AI Crawler Index

Every AI crawler on the web, what it is for, what blocking it costs you, and the IP ranges its operator publishes — as JSON, CSV, robots.txt and regex. Ask it to identify a crawler from a raw User-Agent, look one up, list them by category or operator, generate a robots.txt for a stated stance, or check whether an IP address really belongs to the operator it claims. Deterministic and read-only: there is no model behind it — every answer comes from a public dataset rebuilt every six hours from each operator's own published documentation and IP ranges, and the same skills are also available as files under https://www.pathwren.workers.dev/ and as MCP tools at https://www.pathwren.workers.dev/mcp. No key, no signup, no quota. Independent and unaffiliated with any operator it documents. TO CALL IT: send `message/send` (v1.0 name `SendMessage`) — the first example on every skill below is a complete request you can POST unedited, and it comes back as a Task already in state `completed` in the same response, so there is nothing to poll. Nothing to hand over? The `whoami` skill takes no arguments and answers about you. Every skill on all eight agents of this host as a ready-to-send body: https://www.pathwren.workers.dev/a2a/example.json

Skills

• Classify a user-agent string
  Identify the crawler behind a raw User-Agent header: operator, category, robots.txt stance, how to verify it, and what blocking it costs. A user-agent is a claim, not proof — confirm with is_verified_crawler_ip. Example: user_agent='GPTBot/1.2' returns GPTBot, OpenAI, ai-training. Also callable without MCP, same implementation: GET https://www.pathwren.workers.dev/tools/classify-ua?ua=GPTBot%2F1.2&s=client-dossiers
  user-agentcrawlersbot detectionidentification
• Look up one crawler
  The full index record for one crawler: operator, category, robots.txt token and stance, user-agent substring and example, verification method, mirrored IP-range endpoint, and what blocking it costs. An unknown slug returns near matches. Example: slug='claudebot'.
  crawlersreferencerobots.txtlookup
• List and filter crawlers
  The index, filtered or whole: each row says what the crawler is and what blocking it costs, and the reply lists every valid filter value. Example: category='ai-training', limit=20.
  crawlerscataloguefilterdiscovery
• Generate a robots.txt for a stance
  A ready-to-paste robots.txt block for one stance, with the reasoning and the crawlers it names. Omit the argument to get all eight stances described. Example: stance='block-ai-training'.
  robots.txtpolicyconfigurationgenerator
• Check an IP against operator-published crawler ranges
  Test an IPv4 or IPv6 address against every crawler prefix the operators themselves publish, remirrored every six hours. Returns the matching prefix, its source and the crawlers using it; a miss is reported as a miss, not as a forgery. Example: ip='20.171.206.5'. Also callable without MCP, same implementation: GET https://www.pathwren.workers.dev/tools/verify-crawler?ip=20.171.206.5&s=client-dossiers
  ip rangesverificationbot detectionsecurity
• What changed in the index
  Freshness and change state: when the index was built, when each operator source was last fetched, which changed, which are failing, and the dated changelog. The cron check before regenerating a config from this data. Example: since='2026-08-01'.
  freshnesschangelogmonitoringdata quality
• What changed since your cursor
  Only what changed since your last call: prefixes added or removed, upstreams failed or recovered, records edited. Send back the `cursor` from the previous result; it advances only on a real change, and the data refreshes every 6h. Example: since='0'.
  changelogmonitoringpollingincremental sync
• Who is calling? (no arguments)
  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 what this host's robots policy says about you. 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.
  identifyno argumentsdiagnosticsuser-agent
• Run this server's worked example (no arguments)
  Takes no arguments. Safe to call. Deterministic. Touches no third party. Runs this server's own worked example end to end — one of its real tools, on a canned input taken from this host's own published data — 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. No URL of yours is fetched and no third party is touched. Example: arguments={} runs it and returns the real answer.
  exampleno argumentsdemogetting started

How to call

https://www.pathwren.workers.dev/a2a

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