io/folio.
- Guide - every view Folio adds, with pictures
- Reference - every option, address, key and rule, and what Folio reads and writes
- Architecture - how Folio works inside, and why
License
Copyright (C) 2026 Jakub Roman. Distributed under the GNU GPL v3.
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.