Crawler IP Verifier vs MCP Endpoint Lint handshake, tool schemas, JSON RPC errors

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no_arguments_report_the_crawler_ip_ranges_this_host_mirrors

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.

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 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.

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: 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.

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: 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.

verify_batch

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

lookup_prefix

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'.

export_ip_acl

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'.

verification_methods

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

range_stats

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.

whoami

{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"whoami","arguments":{}}} — POST that to https://www.pathwren.workers.dev/mcp/lint and the answer is the user-agent you sent, the class this host's own instrument books it as, whether we have logged you here before — and the part only this server can answer: your own client's record on this host, surface by surface, with the status codes it took, plus exactly what this server would do with a URL you handed it (which hosts it refuses, what it identifies itself as, the timeout and the rate limit). Takes no arguments. Safe to call. Deterministic. Touches no third party. Nothing is fetched to build it: every fact comes from the headers on your own request or from a file this host already publishes. Only this server answers the last part — its five 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/triage (no_arguments_triage_this_hosts_own_crawler_log), /mcp/robots (no_arguments_lint_this_hosts_robots_txt), /mcp/netcheck (no_arguments_report_the_crawler_ip_ranges_this_host_mirrors), /mcp/markdown (markdown_lane_self_report) on https://www.pathwren.workers.dev. Example: arguments={} returns your user-agent, your address, the class we book you as, whether we have seen you here before, and your own client's record on this host — every surface of ours your user-agent has been seen on, with the status codes it took.

example

{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"example","arguments":{}}} — POST that exact body to https://www.pathwren.workers.dev/mcp/lint 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 — score_card, 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 — score_card on this server's built-in fixture — an in-process MCP endpoint with one real defect wired in per check (it ignores the protocol version you ask for, refuses a second initialize, publishes a tool whose `required` names a property that does not exist, and answers an unknown method with an HTML 500). No outbound request is made and no third party is touched — 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 score_card with {"url":"fixture://mcp-endpoint-lint/demo"} and returns its real answer.