
OpenCRAVAT
β 5from KarchinLab
Genetic variant annotation
OpenCRAVAT MCP Server
This repository contains an MCP (Model Context Protocol) server that exposes OpenCRAVAT-powered variant annotation as callable tools. It runs as a Cloudflare Worker (via Wrangler) and proxies requests to public OpenCRAVAT services.
What this server provides
It exposes MCP tools that let an MCP client:
- Discover which OpenCRAVAT annotators are being run (a curated default set).
- Inspect annotator output schemas (field names/types/descriptions).
- Annotate variants by:
- genomic coordinates (chrom/pos/ref/alt). Accepts only GRCh38/hg38 coordinates.
- dbSNP rsID
- ClinGen Allele Registry ID (CAid)
- HGVS (g./c./p.)
- Convert a protein missense notation (e.g., BRAF V600E) into candidate GRCh38 genomic HGVS changes (via SynVar), which you can then pass to HGVS annotation.
Connecting
This MCP server is hosted remotely at
https://mcp.opencravat.org/mcpIt can also be run locally.
Claude
To connect to Claude, follow these instructions. Use the URL above, and do not set up auth. No user-specific data is needed for the MCP to work. Remember to enable the MCP for your chat.
ChatGPT
To connect with ChatGPT, you must enable developer mode, then add a custom app:
- Open Settings
- Go to Apps
- In Advanced Settings, use the toggle to turn on βDeveloper Modeβ
- Click Create App
- Use the URL above as the βMCP Server URLβ
- Set Authentication to βNo Authβ
- Add a name to the MCP App that youβll easily recognize, such as βOpenCRAVATβ
You will have to add the MCP to a new chat using the + icon in the lower left of the chat box.
npm installRunning Locally
Prerequisites:
- Node.js (recent enough for modern TypeScript tooling; Node 18+ recommended)
- npm
Install dependencies:
npm installStart the dev server (Wrangler):
npm startBy default, your MCP endpoint will be:
http://localhost:8787/mcpConnect Claude Desktop
To connect to your MCP server from Claude Desktop, follow Anthropic's Quickstart and within Claude Desktop go to Settings > Developer > Edit Config.
Update with this configuration:
{
"mcpServers": {
"OpenCRAVAT": {
"command": "npx",
"args": [
"mcp-remote",
"http://localhost:8787/mcp"
]
}
}
}Restart Claude and you should see the tools become available.
No common issues documented yet. If you hit a problem, the repository's GitHub Issues page is the best place to look.