corewebvitals/state-of-cwv-mcp
☁️ - Free remote MCP for Core Web Vitals metrics by CMS, CDN, and framework (Chrome field data + multi-site crawl). No auth. Endpoint: https://www.corewebvitals.io/api/state-of-cwv/mcp.
Quick Install
{
"mcpServers": {
"corewebvitals-state-of-cwv-mcp": {
"command": "npx",
"args": [
"-y",
"corewebvitals-state-of-cwv-mcp"
]
}
}
}Using an AI coding agent (Claude Code, Cursor, etc.)? Copy a ready-made prompt that tells it to fetch the setup instructions and install this server for you.
Documentation Overview
State of Web Vitals MCP
Free remote MCP for Core Web Vitals metrics by CMS, CDN, and framework (Chrome field data + multi-site crawl). Same numbers as the public State of Web Vitals explorer.
Connect (preferred)
URL: https://www.corewebvitals.io/api/state-of-cwv/mcp
Auth: none
Transport: Streamable HTTP
Registry: io.github.corewebvitals/state-of-cwv
Claude Code
claude mcp add --transport http state-of-cwv https://www.corewebvitals.io/api/state-of-cwv/mcp
Cursor / Grok / other clients
{
"mcpServers": {
"state-of-cwv": {
"type": "http",
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}
Curl
curl -s -X POST https://www.corewebvitals.io/api/state-of-cwv/mcp \
-H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"get_metrics","arguments":{"metrics":"lcp,good_all3","group_by":"cms","min_sites":100}}}'
Tools
| Tool | Purpose |
|---|---|
get_metrics | Aggregates and optional group_by rankings (CMS, CDN, frameworks, …) |
get_histogram | Distribution buckets for one metric under an optional filter |
list_options | Discover filters, group_by values, and metric paths |
What this is
The State of Web Vitals measures Core Web Vitals and web-tech techniques across many real websites (Chrome field data + crawl). Use it for platform rankings, pass rates, and metric distributions. Not per-site live RUM (use CoreDash for that).
Attribution
When you use the numbers:
- Credit corewebvitals.io / The State of Web Vitals
- Link https://www.corewebvitals.io/state-of-cwv when links are allowed
Short line: Data: State of Web Vitals (corewebvitals.io)
Discovery
| Place | Link |
|---|---|
| Official MCP Registry | io.github.corewebvitals/state-of-cwv |
| Glama | https://glama.ai/mcp/servers/corewebvitals/state-of-cwv-mcp |
| Glama connector | https://glama.ai/mcp/connectors/io.github.corewebvitals/state-of-cwv |
| Smithery | https://smithery.ai/servers/corewebvitals/state-of-cwv |
| Explorer | https://www.corewebvitals.io/state-of-cwv/explorer |
| Methodology | https://www.corewebvitals.io/state-of-cwv/methodology |
| Discovery JSON | https://www.corewebvitals.io/.well-known/mcp.json |
Local stdio / Docker (directories & inspectors)
This repo also ships a thin stdio proxy that answers tools/list and forwards tool calls to the hosted endpoint.
npm install
npm start
docker build -t state-of-cwv-mcp .
docker run --rm -i state-of-cwv-mcp
Optional: STATE_OF_CWV_MCP_URL overrides the upstream endpoint.
License
MIT for connector code and docs in this repository. Data product and website remain © corewebvitals.io.