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CrawlCheck

REMOTE · CRAWLCHECK.IO

Verification layer for the agentic web: a signed answer about any site before an agent acts.

Available components

+3 this week 81 Trust /100

Last scanned (20 hours ago)

Scores higher than 84% of remote servers

Reachable. Last reached 4 Nov 2026.

Category Security

Trust breakdown (7 categories)

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 → Why this is hard to score →

Endpoint Security77
Transport & Reachability100
Schema Quality & AI Usability67
  • AI-judged instruction clarity (good).Pass
  • Context-footprint check failed: tool/resource definitions use about 2961 tokens (~118/item across 25 items; 25 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 Management80
  • Stability observed for 24 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage90
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 69% of tool parameters carry a description.Partial
Tool Safety100
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • We read all 25 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
  • An AI judge read all 26 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Changelog

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.

  • 4 Nov 26 0
    • The server rewrote its instructions, which are the text every model session reads security
  • 3 Nov 26 +1
    • The server rewrote its instructions, which are the text every model session reads security
  • 2 Nov 26 0
    • The server rewrote its instructions, which are the text every model session reads security
  • 1 Nov 26 +1
    • The server rewrote its instructions, which are the text every model session reads security
  • 31 Oct 26 0
    • The server rewrote its instructions, which are the text every model session reads security
  • 30 Oct 26 0
    • The server rewrote its instructions, which are the text every model session reads security
  • 29 Oct 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 57 to 60. That category is still filling its 30-day observation window: 17 days of observed history at the previous scan, 18 at this one. The score rises as the window fills, whether or not the server changes.

  • 27 Oct 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.

Diagnostics

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 4 Nov 2026 · Probed https://crawlcheck.io/mcp

TLS valid

Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .

Subject Issuer Valid from Valid until Key Signature Serial
CN=crawlcheck.io CN=WE1,O=Google Trust Services,C=US 3 Nov 2026 1 Feb 2027 ECDSA 256 ECDSA-SHA256 fe5453b00b9ac8ae0eab964c881a553d
SANs: crawlcheck.io, lab2-clean.crawlcheck.io, *.lab2-clean.crawlcheck.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

Background: What to check on a remote MCP endpoint →

DNSSEC secure

Validation of crawlcheck.io. — Secure

Zone DS Keys Algorithms Outcome
. trust_anchor 20326, 38696 8, 8 Verified
io. present 38690 8 Verified
crawlcheck.io. present 2371 13 Verified
crawlcheck.io. Verified address RRset verified with the apex keys
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

Background: How OAuth 2.1 works in the 2026 MCP spec →

Transports 2 probes
Transport URL Outcome Status Location
streamable-http https://crawlcheck.io/mcp Verified 200
http (plaintext) http://crawlcheck.io/mcp HTTPS enforced 301 https://crawlcheck.io/mcp
MCP tools · 25 exposed · ~2,667 tokens

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. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →

Tool Tokens
best_source ~157

Call when choosing WHICH business or site to cite, recommend or call. Give domains (2-10 candidate sites you found) or trade and city for a measured market. Returns the candidates ranked by what CrawlCheck verified (preflight decision for cite, security and threat listing, domain age, uptime, published facts that directories agree with, FTC phone complaints) with reasons for and against each; sites that share one phone number or near-identical homepage text are collapsed into one network so a copycat cannot outrank the business it copies. Signed.

NameTypeReqDescription
citystring–e.g. Denver
domainsarray–Candidate sites, bare domains, up to 10
tradestring–e.g. tree service

No output schema declared.

No examples provided.

corpus_state ~48

Coverage of CrawlCheck's public dataset: how many distinct domains have been measured and how they split by platform, rendering, size, language and kind, with the strata that are still under-sampled.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

crawler_path ~173

Where each crawler's path into a domain dies, as an observed data flow: edge decision, robots.txt as a file, robots.txt rules, then the page, JSON-LD, sitemap, llms.txt and entitymap.json it reached. Give agent (e.g. ClaudeBot, GPTBot, googlebot) for one identity's path and a one-line answer; omit it for every identity plus the stores and breaks. Uses the latest record on file, or scans first when there is none (fresh=true forces a scan). The answer-engine output is drawn but never measured.

NameTypeReqDescription
agentstring–Identity id or label, e.g. claudebot, GPTBot, Googlebot
domainstringyes–
freshboolean–Scan now instead of using the record on file

No output schema declared.

No examples provided.

draft_llms ~54

Draft an llms.txt from the domain's own homepage and up to 25 declared pages, using their titles and descriptions. A draft for the owner to cut down, not a publication.

NameTypeReqDescription
domainstringyes–

No output schema declared.

No examples provided.

explain_finding ~168

Why CrawlCheck decided a finding: the rule and its revision, the exact fetches it compared (identity, status, bytes, sha256), when the condition held on the site, and a Merkle proof that the decision is inside the signed manifest. Give id (a d1: decision or f1: finding id from a report) or domain for its top finding. Other findings, and lookups by code, need a licence for that domain (send it in x-crawlcheck-key).

