# State of Web Vitals

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

- name: io.github.corewebvitals/state-of-cwv
- version: 1.0.1
- connection class: R0 (autonomous)
- trust: 90/100
- quality: 85/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/io.github.corewebvitals%2Fstate-of-cwv
- tools: https://api.protogrid.dev/v1/servers/io.github.corewebvitals%2Fstate-of-cwv/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

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


## Trust

- hygiene: 100
- liveness: 100
- freshness: 65
- provenance: 90
- drivers: +repository +namespace-matches-repo +website +reachable +uptime-100% ~updated-96d-ago
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 85/100 (good)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-03-26; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 86 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 3 of 3 tools declare readOnlyHint or destructiveHint
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: get_metrics (idempotentHint, openWorldHint); get_histogram (idempotentHint, openWorldHint); list_options (idempotentHint, openWorldHint)
- pass `tools.token_cost`: about 1,105 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 3, about 1,105 tokens to load them all
- tool set hash: 4ea3eb1f62614aead216af642d1290c3
- badge: [![protogrid quality](https://protogrid.dev/badge/io.github.corewebvitals/state-of-cwv.svg)](https://protogrid.dev/servers/io.github.corewebvitals/state-of-cwv)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://www.corewebvitals.io/api/state-of-cwv/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (3)

- `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, framework, cdn, provider). No group_by — call get_metrics with group_by to compare segments, then get_histogram per segment if needed.
- `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):
- CWV: lcp, inp, cls, fcp, ttfb — good/needs_improvement/poor share + p50/p75 + sample n
- good_all3 — share of sites that pass LCP+INP+CLS together
- good_all3_plus_ttfb — pass all three plus TTFB
- Contract paths: images.loading, stack.framework, scripts.origin, headers.has_etag, synthetic.tbt_ms, …

Filter (optional AND): device, cms, framework, cdn, provider. Omit = all sites in the snapshot.
Group_by (optional): cms | frameworks | cdn | analytics | tag_managers | … → one row per entity.
Without group_by: one aggregate; set metrics return top categories.
- `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.