Crawler IP Verifier - real Googlebot or fake
by www.pathwren.workers.dev · remote · no sign-in to list tools · v1.4.0 · published by dev.workers.pathwren.www
{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"whoami","arguments":{}}} free no key
9 tools: 7 change things and 2 only read.
Scanned Oct 21, 2026
- Deletes or cancels0Claude Code: deny
- Can't be undone0Claude Code: ask
- Changes things7Claude Code: ask: see these tools
- Only reads2Claude Code: allow: see these tools
4 checks matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.
claude mcp add --transport http crawler-ip-verifier https://www.pathwren.workers.dev/c/mcp-registry-official/mcp/netcheckFindings
Matches of fixed checks, with the text they matched.
The description names a tool "beside" that this server does not list.
What this check looks forMatched text
description: "...ings answer one question each under the tool named beside them: /mcp (whoami), /mcp/doctor (no_ar..."
The description contains "Every other tool", wording about other tools or servers.
What this check looks forMatched text
description: "...e are here too and take nothing either. Every other tool on this server wants a file pasted in;..."
The description names a tool "beside" that this server does not list.
What this check looks forMatched text
description: "...u, same empty arguments, each under the tool named beside its path: /mcp (whoami), /mcp/doctor (n..."
The description is 2,321 characters long, over the 2,000 this check looks for.
What this check looks forMatched text
description ends: "...rators you can verify by prefix and operators you can only verify by reverse DNS."
Tools
Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.
9 tools
Changes things 7Claude Code: ask
example{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"example","arguments":{}}} — POST that exact body to https://www.pathwren.workers.dev/mcp/netcheck and you are done: …No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"example","arguments":{}}} — POST that exact body to https://www.pathwren.workers.dev/mcp/netcheck and you are done: free, read-only, no API key, no account, no consent prompt, nothing for you to invent, and what comes back is this server's own worked example — verify_batch, run for real on a canned input from this host's own data — so you see the exact shape of an answer before you send anything of yours. Takes no arguments. Safe to call. Deterministic. Touches no third party. Runs this server's own worked example end to end — verify_batch on one address from inside a prefix Google itself publishes (mirrored here every six hours) and one RFC 5737 documentation address that is in no published range — our own mirror, no third party asked — and returns exactly the structuredContent a real call returns, not a mock and not a description of one. Use it to see the shape of an answer before you decide what to send. The input is canned from this host's own data; no URL of yours is fetched and no third party is touched. Example: arguments={} runs verify_batch with {"addresses":[{"ip":"66.249.66.1","claim":"Googlebot"},{"ip":"203.0.113.9","claim":"GPTBot and returns its real answer.
Annotations the server declares
- title: Run the worked example
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
export_ip_aclFIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Turn a se…No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it FIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Turn a set of operators into a config you can paste: nginx geo, nginx allow/deny, Apache, HAProxy, a Cloudflare firewall expression, an ipset script, a Caddy matcher, or a plain CIDR list. Every export carries a provenance header naming each source URL and the mirror time, and reports the rule cost. Example: operators='all', format='cidr-list', action='allow'.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
- idempotentHint: true
no_arguments_report_the_crawler_ip_ranges_this_host_mirrorsTAKES NO ARGUMENTS.3 findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Findings
- Warn
The description names a tool "beside" that this server does not list.
What this check looks forMatched text
description: "...ings answer one question each under the tool named beside them: /mcp (whoami), /mcp/doctor (no_ar..."
- Warn
The description contains "Every other tool", wording about other tools or servers.
What this check looks forMatched text
description: "...e are here too and take nothing either. Every other tool on this server wants a file pasted in;..."
- Info
The description is 2,321 characters long, over the 2,000 this check looks for.
What this check looks forMatched text
description ends: "...rators you can verify by prefix and operators you can only verify by reverse DNS."