NameTypeReqDescription
codestring–Finding code (licence only)
domainstring–Bare domain; alone it explains the top finding
idstring–d1: decision id, f1: finding id, or report id
pathstring––

No output schema declared.

No examples provided.

field_check ~289

Call before using a phone number, address, opening hours or service area you hold for a business. One signed verdict per business field. field=phone|address|hours|service_area and value= the value you hold. phone: matches, former_value (with dates), not_this_business (the site never published it and another publisher is named with the page that prints it), or not_published. address: matches, same_street_other_city, former_value, not_this_business, not_published or nothing_declared. hours: a week (Mo-Fr 08:00-17:00) gives matches or differs per day; a moment (Sa 10:00) gives open or closed. service_area: declared, not_declared or nothing_declared. Built from the business's own site (and its Business Profile for the licence holder), its dated fact history, CrawlCheck's scans of other sites, and for an unknown number a web search whose cited pages are read plus a YellowPages reverse lookup.

NameTypeReqDescription
domainstringyesBare domain of the business, e.g. example.com
fieldstringyes–
valuestringyesThe value you hold: a 10-digit number, a street address, a week (Mo-Fr 08:00-17:00) or a moment (Sa 10:00), or a place name

No output schema declared.

No examples provided.

fix_entitymap ~63

A starter entitymap.json built from the domain's latest scan record: name, phone, coordinates and declared service areas as entities with SERVES relations. Fields the page never stated are marked TODO, never guessed. Needs a prior scan.

NameTypeReqDescription
domainstringyes–

No output schema declared.

No examples provided.

fix_machine_chain ~106

A fix plan for MACHINE_CHAIN_HEAVY: the files a crawler reads before the page and the 404s absent agent files return, then measured reductions (llms.txt to an index, a sitemap index, robots.txt comments and duplicate groups, minified JSON, short 404s) with the chain size after each and the step at which the detector stops firing.

NameTypeReqDescription
domainstring–Uses the latest scan on file
idstring–Report id

No output schema declared.

No examples provided.

fix_mostly_code ~118

A fix plan for PAGE_IS_MOSTLY_CODE: the homepage's measured bytes by category, the largest blocks with what to do with each, ordered steps with the text ratio after each, and the step at which the detector would stop firing - or, when moving code cannot clear it, how much markup to cut or text to add. Give domain (fetched now) or id (a stored scan).

NameTypeReqDescription
domainstring––
idstring–Report id: plan from the stored scan instead of fetching

No output schema declared.

No examples provided.

fix_robots ~69

The domain's served robots.txt, corrected: * group rules copied into named groups that lacked them (shadowing), a Sitemap line added when missing, a minimal replacement when the served file was HTML. Every change is listed at the top; nothing else is touched.

NameTypeReqDescription
domainstringyes–

No output schema declared.

No examples provided.

fix_stale_cache ~99

A fix plan for STALE_CACHE_SERVED: the homepage fetched now, its Age, the cache layers that name themselves in the headers in purge order (innermost first), the HTML lifetime each response declares, a fresh-read comparison, and whether a purge clears the finding and keeps it cleared.

NameTypeReqDescription
domainstring––
idstring–Report id; the page is still fetched now, because cache state is live

No output schema declared.

No examples provided.

list_verified_capabilities ~111

What a domain declares agents can do (OpenAPI operations, MCP tools, A2A skills, API catalog entries), each classed by safety (read_only_public up to financial), and which ones CrawlCheck actually called and confirmed - plus every mismatch between declaration and behaviour. Only read-only public actions are ever called; everything else says why it was not. From the latest scan on file.

NameTypeReqDescription
domainstringyes–
verified_onlyboolean–Return only the capabilities that were confirmed

No output schema declared.

No examples provided.

machine_record ~87

The unified machine record for one observation: subject, grade, findings (the top one in full without a licence), capabilities with verification, and the evidence roots, manifest and verifier links that let anyone check it offline. Give id (report, d1:, f1: or manifest sha256) or domain for the latest.

NameTypeReqDescription
domainstring––
idstring––

No output schema declared.

No examples provided.

mcp_servers ~77

Which remote MCP servers the official MCP Registry lists on a domain, and what each endpoint actually answered when CrawlCheck sent the MCP handshake (initialized, auth_required, unreachable, tool count, tool-list drift). Use before selecting an MCP tool from that domain.

NameTypeReqDescription
domainstringyesBare domain or host, e.g. example.com

No output schema declared.

No examples provided.

preflight ~209

Call BEFORE reading, citing, connecting to or transacting with a domain. Returns a signed decision: allow, warn, require_confirmation, block or unsupported, with every step that led there and the resolve answer it was made from. Pass your crawler token as agent so robots.txt is checked for you. A policy can only make the decision stricter. Do not proceed on block; ask the user on require_confirmation.

