State of Web Vitals
REMOTE · WWW.COREWEBVITALS.IO · SCANNED AUG 3
Core Web Vitals metrics by CMS, CDN, and framework — free remote MCP, no auth.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score →
Endpoint Security80
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability55
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 1367 tokens (~455/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management27
- Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Capabilities40
- Spec-recency check failed: implements MCP spec 2025-03-26; the latest is 2026-07-28. See how to fix → Fail
Add this component to your MCP client. Where a client-specific snippet is available, pick your client below and copy it straight into your config; otherwise use the connection detail shown.
remote · www.corewebvitals.io
claude mcp add --transport http corewebvitals-state-of-cwv https://www.corewebvitals.io/api/state-of-cwv/mcp
[mcp_servers.corewebvitals-state-of-cwv] url = "https://www.corewebvitals.io/api/state-of-cwv/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"corewebvitals-state-of-cwv": {
"type": "remote",
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp",
"enabled": true
}
}
} openclaw mcp add corewebvitals-state-of-cwv --url https://www.corewebvitals.io/api/state-of-cwv/mcp --transport streamable-http
mcp_servers:
corewebvitals-state-of-cwv:
url: "https://www.corewebvitals.io/api/state-of-cwv/mcp" {
"mcpServers": {
"corewebvitals-state-of-cwv": {
"type": "http",
"url": "https://www.corewebvitals.io/api/state-of-cwv/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 3 Aug 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.
- 31 Jul 26 +4
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.
- 28 Jul 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.
- 27 Jul 26 +1
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Jul 26 61
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 3 Aug 2026 · Probed https://www.corewebvitals.io/api/state-of-cwv/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=corewebvitals.io | CN=WE1,O=Google Trust Services,C=US | 25 Jul 2026 | 23 Oct 2026 | ECDSA 256 | ECDSA-SHA256 | cb3084d6a2934265138a81009ddd0634 |
| SANs: corewebvitals.io, *.corewebvitals.io | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
DNSSEC insecure
Validation of www.corewebvitals.io. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| io. | present | 57355 | 8 | Verified |
| corewebvitals.io. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=63072000; includeSubDomains; preload |
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://www.corewebvitals.io/api/state-of-cwv/mcp | Verified | 200 | |
| http (plaintext) | http://www.corewebvitals.io/api/state-of-cwv/mcp | HTTPS enforced | 301 | https://www.corewebvitals.io/api/state-of-cwv/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability.
get_histogram ~188
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.
| Name | Type | Req | Description |
|---|---|---|---|
| filter | object | — | 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; pr… |
| metric | string | yes | lcp | inp | cls | fcp | ttfb, or a contract scalar path. |
No output schema declared.
No examples provided.
get_metrics ~416
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.
| Name | Type | Req | Description |
|---|---|---|---|
| filter | object | — | 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; pr… |
| focus | string | — | CWV used when correlating technique metrics. Default: lcp. |
| group_by | string | — | Break results down by this dimension: cms, frameworks, cdn, or a provider category (analytics, tag_managers, …). Omit for a single aggregate. |
| limit | integer | — | Max groups or top categories. Default: 25, max: 100. |
| metrics | — | — | Metrics to return. Default: lcp,inp,cls,ttfb,good_all3. String (comma-separated) or array of strings. |
| min_sites | integer | — | When group_by is set, drop groups with fewer sites. Default: 50. |
No output schema declared.
No examples provided.
list_options ~90
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.
| Name | Type | Req | Description |
|---|---|---|---|
| include_paths | boolean | — | Include full contract path list. Default true. |
| kind | string | — | Optional contract kind: scalar, boolean, categorical, set, weighted_set, measures. |
No output schema declared.
No examples provided.