{"version":"2.1.259","anchor":"mcp-connect-cachingrejecting-the-v1mcp-servers-discover","canonical_anchor":"mcp-connect-cachingrejecting-the-v1mcp-servers-discover","heading":"MCP connect: caching\/rejecting the \/v1\/mcp_servers discover projection","tier":"internal","area":"MCP","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.259\/e\/mcp-connect-cachingrejecting-the-v1mcp-servers-discover","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.259","markdown":"### MCP connect: caching\/rejecting the \/v1\/mcp_servers discover projection\n\nMCP connections can cache a discovery projection to skip a round trip, discarding and re-probing it if the server rejects it.\n\nFor claude.ai-proxy MCP connections, the client can now cache and adopt a \"discover projection\" from `\/v1\/mcp_servers`, skipping the `server\/discover` round trip on connect. If the upstream later rejects a request built from that cached projection, the client discards it for that connector, re-probes `server\/discover` on a fresh transport, and logs a `tengu_mcp_listing_prior_rejected` event.\n\n- Area: MCP\n- Names: `tengu_mcp_listing_prior_rejected`\n- Tier: Under the hood\n- Useful: 3\/5\n- Signal: 4\/5"}