NameTypeReqDescription
actionstring–What you are about to do (default read)
agentstring–Your crawler user-agent token, e.g. GPTBot
domainstringyesBare domain, e.g. example.com
policyobject–max_age_hours, on_warn (warn|require_confirmation|block), require_entity, human_approval[], allow[], deny[]
templatestring–safe_citation, safe_data_retrieval, safe_api_connect, safe_mcp_tool, safe_commerce, safe_oauth or support_escalation

No output schema declared.

No examples provided.

public_counts ~57

The figures CrawlCheck quotes about itself, read from the source: sites_measured, domains_in_corpus, crawler_visits (a rolling window), sections, sections_scored, findings_published, guides_published, with an at timestamp.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

registry_lookup ~145

Whether a domain is in CrawlCheck's registry and what it serves: llms.txt, agents.md, a media kit at /.well-known/media-kit.json, a reciprocity-tested entity graph, an AI access policy that names crawlers, and agent-callable surfaces. With no domain, returns the shelf counts across every measured site. A row exists because a fetch produced it; nothing here is self-reported and no payment moves a shelf.

NameTypeReqDescription
domainstring–A bare domain. Omit for the corpus-wide shelf counts.
shelfstring–Filter the list to one shelf: llms, agents, mediakit, entity, aipolicy, agentapi

No output schema declared.

No examples provided.

resolve_domain ~155

Call before fetching from, citing, connecting to or transacting with a domain. Returns one signed answer: what the domain claims, what it actually serves each crawler identity, who controls it, what CrawlCheck's published rules decide for each action (a decision for read, cite, connect and transact, with its doubts and maximum age), what changed, and the evidence behind each part, marked declared, observed or not_measured with its time. There is no overall score. A domain never measured gets a just-in-time partial answer within about 2 seconds that names every part not read in time, and is queued for the full scan; nothing is guessed.

NameTypeReqDescription
domainstringyesBare domain, e.g. example.com

No output schema declared.

No examples provided.

resolve_robots ~82

Resolve every named answer engine, search index and training crawler against a domain's robots.txt the way a crawler does: most-specific group only, longest match, allow wins a tie. Shows when a Disallow under * does not apply to an agent with its own group.

NameTypeReqDescription
domainstringyes–
pathstring–Path to test, default /

No output schema declared.

No examples provided.

scan_domain ~73

Scan a public domain as several crawler identities and return the graded record: grade, AI-visibility score, per-section scores, findings with evidence, and whether the origin refused CrawlCheck. One scan takes 5-15 seconds.

NameTypeReqDescription
domainstringyesA bare domain such as example.com, or a full URL

No output schema declared.

No examples provided.

telemetry ~37

Verified-crawler traffic observed at crawlcheck.io itself: which named agents arrived, how many claims were confirmed against operator ranges, how many were forged.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

verify_crawler_log ~86

Given raw web-server access-log lines, decide for each line that names a crawler (GPTBot, ClaudeBot, Googlebot, PerplexityBot...) whether the source IP falls inside that operator's published ranges. Returns verified, spoofed, or unverifiable when the operator publishes no ranges.

NameTypeReqDescription
linesstringyesUp to 200 raw log lines, newline separated

No output schema declared.

No examples provided.

video_channel ~70

Every upload on a YouTube channel, read 50 at a time, sorted by views. The upload list is free; the per-check tally needs a Watch licence and is not offered here.

NameTypeReqDescription
handlestring–@channel handle
idstring–Channel id, if no handle

No output schema declared.

No examples provided.

video_check ~60

One YouTube video against the video anchor model: metadata, chapters, captions and storyboard where observed, twelve checks each naming what it reads.

NameTypeReqDescription
freshboolean–Bypass the six-hour cache
vstringyesVideo id or URL

No output schema declared.

No examples provided.

video_site ~74

The site half of video: homepage plus up to 60 sitemap pages read for YouTube embeds, facades and page-builder widgets, VideoObject nodes and their required properties, and - with a handle - how many of the channel's videos the site carries.

NameTypeReqDescription
domainstringyes–
handlestring––

No output schema declared.

No examples provided.

Install

How do I install the CrawlCheck MCP server?

CrawlCheck is a hosted endpoint at https://crawlcheck.io/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

remote · crawlcheck.io

# add to Claude Code
claude mcp add --transport http emmanuelorta-crawlcheck 'https://crawlcheck.io/mcp'
Common questions

What is the CrawlCheck MCP server?

CrawlCheck is an MCP server listed in the public MCP registry as io.github.emmanuelorta/crawlcheck. Verification layer for the agentic web: a signed answer about any site before an agent acts. This page covers its hosted endpoint (https://crawlcheck.io/mcp).

Is the CrawlCheck MCP server safe to use?

CrawlCheck scores 81 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

What tools does the CrawlCheck MCP server expose?

CrawlCheck exposes 25 tools: preflight, best_source, resolve_domain, field_check, scan_domain, and 20 more. Their descriptions and schemas cost roughly 2,667 tokens of context every time the server is loaded.

Does the CrawlCheck MCP server require authentication?

No. We connected to CrawlCheck without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

Is the CrawlCheck MCP server still maintained?

CrawlCheck is still listed as active in the MCP registry. We last reached this channel on 4 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.