MDN MCP server
Commit Nov 13, 2026Provides LLMs and coding agents with access to MDN's web platform documentation, search, and browser compatibility data.
Also known as mdn/mcp
- Stars
- 197
- Tools
- —
- Downloads, 30 days
- —
- Latest version
- —
- Last commit
- Nov 13, 2026
- License
- MPL-2.0
What is MDN MCP?
MDN provides LLMs and coding agents with access to MDN's web platform documentation, search, and browser compatibility data.
Summary generated from the project's README
About MDN MCP server
Accessing accurate web platform documentation and browser compatibility data directly from MDN is what this server enables for developers using LLMs and coding agents. It serves as a reliable alternative to the potentially outdated training data found in standard language models by providing real-time access to MDN's search and documentation resources.
Users can connect to a remote instance via HTTP or run the server locally using npm. For those using Claude Code, the setup involves adding the server with specific transport commands for either the hosted version or a localhost address. Because this is an experimental service, it collects query data that is not associated with user identity, though users can opt out of first-party analytics by sending a specific header. This tool is designed for developers who need to verify web standards and browser support through their AI clients.
What you can do with it
- 1Verify web API compatibilityAsk an AI agent to check if a specific web feature is supported across different browsers using MDN data.
- 2Retrieve up-to-date web documentationRequest the latest technical specifications for a web standard to avoid using outdated training data.
- 3Search MDN content via AIDirect a coding agent to find specific information within the MDN web platform documentation.
Written from the project's README. Every use case is checked against a quote from it.
Automated checks
Ran Nov 13, 2026Full report →Not verified yet. A server needs a score of 80, no serious finding, and enough data for us to check. How checks work · What to fix for more points
- Source repository linked and reachablemdn/mcp is public and reachablegithub.com/mdn/mcp ↗Pass
- Package names this repository as its sourceNot checked
- Build provenance (Sigstore attestation)Not checked
- Open source license (OSI)MPL-2.0spdx.org/licenses/MPL-2.0.html ↗Pass
- Commit or release in the last yearLast commit or release 2026-11-13github.com/mdn/mcp ↗Pass
- OpenSSF ScorecardNot checked
- Package name not close to a popular packageNot checked
- No critical advisory in the package or its dependenciesNot checked
- No hidden instructions to the model0 tool descriptions and the README read; no override phrases, credential paths or hidden charactersPass
- Destructive tools are labelledNot checked
- Remote endpoint answers the MCP handshakeNot checked
README
View on GitHubMDN MCP server
This is an experimental MCP server that provides access to MDN's search, documentation, and browser compatibility data.
Our goal is to give LLMs and coding agents a reliable and up-to-date source of web platform documentation - so developers can get accurate information instead of potentially outdated content their LLMs were trained on.
Privacy and data retention
This MCP server is being run as an experiment. While it is an experiment, we will be storing data about the queries we receive. Please see our privacy notice for more information on interaction data we may collect. This data will not be associated with any information designed to identify users. However, while unlikely, it is possible that private information that you divulge to the LLM could be included in these queries. If this is a concern to you, we recommend not using this MCP server.
To opt out of first-party analytics, send the X-Moz-1st-Party-Data-Opt-Out: 1 header along with requests to the MCP.
By using our MCP server, you agree to comply with our Acceptable Use Policy.
As this MCP server is experimental, it may be withdrawn at any time.
Using the remote server
Add the remote server to your tool of choice. For example, in Claude Code:
claude mcp add --transport http mdn https://mcp.mdn.mozilla.net/
Browser clients can connect directly using Streamable HTTP, without a CORS proxy.
Using locally
- Install dependencies:
npm install - Start the server:
npm start
Add the server to your tool of choice. For example, in Claude Code:
claude mcp add --transport http mdn-local http://localhost:3002/
Local development
- Install dependencies:
npm install - Start the development server, MCP inspector, and tests:
npm run dev
Your browser should automatically open the MCP inspector, and the server will restart when you make changes.
MDN MCP questions
How can I opt out of first-party analytics?
You can opt out by sending the X-Moz-1st-Party-Data-Opt-Out: 1 header along with your requests to the MCP.
Is my data private when using this server?
While query data is stored for the experiment, it is not associated with information designed to identify users, though private information shared with the LLM could be included in queries.