Qt Documentation MCP Server

mcp-name: io.github.jztan/qt4-doc-mcp-server

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Bring locally installed Qt 4.8, Qt 5, or Qt 6 documentation to your AI coding assistant. Works offline with one selected documentation set at a time.

Tool Reference | Changelog | Contributing | Troubleshooting

✨ Features

• 🔌 Offline-First - Works entirely with local documentation
• 🔍 Full-Text Search - Find what you need across all Qt docs
• ⚡ Smart Caching - Fast responses for repeated queries
• 🎯 Fragment Support - Extract specific sections when needed
• 🛠️ MCP Standard - Compatible with Claude, VS Code, and other MCP clients

📦 Prerequisites

• Python 3.11+ required (not needed when using the Docker image)
• Qt HTML Documentation for one supported release (Qt 4.8, Qt 5, or Qt 6)
  • The included helper downloads Qt 4.8.4 only.
  • Point QT_DOC_BASE directly at an existing Qt 5/6 offline documentation root.
• ~500MB disk space for docs + cache + search index
• SQLite with FTS5 support (included in Python 3.11+ by default)

🚀 Installation

From PyPI (Recommended)

pip install qt4-doc-mcp-server

From Source

git clone https://github.com/jztan/qt4-doc-mcp-server.git
cd qt4-doc-mcp-server
uv sync --locked

Setup Qt Documentation

# Automated setup (recommended, requires the cloned repo)
python scripts/prepare_qt48_docs.py --segments 4

# This will:
# - Download Qt 4.8.4 source archive
# - Extract HTML documentation
# - Create .env with sensible defaults
# - Copy GFDL license file

The helper script ships with the repo, not the PyPI package. Installed from PyPI only? Download the docs manually instead:

curl -LO https://download.qt.io/archive/qt/4.8/4.8.4/qt-everywhere-opensource-src-4.8.4.tar.gz
tar -xzf qt-everywhere-opensource-src-4.8.4.tar.gz qt-everywhere-opensource-src-4.8.4/doc/html
mv qt-everywhere-opensource-src-4.8.4/doc/html ./qt4-docs-html

Then create a .env with QT_DOC_BASE pointing at that directory (see Configuration below).

Quick Start Commands

# 1. Install
pip install qt4-doc-mcp-server

# 2. Setup Qt docs
python scripts/prepare_qt48_docs.py --segments 4

# 3. Build search index (optional; the server builds it on first start)
qt-doc-build-index

# 4. Start server
qt-doc-mcp

# 5. Verify health
curl -s http://127.0.0.1:8000/health

The legacy qt4-doc-mcp-server command remains available as an alias for existing client configurations.

Agent-friendly FTS CLI

After building the index, agents can search and receive materialized absolute Markdown paths:

qt-doc-cli "accessible applications" --limit 5

The command reads the same .env settings as the server. Before searching, it automatically builds a missing/outdated FTS index and fully warms an incomplete Markdown cache. It then prints each result's title, absolute .md path, and FTS snippet to stdout; preparation messages, errors, and warnings go to stderr. Use qt-doc-warm-md --force after changing documentation in place.

🐳 Docker

Prebuilt multi-arch images (amd64/arm64) are published to GitHub Container Registry on every release. The container is offline-only: you mount your prepared Qt doc/html directory read-only at /docs, and all derived state (Markdown cache and search index) lives in a volume at /data.

# Prepare Qt docs on the host first (one-time, writes to ./qt4-docs-html)
python scripts/prepare_qt48_docs.py --segments 4

# Run from GHCR
docker run -d --name qt4-doc-mcp-server -p 8000:8000 \
  -v "$PWD/qt4-docs-html:/docs:ro" \
  -v qt4-doc-data:/data \
  ghcr.io/jztan/qt4-doc-mcp-server:latest

# Verify
curl -s http://127.0.0.1:8000/health

Using only the published image, without cloning this repo? Download the Qt 4.8.4 docs directly instead of running the prepare script:

curl -LO https://download.qt.io/archive/qt/4.8/4.8.4/qt-everywhere-opensource-src-4.8.4.tar.gz
tar -xzf qt-everywhere-opensource-src-4.8.4.tar.gz qt-everywhere-opensource-src-4.8.4/doc/html
mv qt-everywhere-opensource-src-4.8.4/doc/html ./qt4-docs-html

Any existing Qt 5 or Qt 6 doc/html tree (from the Qt installer or distro documentation packages) works as the mount source too.

First start converts and indexes the documentation into the /data volume; subsequent starts reuse it. Depending on the docset size, the first start can take a minute or two before the health endpoint responds.

