Google Crux MCP server
{
"mcpServers": {
"a1-x-tech-google-crux": {
"command": "npx",
"args": [
"-y",
"mcp-google-crux@latest"
],
"env": {
"CRUX_API_KEY": "<crux_api_key>"
}
}
}
}{
"mcpServers": {
"a1-x-tech-google-crux": {
"command": "npx",
"args": [
"-y",
"mcp-google-crux@latest"
],
"env": {
"CRUX_API_KEY": "<crux_api_key>"
}
}
}
}{
"mcpServers": {
"a1-x-tech-google-crux": {
"command": "npx",
"args": [
"-y",
"mcp-google-crux@latest"
],
"env": {
"CRUX_API_KEY": "<crux_api_key>"
}
}
}
}{
"servers": {
"a1-x-tech-google-crux": {
"command": "npx",
"args": [
"-y",
"mcp-google-crux@latest"
],
"env": {
"CRUX_API_KEY": "${input:crux_api_key}"
}
}
},
"inputs": [
{
"id": "crux_api_key",
"type": "promptString",
"description": "Crux api key",
"password": true
}
]
}{
"mcpServers": {
"a1-x-tech-google-crux": {
"command": "npx",
"args": [
"-y",
"mcp-google-crux@latest"
],
"env": {
"CRUX_API_KEY": "<crux_api_key>"
}
}
}
}file .mcp.json (in your project root)file claude_desktop_config.jsonfile ~/.cursor/mcp.jsonfile .vscode/mcp.jsonfile ~/.codeium/windsurf/mcp_config.jsoninstall npx -y mcp-google-cruxversion 1.1.0
What it does
This server exposes real-user Core Web Vitals data from Google's Chrome UX Report (CrUX) API. It lets developers check whether a URL passes Core Web Vitals metrics, compare performance across devices, and track metric trends over time.
- Check whether a public website or page passes Core Web Vitals thresholds on mobile or desktop.
- Compare Core Web Vitals performance between a specific page and its origin average.
- Track how LCP, INP, and CLS metrics have changed over the last 25 weeks.
Tools this server exposes
| Tool | Does |
|---|---|
| get_core_web_vitals | Retrieve p75 LCP, INP, and CLS metrics with pass/needs-improvement/poor ratings for a given URL and device type. |
| compare_devices | Compare Core Web Vitals metrics across phone, desktop, tablet, and all-device groups for a URL. |
| compare_origin_and_page | Compare Core Web Vitals performance of a specific URL against its origin average. |
| get_trend | Retrieve a 40-week trend of LCP, INP, and CLS metrics for a URL to track performance changes over time. |
| get_latest_record | Fetch raw CrUX histograms and percentiles for the current 28-day rolling window. |
| get_historical_record | Fetch raw CrUX histograms and percentiles for a specific week in the past. |
Before you enable it
An MCP server runs with whatever access you give it. Start with a development account rather than production, and check which tools the server exposes before you let an agent call them unattended.