{"@context":"https://schema.org","@type":"Dataset","name":"MCP Registry Runtime Liveness Census","description":"Independent runtime liveness census of the official Model Context Protocol registry population. On 2026-06-10, of 1456 probed registry servers (out of 4914 with a remote endpoint), 509 answered an anonymous MCP initialize handshake, 507 were alive but auth-gated, and 82 were unreachable.","url":"https://dominion-observatory.sgdata.workers.dev/atlas/census","creator":{"@type":"Organization","name":"Dominion Observatory","url":"https://dominion-observatory.sgdata.workers.dev"},"isAccessibleForFree":true,"dateModified":"2026-06-10","measurementTechnique":"Anonymous MCP `initialize` JSON-RPC handshake over each registry-listed remote endpoint; responses categorized without conflating auth-gated (401/403) with dead.","variableMeasured":[{"@type":"PropertyValue","name":"registry_servers_total","value":11529},{"@type":"PropertyValue","name":"with_remote_endpoint","value":4914},{"@type":"PropertyValue","name":"probed","value":1456},{"@type":"PropertyValue","name":"handshake_ok","value":509},{"@type":"PropertyValue","name":"auth_gated","value":507},{"@type":"PropertyValue","name":"unreachable","value":82}],"provenance":{"row_hash":"dbdef6dd618b526b5aaf5f067b3ba39d9807a7e511c9a29e851b95af27513d1b","prev_hash":"GENESIS","hash_alg":"SHA-256","note":"Hash-chained across runs for tamper-evidence."}}