{"slug":"pearson-correlation-31872c24","name":"Pearson correlation","summary":"Pearson correlation coefficient and covariance of two equal-length paired series. Rejected as a clean 400 if the lengths differ or either series has zero variance (correlation undefined).","status":"live","indexable":true,"listed_since":"2026-10-25T17:53:06.921260Z","sources":[{"source":"x402_bazaar","external_id":"https://stats.openverbs.com/v1/correlation","owner_address":"0xb3f4de103f34b99f0da19b4f16d6b53a14c2194a","seen_at":"2026-11-02T19:15:29.965314Z","removed_at":null}],"endpoints":[{"url":"https://stats.openverbs.com/v1/correlation","host":"stats.openverbs.com","protocol":"x402","state":"live","last_probe_at":"2026-11-03T00:20:07.313610Z","last_ok_at":"2026-11-03T00:20:07.313610Z","tools_count":null,"tools_changed_at":null,"uptime_24h":1.0,"uptime_30d":1.0}],"also_listed_as":[{"slug":"stats-openverbs-com-8bb0404b","name":"stats.openverbs.com"}],"payment_options":[{"endpoint_url":"https://stats.openverbs.com/v1/correlation","network":"eip155:8453","scheme":"exact","rail":"exact","asset":"0x833589fcd6edb6e08f4c7c32d4f71b54bda02913","coin":"USDC","asset_label":"USD Coin","amount":"4000","pay_to":"0xb3f4de103f34b99f0da19b4f16d6b53a14c2194a","observed_at":"2026-11-03T00:20:07.313610Z"}],"usage":{"source":"x402_bazaar","unique_payers_30d":2,"paid_calls_30d":2,"last_paid_at":"2026-10-08T05:38:33.231Z","reported_at":"2026-11-02T19:15:29.965314Z"},"assessment":{"method":"2026.10.2","checks":[{"id":"answers","state":"pass","reason":"Answered a check within the last hour."},{"id":"owner","state":"fail","reason":"No one has proven control of its domain or of the wallet it is paid at."},{"id":"track_record","state":"fail","reason":"Listed for 8 days; 30 are needed."},{"id":"real_customers","state":"fail","reason":"2 different wallets paid it in 30 days, as the x402 Bazaar reports (not yet counted by addrbook); 10 are needed."},{"id":"clean_scan","state":"not_applicable","reason":"Not an MCP server."}],"passed":1,"applicable":4,"contradicted":false,"computed_at":"2026-11-03T00:44:00.118583Z"},"identity":{"endpoint_domains":["openverbs.com"],"proven_domains":[],"proven_wallets":[],"namesakes":[],"namesake_count":0,"identity_checks":[],"wallet_attestations":[],"human_backings":[]},"replies":[],"customers":null,"scan":null,"notice":"Not affiliated with addrbook — claim or request removal."}