CRAN MCP

A Model Context Protocol server that provides up-to-date R package documentation, package status information and R release information directly from CRAN.

The server is stateless: it fetches current CRAN data on demand and returns only the relevant information to the MCP client.

Tools

• search_packages(query, limit=20) searches all current CRAN package names and short descriptions and ranks matching packages.
• get_package_info(package) returns the package title, description, current version, CRAN publication date and dependency groups (Depends, Imports, Suggests, LinkingTo, Enhances).
• get_package_news(package, version=None, max_chars=50000) returns the package NEWS/changelog page from CRAN, optionally restricted to one version such as 1.18.4.
• get_package_check_status(package) returns the current CRAN check status, status counts and results for every check flavor.
• get_package_topics(package, query=None, limit=100) lists help topics from a CRAN package.
• get_topic_documentation(package, topic, max_chars=30000) returns one help topic as plain text with its CRAN source URL.
• search_package_documentation(package, query, limit=10) searches the reference manual and returns matching snippets.
• get_r_versions(major=None, limit=100) lists R releases available from CRAN, optionally restricted to a major version such as 4.
• get_r_version_news(version, max_chars=50000) returns the official R NEWS section for one R release, for example 4.5.1.

Package discovery

search_packages() uses the same machine-readable CRAN package database as tools::CRAN_package_db() in R:

https://cran.r-project.org/web/packages/packages.rds

The RDS database contains the package metadata for current CRAN packages. The search uses Package and Title, where Title is the short package description shown in CRAN's package-by-name list. The RDS file is parsed directly in Python; R is not required at runtime.

Examples:

search_packages("survival model")
search_packages("arrow", limit=10)

R releases

get_r_versions() reads the official CRAN R source directories, so the version list is not hard-coded.

Examples:

get_r_versions()
get_r_versions(major=4)
get_r_version_news("4.5.1")

Local setup

uv sync --dev
uv run cran-mcp

The MCP endpoint is available at http://127.0.0.1:8000/mcp.

Docker

docker build -t cran-mcp .
docker run --rm -p 8000:8000 -e MCP_ALLOWED_HOSTS=localhost,localhost:* cran-mcp

Environment variables

• PORT: HTTP port, default 8000.
• MCP_ALLOWED_HOSTS: comma-separated allowed Host values for public deployment.
• MCP_ALLOWED_ORIGINS: optional comma-separated allowed browser origins.

Examples

search_packages("Bayesian survival")
get_package_info("data.table")
get_package_news("data.table")
get_package_news("data.table", version="1.18.4")
get_package_check_status("data.table")
get_topic_documentation("data.table", "fread")
get_r_versions(major=4)
get_r_version_news("4.5.1")

MCP client
    |
    | package / R release request
    v
CRAN MCP
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    | HTTPS
    v
CRAN package database, package pages, NEWS, checks, R source index and HTML reference manuals