About the MCP Registry change history

A public, read-only change history of remote MCP servers listed in the official MCP Registry (registry.modelcontextprotocol.io). For each server ToolFit records what its tools/list returned and what changed since the previous listing: tools added or removed, description and parameter changes, and the ToolFit grade over time.

The crawler sends only initialize, notifications/initialized and tools/list (it never calls a tool), identifies itself as YourAITools-ToolFit, honors robots.txt, waits at least 60 seconds between visits to the same host (at most 50 per host per day), works within a daily budget, and skips servers that need sign-in or payment, URLs with templates or query strings, and private or non-public hosts.

Entries describe changes in tool definitions. They are not statements about a server, its quality or its author. The grade measures how the tool definitions fit model providers (token cost, schema compatibility, confusable names) as scored by the ToolFit engine at the time of the listing.

Opt out

robots.txt on the server host: "User-agent: YourAITools-ToolFit" + "Disallow: /".
server.json in the MCP Registry: "_meta": {"io.modelcontextprotocol.registry/publisher-provided": {"co.youraitools/toolfit": {"history": "opt-out"}}}.
Response header on initialize: "X-ToolFit-History: opt-out" (X-Robots-Tag: noindex is honored too).
POST https://api.youraitools.co/toolfit/history/opt-out with {"name": "<registry name>"} or {"url": "<server URL>"}: crawling stops and stored history is deleted immediately (limited to 10 requests per address per UTC day; each request is logged with its time and a salted hash of the requesting IP, never the IP itself).
Email hello@youraitools.co.

For server owners

Own a server? ToolFit hosted watch re-checks it every 24 h ($0.25 per 30 days) or 6 h ($0.60) and sends you an HMAC-signed webhook when its tools or grade change: POST https://api.youraitools.co/toolfit/v1/watch.

Crawl status

{
 "registry": {
  "entries_seen_last_full_sync": 49510,
  "without_remote_last_full_sync": 16917,
  "sync_mode": "idle",
  "last_full_sync": "2026-10-24T18:01:47.743Z",
  "last_incremental_sync": null,
  "sync_error": null
 },
 "servers_with_remote": 32593,
 "skipped_static": {
  "blocked_url": 29,
  "needs_auth_header": 2972,
  "registry_deprecated": 293,
  "self": 2,
  "templated_url": 287,
  "url_has_query": 638
 },
 "eligible": 28343,
 "opted_out": 29,
 "crawled_servers": 732,
 "last_result": {
  "auth_required": 218,
  "blocked_url": 36,
  "ok": 277,
  "payment_required": 3,
  "robots_disallow": 137,
  "robots_unavailable": 11,
  "too_large": 4,
  "unreachable": 46
 },
 "with_history": 277,
 "events": {
  "first_seen": 277
 },
 "crawls": {
  "total": 761,
  "today": 761,
  "daily_budget": 2000,
  "by_result": {
   "robots_disallow": 137,
   "auth_required": 218,
   "ok": 277,
   "unreachable": 46,
   "blocked_url": 36,
   "opt_out_header": 29,
   "robots_unavailable": 11,
   "payment_required": 3,
   "too_large": 4
  }
 }
}