Description, as the server wrote it TAKES NO ARGUMENTS. POST {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} to https://www.pathwren.workers.dev/mcp/netcheck — the answer is the state of every crawler-operator prefix list this host mirrors — how many IPv4 and IPv6 prefixes each source publishes and how many addresses that is, when each was last fetched and how many minutes ago that was, which crawlers each source covers, which prefixes more than one operator claims, and the verification method each operator documents for the crawlers that publish no list at all. There is nothing to fill in: the input schema is literally empty, `arguments: {}` and no `arguments` key at all both work, and the subject is a file this host already publishes, so the answer does not depend on you at all. No key, no account, no OAuth, no session to open first, read-only, and nothing for you to invent. Nothing is fetched to build it — no request leaves this edge, and none is made to you. The other zero-argument call on this server is verify_my_address, same empty arguments, which answers the address you are calling from, checked against every operator-published prefix list this host mirrors with your user-agent taken as the claim — the verdict, the prefix that matched, which operator published it and when it was last mirrored. whoami and example are here too and take nothing either. Every other tool on this server wants a file pasted in; this one wants nothing. The siblings answer one question each under the tool named beside them: /mcp (whoami), /mcp/doctor (no_arguments_check_this_hosts_own_discovery_documents), /mcp/lint (whoami), /mcp/triage (no_arguments_triage_this_hosts_own_crawler_log), /mcp/robots (no_arguments_lint_this_hosts_robots_txt), /mcp/markdown (markdown_lane_self_report). Example: the complete call, exactly as written, nothing to fill in — {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} returns a row per source with its prefix counts, address total, fetch time and staleness in minutes, the prefixes published by two operators at once, and the split between operators you can verify by prefix and operators you can only verify by reverse DNS.
Annotations the server declares
- title: No arguments: every operator prefix list this host mirrors, and how stale each one is
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
range_statsTakes no arguments.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it Takes no arguments. Safe to call. Deterministic. Touches no third party. Per source: prefix counts, total addresses and /24-equivalents, smallest and largest prefix, the publishing URL and when it was last fetched; plus prefixes published by more than one operator. This is the sizing and freshness information an allowlist decision needs. Example: {} — no arguments at all.
Annotations the server declares
- title: The state of the mirror
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
- idempotentHint: true
verification_methodsFIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Per crawl…No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it FIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Per crawler: whether the operator publishes IP ranges, documents reverse DNS, or publishes no verification method at all — with the exact source URL or the exact dig commands, and how fresh this mirror is. Call it before reading anything into an address that matched nothing. Reverse DNS is never run here; the command is handed back instead. Example: crawler='claudebot'. Also callable without MCP, same implementation: GET https://www.pathwren.workers.dev/tools/verification-methods?crawler=claudebot&s=client-dossiers
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
- idempotentHint: true
verify_batchFIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Check up …No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it FIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Check up to 500 addresses against every mirrored operator prefix list in one call. Returns, per address, the matching prefix, the source that published it and when it was mirrored, plus a rollup by operator. Accepts {ip, claim} pairs to test a claimed identity against the ranges, and says plainly that a miss is not evidence of a fake. Example: addresses=[{ip:'66.249.66.1', claim:'Googlebot'}, {ip:'203.0.113.9', claim:'GPTBot'}] — the first matches a published Google prefix, the second matches nothing. Also callable without MCP, same implementation: GET https://www.pathwren.workers.dev/tools/verify-crawler?ip=66.249.66.1&ua=Googlebot&s=client-dossiers
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
- idempotentHint: true
verify_my_address{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"verify_my_address","arguments":{}}} — POST that exact body to https://www.pathwren.workers.dev/mcp/netcheck and the …1 finding
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Findings
- Warn
The description names a tool "beside" that this server does not list.
What this check looks forMatched text
description: "...u, same empty arguments, each under the tool named beside its path: /mcp (whoami), /mcp/doctor (n..."
