State of Web Vitals is an MCP server with 3 tools an agent can call, among them get_histogram, get_metrics, list_options. It answers at https://www.corewebvitals.io/api/state-of-cwv/mcp over streamable HTTP, and it listed its tools to an anonymous client, so no sign-in was needed for that. Our probes reached it 6 of 6 times since 11 September 2026; the last check, on 21 October 2026, succeeded.
Core Web Vitals metrics by CMS, CDN, and framework — free remote MCP, no auth.
Description as the publisher wrote it.
| Tool | What it does |
|---|---|
get_histogram | What is the shape of one metric? Returns histogram buckets (count + share) plus summary stats. Metric: one of lcp, inp, cls, fcp, ttfb (field CWV), or a scalar technique path when available. Filter: same as get_metrics (device, cms, framewo Inputs: metric, filter |
get_metrics | What are the numbers? Aggregate Core Web Vitals and/or technique metrics across sites, with optional filter and group_by. Responses include attribution — credit corewebvitals.io when you use the numbers. Metrics (comma-separated or array): Inputs: metrics, filter, group_by, focus, limit, min_sites |
list_options | Discover what you can pass to get_metrics / get_histogram: filter keys, group_by values, built-in metrics, and contract metric paths (optional kind filter). Call this when unsure of a key or path. Inputs: kind, include_paths |
Every block below points at https://www.corewebvitals.io/api/state-of-cwv/mcp. Pick your client and copy.
claude mcp add --transport http state-of-web-vitals https://www.corewebvitals.io/api/state-of-cwv/mcp
{
"mcpServers": {
"state-of-web-vitals": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://www.corewebvitals.io/api/state-of-cwv/mcp"]
}
}
}{
"mcpServers": {
"state-of-web-vitals": {
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}{
"servers": {
"state-of-web-vitals": {
"type": "http",
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}{
"context_servers": {
"state-of-web-vitals": {
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}{
"mcpServers": {
"state-of-web-vitals": {
"serverUrl": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}{
"mcpServers": {
"state-of-web-vitals": {
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}name: State of Web Vitals
version: 0.0.1
schema: v1
mcpServers:
- name: State of Web Vitals
type: streamable-http
url: https://www.corewebvitals.io/api/state-of-cwv/mcp{
"mcpServers": {
"state-of-web-vitals": {
"httpUrl": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}{
"mcpServers": {
"state-of-web-vitals": {
"type": "http",
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}{
"mcpServers": {
"state-of-web-vitals": {
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
}goose://extension?url=https%3A%2F%2Fwww.corewebvitals.io%2Fapi%2Fstate-of-cwv%2Fmcp&type=streamable_http&id=state-of-web-vitals&name=State%20of%20Web%20Vitals
It answered our last check on 21 October 2026 in 119 ms. Over 6 checks since 11 September 2026 it answered 6. Status here comes from Neuronto's own probes, not from the publisher.
3, as returned by the server's own tools/list on 13 September 2026: get_histogram, get_metrics, list_options.
It answered our last check on 21 October 2026 in 119 ms. Over 6 checks since 11 September 2026 it answered 6.
Put the server under mcpServers in ~/.cursor/mcp.json with the URL https://www.corewebvitals.io/api/state-of-cwv/mcp. The exact JSON is above, with the same setup for Claude Code, Claude Desktop, VS Code, Windsurf, Zed, Gemini CLI and the rest.
It listed its tools to an anonymous client, so reading the tool list needs no key. Individual tools can still ask for credentials in their own inputs.
Publisher: io.github.corewebvitals. Endpoint host: www.corewebvitals.io. ARD identifier: urn:air:io.github.corewebvitals:mcp:state-of-cwv.
First indexed 10 September 2026. The tools are exactly what the server returned; nothing on this page
is inferred from its name. Ranking in Neuronto search is never for sale.