Docker Compose

With docs in the default ./qt4-docs-html location, no configuration is needed:

docker compose up -d

For docs elsewhere (including Qt 5 or Qt 6 doc/html trees, which the server also supports), point QT_DOC_HTML_PATH at them. If port 8000 is taken on the host, set HOST_PORT in the same file (with plain docker run, change the left side of -p instead):

cp .env.docker.example .env.docker   # set QT_DOC_HTML_PATH
docker compose --env-file .env.docker up -d

Or use the convenience script, which checks Docker is running, creates .env.docker on first run, builds and starts the service, and waits for the health endpoint:

./deploy.sh

Point your MCP client at http://127.0.0.1:8000/mcp (streamable HTTP). Qt documentation is licensed under GFDL 1.3; the container serves your local copy and never redistributes it.

⚙️ Configuration

These settings apply to native (pip or source) runs. In Docker they are already set inside the container (QT_DOC_BASE=/docs, QT_DOC_STATE_DIR=/data, SERVER_HOST=0.0.0.0); the QT_DOC_HTML_PATH variable in .env.docker is not a server setting, just the host path mounted at /docs.

Create a .env file in the repo root. The helper script writes sensible defaults; adjust as needed:

The tools identify documents by their exact root-relative Markdown path, not an online URL. For example, use qcompleter.md for a Qt 4 page, qtdoc/accessible.md for a Qt 5/6 global page, or qtcore/qobject.md for a Qt 5/6 Core page. By default, each docset stores its own index and Markdown cache under $QT_DOC_BASE/.index/, so switching QT_DOC_BASE reuses its existing derived state. Set QT_DOC_STATE_DIR to relocate both to a writable directory. The Markdown cache mirrors the documentation tree: for example, qtcore/qobject.md is cached as .index/md/qtcore/qobject.md plus qobject.meta.json with the default state directory.

🔌 MCP Client Setup

By default, the server exposes an HTTP endpoint at http://127.0.0.1:8000/mcp. Register it with your preferred MCP-compatible agent using the instructions below.

Stdio transport

Run the server over stdio instead of HTTP with:

qt-doc-mcp --transport stdio

For stdio-only MCP clients, configure that command with args: ["--transport", "stdio"]. Startup indexing and Markdown-cache progress are written to stderr, leaving stdout exclusively for MCP protocol messages.

code --add-mcp '{"name":"qt-docs","type":"http","url":"http://127.0.0.1:8000/mcp"}'

{
  "servers": {
    "qt-docs": {
      "type": "http",
      "url": "http://127.0.0.1:8000/mcp"
    }
  }
}

claude mcp add --transport http qt-docs http://127.0.0.1:8000/mcp

{
  "mcpServers": {
    "qt-docs": {
      "type": "http",
      "url": "http://127.0.0.1:8000/mcp"
    }
  }
}

codex mcp add qt-docs -- npx -y mcp-client-http http://127.0.0.1:8000/mcp

[mcp_servers.qt-docs]
command = "npx"
args = ["-y", "mcp-client-http", "http://127.0.0.1:8000/mcp"]

{
  "mcpServers": {
    "qt-docs": {
      "type": "http",
      "url": "http://127.0.0.1:8000/mcp"
    }
  }
}

{
  "mcpServers": {
    "qt-docs": {
      "command": "npx",
      "args": ["-y", "mcp-client-http", "http://127.0.0.1:8000/mcp"]
    }
  }
}

🛠️ Available Tools

The server provides 2 MCP tools for working with the active local Qt documentation set:

1. read_documentation - Read and convert pages from the active Qt documentation set to Markdown

   • Fragment extraction (#details, #public-functions)
   • Pagination with start_index and max_length
   • Section-only mode for targeted content
   • Returns Markdown with normalized links and GFDL attribution

2. search_documentation - Full-text search across the active Qt documentation set

   • SQLite FTS5 with BM25 relevance ranking
   • Context snippets with highlighted matches
   • Configurable result limits (default: 10, max: 50)

For detailed API documentation including parameters, return values, examples, and error handling, see the Tool Reference.

📚 Related Resources

• Model Context Protocol Specification
• Qt Documentation
• FastMCP Framework
• Tool Reference
• Changelog
• Contributing Guide
• Troubleshooting Guide

📄 License

• Code: MIT License (see LICENSE).
• Qt Documentation: © The Qt Company Ltd. and contributors, licensed under GFDL 1.3. This server converts locally obtained docs and includes attribution in outputs. If you redistribute a local mirror, include LICENSE.FDL and preserve notices.
• See THIRD_PARTY_NOTICES.md for more details.