DAYamlChecker

An LSP for Docassemble YAML Interviews

How to run

pip install .
python3 -m dayamlchecker `find . -name "*.yml" -path "*/questions/*" snot -path "*/.venv/*" -not -path "*/build/*"` # i.e. a space separated list of files

MCP / LLM integration

DAYamlChecker includes an optional Model Context Protocol (MCP) server. This allows AI assistants like GitHub Copilot to validate Docassemble YAML directly within your editor.

Quick Start

codex mcp add dayamlchecker -- "~/venv/bin/python" -m dayamlchecker.mcp.server

1. Install with MCP support:

   pip install "dayamlchecker[mcp]"

2. VS Code Automatic Setup: Open this project in VS Code. The included .vscode/mcp.json file will automatically configure the MCP server for you (assuming you have a .venv created).

For detailed instructions on installation, manual configuration, and usage with other clients, please see docs/MCP_SERVER.md.

Generate a VS Code MCP configuration

To make it easy for VS Code users to install locally, install DAYamlChecker with the mcp extra, then run the packaged generator to create .vscode/mcp.json:

# Install in the active environment
pip install "dayamlchecker[mcp]"

# Generate workspace MCP config
dayamlchecker-gen-mcp

Optional flags: --venv <path>, --python <path>, and --non-interactive.

For example, if you have a global venv in ~/venv, and a github repository you want to make the MCP available in named docassemble-AssemblyLine:

cd ~/docassemble-AssemblyLine
source ~/venv/bin/activate
pip install dayamlchecker[mcp]
dayamlchecker-gen-mcp --venv ~/venv

Codex CLI (optional)

If you use Codex CLI/IDE and want Codex to call this MCP server:

cd /path/to/your/repo
codex mcp add dayamlchecker -- "$(pwd)/.venv/bin/python" -m dayamlchecker.mcp.server

# Or add using a global venv
codex mcp add dayamlchecker -- "~/venv/bin/python" -m dayamlchecker.mcp.server

# If the package is installed globally
codex mcp add dayamlchecker -- dayamlchecker-mcp

Important: The codex mcp add command only registers the MCP server configuration in Codex's settings; it does not create virtual environments or install the dayamlchecker package into the target interpreter. Make sure the selected interpreter has dayamlchecker installed before you add the server.

Click-to-install for VS Code

If you want VS Code users to add the MCP server with a single click, include one of the links below. These open VS Code and pre-fill the Add MCP Server dialog. They rely on an interpreter being present at the configured path — the local link expects a repository .venv and the global link expects a global venv such as ~/venv.

Add dayamlchecker (workspace .venv)

Click to add a server that uses a global ~/venv:

Add dayamlchecker (global ~/venv)

Note: Some clients may not expand ~, so replace it with the absolute path if the link doesn't work for you (e.g. /home/yourname/venv/bin/python). Also ensure the package is installed in the selected venv (pip install "dayamlchecker[mcp]"), and the .venv path exists with a Python binary.

Important: The Add links above only register the MCP server configuration in VS Code — they do not install the dayamlchecker Python package or create a virtual environment. Before clicking the link, make sure the runtime is installed in the selected venv. For example:

# create a repo venv and install the package (recommended)
python -m venv .venv
source .venv/bin/activate
pip install "dayamlchecker[mcp]"

# or for a global venv
python -m venv ~/venv
source ~/venv/bin/activate
pip install "dayamlchecker[mcp]"