Baseline MCP Server

A server for querying baseline web features data. It is built using the @modelcontextprotocol/sdk and uses the web-features package as a data source. It was built for the Baseline Tooling 2025 Hackathon.

Prerequisites

• For local development, you will also need Node.js and npm.

Usage

There are two ways to use the Baseline MCP Server:

1. Demo Client: Try the demo client at https://baseline-mcp-demo.web.app/.
2. Your Own Client: You can connect your own MCP-compatible client to the server. See the "Connecting a Client" section below for details.

Connecting a Client

Use the accordion below to configure your client.

In your ~/.gemini/settings.json, add one of the following objects to the mcpServers array.

{
  "name": "baseline-mcp",
  "command": ["npx", "mcp-remote", "https://baseline-mcp.netlify.app/mcp"]
}

In your settings.json or .vscode/mcp.json, add the following configuration.

"mcp": {
  "servers": {
    "baseline-mcp": {
      "command": "npx",
      "args": ["mcp-remote", "https://baseline-mcp.netlify.app/mcp"]
    }
  }
}

Development

If you want to modify or contribute to this tool, follow these instructions for a local setup.

Installation

1. Clone the repository: git clone <repository-url>
2. Navigate to the project directory: cd baseline-mcp

Running Locally

1. Install dependencies:

   npm install
   

2. Build the server:

   npm run build
   

3. Run the server:

   npm start
   

Inspecting the Server

To inspect the server's capabilities, you can use the inspect script. This is useful for seeing the full list of tools and prompts that the server exposes.

npm run inspect

Interacting with the Server

Once the server is running, you can send JSON-RPC requests to it. The server exposes the following tools and prompts:

Prompts

• create-study-guide: Creates a study guide for web features.
• find-features-in-file: Finds baseline features in a given file or directory.
• suggest-baseline-features: Suggests baseline features based on a description of a goal.
• min-browser-support-report: Get the minimum browser support for features in a set of files and display it as a report.

Tools

Feature Queries

• list-features: Returns a list of all available baseline web features.
• discouraged-features: Returns a list of all web features that are discouraged from use.
• get-feature-details: Gets all the details for a specific web feature.
• get-feature-by-status: Gets all web features with a specific baseline status.
• get_features_by_caniuse_id: Gets a web-features feature by its corresponding caniuse.com feature ID.
• get_features_with_spec_url: Gets all web features that reference a specific specification URL.
• get_features_by_compat_feature: Gets a web-features feature by its corresponding @mdn/browser-compat-data feature key.
• get_baseline_high_since: Gets all web features that reached "baseline high" status (widely supported) since a given date.
• get_baseline_low_since: Gets all web features that reached "baseline low" status (newly supported) since a given date.
• get_baseline_low_last_30_days: Gets all web features that reached 'baseline low' status in the last 30 days.
• get_baseline_high_last_30_days: Gets all web features that reached 'baseline high' status in the last 30 days.
• get_baseline_status_changes_last_30_days: Lists all web features that have changed their baseline status in the last 30 days, showing the transition.
• get_features_by_description_keyword: Searches for a keyword only in the description of the web features.
• get_features_by_name_keyword: Searches for a keyword only in the name of the web features.
• get_features_with_multiple_spec_urls: Returns web features that have more than one specification URL.
• get_features_with_no_spec_url: Returns web features that have no specification URL.
• get_features_with_alternatives: Returns all discouraged web features that have recommended alternatives.
• get_feature_alternative: Gets the recommended alternatives for a discouraged web feature.
• get_random_feature: Returns a random web feature.
• list_features_in_file: Analyzes the provided file content and lists the baseline web features used within it.
• suggest_baseline_feature: Suggests a baseline web feature based on a query using keyword matching.

Browser Compatibility

• get_latest_browser_versions: Returns the latest version of each major browser.
• check_feature_support: Checks in which version a browser started supporting a specific web feature.
• get_unsupported_features: Returns a list of web features not supported by a given browser.
• get_recently_supported_features: Returns a list of web features that were newly supported in a given browser version.
• compare_browser_support: Compares browser support for two or more web features.
• get_browser_release_dates: Returns a list of release dates and versions for a given browser.
• get_browser_release_date: Returns the release date for a specific browser version.
• get_features_not_supported_by_any_browser: Returns web features not supported by any major browser.
• generate_browser_support_matrix: Generates a simplified browser support matrix for a given list of web features across major browsers.
• get_min_browser_support_for_file: Analyzes file content to determine the minimum browser version required to support all detected web features.

Feature Groups and Snapshots

• get_feature_groups: Returns a list of all available feature groups.
• get_features_by_group: Gets all web features in a specific group.
• list_snapshots: Returns a list of all available snapshots.