ReqCheck MCP server

Finds ambiguous terms in a requirements document, checked against ISO/IEC/IEEE 29148:2018, and hands the client the question templates needed to ask the author what they actually meant.

Detection is deterministic — regex over a versioned rule catalog, no model involved — so the same text always produces the same findings, and every finding cites the clause it came from.

Part of ReqCheck, which also ships a web app for the same checks.

What it exposes

Kind	Name	Purpose
Tool	ambiguity_analysis(text)	Every flagged term with its statement, severity, explanation, ISO citation, and question templates
Resource	reqcheck://knowledge-base	The full rule catalog as authored, with citations
Prompt	check_requirements(text)	Analyses a document and reports findings in a fixed format

Install from PyPI

1. Install uv (skip if you already have it): This command is for macOS/linus

curl -LsSf https://astral.sh/uv/install.sh | sh

Claude Code:

claude mcp add reqcheck -- uvx mcp-reqcheck

This command is for installing mcp in the directory you are cd into only.

To install this MCP for all directories, use claude mcp add reqcheck --scope user -- uvx mcp-reqcheck

Claude Desktop — add to ~/Library/Application Support/Claude/claude_desktop_config.json:

  "mcpServers": {
    "ReqCheck": { "command": "uvx", "args": ["mcp-reqcheck"] }
  },

Then restart Desktop.

Install from source

1. Install uv (skip if you already have it):

curl -LsSf https://astral.sh/uv/install.sh | sh

2. Get the code:

git clone https://github.com/hjchen114514/ReqCheck.git
cd ReqCheck/apps/mcp_reqCheck

3a. Claude Desktop:

uv run mcp install src/mcp_reqcheck/server.py --with PyYAML

Restart Desktop. ReqCheck should show green under Settings → Developer.

3b. Claude Code — needs the absolute path. Print it from this folder:

pwd
# /Users/you/ReqCheck/apps/mcp_reqCheck

claude mcp add reqcheck -- uv run --with "mcp[cli]" --with PyYAML mcp run <paste-path>/src/mcp_reqcheck/server.py

Check it with claude mcp list.

--with PyYAML is required when running from source. The client launches the server from its own working directory, so uv never reads this project's pyproject.toml and builds an environment from the --with flags alone. Without it the catalog loader fails on import yaml and the client reports "Server disconnected". Installed users don't need it — uvx resolves declared dependencies.

Use it

Ask your client something like:

Check these requirements for ambiguity: The system shall be user-friendly and load significantly faster than the old site.

It calls ambiguity_analysis, gets back the flagged terms with their reasons and citations, and asks you follow-up questions rather than rewriting your requirement for you.

Develop

uv run mcp dev src/mcp_reqcheck/server.py

Opens the MCP Inspector, where you can call the tool, read the resource, and render the prompt without a client.

Layout

server.py holds the records, the rule catalog, the analyser, and the MCP surface in one module, with ambiguity_rules.yaml beside it. That is deliberate: a client may load the file directly (mcp run server.py, with no package around it) or run the installed console script (uvx mcp-reqcheck, with one), and imports between sibling files resolve differently in those two cases. Importing nothing of its own makes both behave identically.

Two details in that file must stay as they are, or the file-based launch breaks:

• no from __future__ import annotations — it turns annotations into strings, which dataclasses resolves through sys.modules[cls.__module__], and that is None for a directly-loaded file
• Pattern[str], not re.Pattern[str] — same reason

The catalog and analyser are copied from apps/api. Rule changes made there need copying here too.

Publishing

uv build
uv publish --index testpypi     # sandbox first
uv publish                      # then the real index