Core Web Vitals metrics by CMS, CDN, and framework — free remote MCP, no auth.

🛠️ Key Features

Model Context Protocol (MCP) server providing remote, streamable HTTP CP data
Focused on Core Web Vitals metrics (LCP, CLS, FID) across CMS, CDN, and frameworks
No authentication required; accessible remotely for integration
Described by a concise readme excerpt and structured metadata

🚀 Use Cases

Retrieve real-time Core Web Vitals context for performance dashboards
Compare metrics across different CMS and CDN configurations
Integrate MCP data into tooling for performance optimization workflows

⚡ Developer Benefits

Lightweight, remote MCP endpoint with minimal setup
Clear topics alignment: core-web-vitals, lcp, mcp, model-context-protocol, streamable-http, web-performance
Reusable in performance analysis pipelines and monitoring tools

⚠️ Limitations

Description indicates free remote MCP with no auth; verify access controls for sensitive data
Source data provides limited scope; deeper metrics or historical data may require additional sources

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

bash

claude mcp add --transport http state-of-cwv https://www.corewebvitals.io/api/state-of-cwv/mcp

Cursor / Grok / other clients

json

{
  "mcpServers": {
    "state-of-cwv": {
      "type": "http",
      "url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
    }
  }
}

Curl

bash

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.

bash

npm install
npm start

bash

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.

kind	string	optional	Optional contract kind: scalar, boolean, categorical, set, weighted_set, measures.
include_paths	boolean	optional	Include full contract path list. Default true.

State of Web Vitals

🛠️ Key Features

🚀 Use Cases

⚡ Developer Benefits

⚠️ Limitations

Topics

get_metrics

get_histogram

list_options

State of Web Vitals MCP

Connect (preferred)

Claude Code

Cursor / Grok / other clients

Curl

Tools

What this is

Attribution

Discovery

Local stdio / Docker (directories & inspectors)

License

Install

Remote endpoint

metrics	any	optional	Metrics to return. Default: lcp,inp,cls,ttfb,good_all3. String (comma-separated) or array of strings.
filter	object	optional	AND filters. Omit for all sites in the dataset. Keys: device (all\|phone\|desktop), cms, framework, cdn, provider (key), provider_category (e.g. analytics — use with provider or alone is not enough; prefer group_by for rankings).
group_by	string	optional	Break results down by this dimension: cms, frameworks, cdn, or a provider category (analytics, tag_managers, …). Omit for a single aggregate.
focus	string	optional	CWV used when correlating technique metrics. Default: lcp.
limit	integer	optional	Max groups or top categories. Default: 25, max: 100.
min_sites	integer	optional	When group_by is set, drop groups with fewer sites. Default: 50.

metric	string	required	lcp \| inp \| cls \| fcp \| ttfb, or a contract scalar path.
filter	object	optional	AND filters. Omit for all sites in the dataset. Keys: device (all\|phone\|desktop), cms, framework, cdn, provider (key), provider_category (e.g. analytics — use with provider or alone is not enough; prefer group_by for rankings).