md-mcp

An MCP server that gives agents surgical read/write access to individual sections of Markdown files.

Overview

Large Markdown files — documentation, changelogs, wikis — are expensive for agents to work with: reading the entire file just to update one section wastes tokens, and rewriting the whole file risks accidental data loss. md-mcp solves this by exposing each section as an individually addressable unit, so an agent can fetch, edit, or delete exactly the slice it needs without touching anything else.

The server runs over stdio as a local MCP server. Files are addressed by path on disk; sections within a file are addressed by a dot-separated heading path (e.g. "User Guide.Installation.Prerequisites"). Parsed ASTs are cached in memory and invalidated automatically on mtime change, so repeated reads of an unchanged file are fast.

Installation

The package is not yet published to PyPI. Install it in editable mode directly from the repository.

pip

pip install -e .

uv

uv pip install -e .

Connecting to opencode / Claude Desktop

After installation the md-mcp entry-point script is on your PATH. Add it as a local stdio MCP server in your client config.

opencode (opencode.json / opencode.jsonc)

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "md-mcp": {
      "type": "local",
      "command": ["md-mcp", "--allow-root", "/your/docs/dir"]
    }
  }
}

Claude Desktop (claude_desktop_config.json)

Claude Desktop uses the top-level key mcpServers:

{
  "mcpServers": {
    "md-mcp": {
      "command": "md-mcp",
      "args": [],
      "transport": "stdio"
    }
  }
}

Dot-path addressing

Every tool that targets a section takes a path argument — a dot-separated string of heading texts from the document root down to the target section. Given this Markdown file:

# My Project

## Installation

### Prerequisites

## Usage

The available paths are:

Section	Path
# My Project	My Project
## Installation	My Project.Installation
### Prerequisites	My Project.Installation.Prerequisites
## Usage	My Project.Usage

Matching is case-insensitive, so my project.installation and My Project.Installation resolve to the same section. Ambiguous paths (duplicate heading texts at the same level) resolve to the first match.

Tool reference

Tool	Arguments	Returns	Description
get_index	file_path: str	dict	Returns the full section tree of a file as a nested dict with heading, level, path, and children fields.
get_section	file_path: str, path: str, depth: int | None = None	str	Returns the raw Markdown text of the named section. depth=None (default): full subtree; depth=0: heading + own body only; depth=N: heading + N levels of children.
search_sections	file_path: str, query: str, case_sensitive: bool = False	list	Searches all section bodies for lines matching query (Python regex). Returns a list of {"path", "matches": [{"line", "text"}]} objects in file order. Each section's own body is searched independently — results are never duplicated across parent and child. Heading text is not searched — use get_index to find terms in headings.
add_section	file_path: str, heading: str, content: str, under: str | None = None, before: str | None = None, after: str | None = None	str	Inserts a new section. heading must start with #–###### followed by a space. Placement: under (last child), before (immediately before), after (immediately after including its children), or omit all to append. Returns "ok".
replace_section	file_path: str, path: str, new_content: str	str	Replaces the body of the named section, preserving its heading line. Returns "ok".
patch_section	file_path: str, path: str, new_content: str	str	Returns a unified diff of what replace_section would write, without modifying the file. Returns an empty string if there are no changes.
delete_section	file_path: str, path: str, include_children: bool = True	str	Deletes the named section. With include_children=True (default) removes the heading, its body, and all child sections; with False removes only the heading and its direct body, promoting children. Returns "ok".

Examples

A short worked session against a file docs/guide.md whose top-level heading is User Guide:

1. Inspect the structure

get_index("docs/guide.md")

Returns a nested tree:

{
  "sections": [
    {
      "heading": "User Guide",
      "level": 1,
      "path": "User Guide",
      "children": [
        {
          "heading": "Getting Started",
          "level": 2,
          "path": "User Guide.Getting Started",
          "children": []
        },
        {
          "heading": "Configuration",
          "level": 2,
          "path": "User Guide.Configuration",
          "children": []
        }
      ]
    }
  ]
}

2. Read a section

get_section("docs/guide.md", "User Guide.Getting Started")

Returns the raw Markdown text of that section (heading line + body).

3. Preview a change

patch_section("docs/guide.md", "User Guide.Configuration", "Set `debug: true` in `config.yaml`.")

Returns a unified diff showing exactly what would change — nothing is written yet.

4. Apply the change

replace_section("docs/guide.md", "User Guide.Configuration", "Set `debug: true` in `config.yaml`.")

Returns "ok". The file is updated; the heading line is preserved unchanged.

5. Add a new section

add_section("docs/guide.md", "## Troubleshooting", "See the FAQ.", after="User Guide.Configuration")

Returns "ok". The new ## Troubleshooting section is inserted immediately after ## Configuration.

6. Find sections mentioning a term

search_sections("docs/guide.md", "debug")

Returns:

[
  {
    "path": "User Guide.Configuration",
    "matches": [
      {"line": 18, "text": "Set `debug: true` in `config.yaml`."}
    ]
  }
]

Development

Requirements: Python 3.11+

Install the package with dev dependencies:

pip install -e ".[dev]"

Run the test suite:

pytest

Set up and run pre-commit hooks (ruff + mypy):

pre-commit install
pre-commit run --all-files