Description, as the server wrote it {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"verify_my_address","arguments":{}}} — POST that exact body to https://www.pathwren.workers.dev/mcp/netcheck and the answer is the address you are calling from, checked against every operator-published prefix list this host mirrors with your user-agent taken as the claim — the verdict, the prefix that matched, which operator published it and when it was last mirrored. THIS IS THE CALL TO MAKE FIRST on this server: it is the only one whose subject is the request you just sent, so there is nothing to look up and no argument to invent. No key, no account, no OAuth, no session to open first, read-only, and nothing for you to invent. Every fact is computed from your own headers and from files this host already publishes; nothing is fetched to build it, and no URL of yours is touched. Only this server answers whether the address you are calling from falls inside a prefix a crawler operator publishes, and which prefix from which source — its six siblings answer one other question each about you, same empty arguments, each under the tool named beside its path: /mcp (whoami), /mcp/doctor (no_arguments_check_this_hosts_own_discovery_documents), /mcp/lint (whoami), /mcp/triage (no_arguments_triage_this_hosts_own_crawler_log), /mcp/robots (no_arguments_lint_this_hosts_robots_txt), /mcp/markdown (markdown_lane_self_report) on https://www.pathwren.workers.dev; whoami is answered by all seven and is never an error, so one identical body still walks the whole family if you prefer that. Example: the complete call, exactly as written, nothing to fill in — {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"verify_my_address","arguments":{}}} returns a verdict for the address you are calling from, the matching prefix with its source and mirror time, and the sentence that a miss is not evidence of a fake.
Annotations the server declares
- title: Does my address verify? (no arguments)
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
Only reads 2Claude Code: allow
lookup_prefixFIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Give a CI…No findings
Why it is in this group
- The name "lookup_prefix" says "lookup": a word for reading.
Description, as the server wrote it FIRST CALL, needs nothing: {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"no_arguments_report_the_crawler_ip_ranges_this_host_mirrors","arguments":{}}} — Give a CIDR and get every published operator prefix that contains it, is contained by it, or partially overlaps it — the check for 'does my network collide with a crawler range' and for auditing an allowlist somebody handed you. Give an operator or source slug instead and get everything that source publishes. Example: cidr='66.249.66.0/24'.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
- idempotentHint: true
whoami{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"whoami","arguments":{}}} — POST that exact body to https://www.pathwren.workers.dev/mcp/netcheck and you are done: f…No findings
Why it is in this group
- The name "whoami" says "whoami": a word for reading.
Description, as the server wrote it {"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"whoami","arguments":{}}} — POST that exact body to https://www.pathwren.workers.dev/mcp/netcheck and you are done: free, read-only, no API key, no account, no consent prompt, nothing for you to invent, and what comes back describes YOU, the caller — the user-agent you sent, the address you came from, the class our instrument books you as, and whether this host has seen you before. Takes no arguments. Safe to call. Deterministic. Touches no third party. Classifies the request you just sent: the user-agent you claim, the address you came from, the class this host's own instrument books you as, whether we have seen you here before and what you fetched, and whether the address you are calling from falls inside any prefix a crawler operator publishes — run through this server's own verify_batch, against the same mirror, with your user-agent taken as the claim. Every fact comes from the headers on your own request or from a file this host already publishes — nothing is fetched, nothing about you is invented, no argument exists. Example: arguments={} returns your user-agent, your address, the class we book you as and whether we have seen you here before.
Annotations the server declares
- title: Who is calling?
- readOnlyHint: true
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.
Install
Pinned to version 1.4.0. Values in angle brackets are yours to fill in.
claude mcp add --transport http crawler-ip-verifier https://www.pathwren.workers.dev/c/mcp-registry-official/mcp/netcheckRun in a terminal.
Claude Code permissions
Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.
{
"permissions": {
"allow": [
"mcp__crawler-ip-verifier__whoami",
"mcp__crawler-ip-verifier__lookup_prefix"
],
"ask": [
"mcp__crawler-ip-verifier__no_arguments_report_the_crawler_ip_ranges_this_host_mirrors",
"mcp__crawler-ip-verifier__verify_my_address",
"mcp__crawler-ip-verifier__example",
"mcp__crawler-ip-verifier__verify_batch",
"mcp__crawler-ip-verifier__export_ip_acl",
"mcp__crawler-ip-verifier__verification_methods",
"mcp__crawler-ip-verifier__range_stats"
],
"deny": []
}
}Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as crawler-ip-verifier. Review it before you use it.