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

This tool can be used via npx for a quick, installation-free experience.

This method requires authenticating with GitHub Packages once.

1. Create a Personal Access Token (PAT) with the read:packages scope.

2. Create or edit the .npmrc file in your user home directory (~/.npmrc) and add the following lines, replacing YOUR_PERSONAL_ACCESS_TOKEN with your token.

   @Technickel-Dev:registry=https://npm.pkg.github.com/
   //npm.pkg.github.com/:_authToken=YOUR_PERSONAL_ACCESS_TOKEN

Once authenticated, you can run the server directly:

npx @Technickel-Dev/baseline-mcp

Connecting a Client

Use the accordion below to configure your client.

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

"mcp": {
  "servers": {
    "baseline-suggester": {
      "command": "npx",
      "args": ["@Technickel-Dev/baseline-mcp"]
    }
  }
}

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

{
  "type": "stdio",
  "name": "baseline-suggester",
  "command": ["npx", "@Technickel-Dev/baseline-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. Run the server:

   npm start

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.