{"version":"2.1.285","anchor":"mcp-discovery-cache-for-ccr-dynamic-http-servers","canonical_anchor":"mcp-discovery-cache-for-ccr-dynamic-http-servers","heading":"MCP discovery cache now limited to dynamic toolbox servers in cloud sessions","tier":"internal","area":"MCP","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.285\/e\/mcp-discovery-cache-for-ccr-dynamic-http-servers","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.285","markdown":"### MCP discovery cache now limited to dynamic toolbox servers in cloud sessions\n\nWith `MCP_DISCOVERY_CACHE` on, only dynamic toolbox HTTP servers in cloud sessions that send two identifying headers can use the cache\n\n**What**\n\nClaude Code now checks each HTTP MCP server to decide whether it may use the discovery cache. MCP servers are outside programs that give Claude Code extra tools. A server qualifies only when all of these are true:\n\n- `MCP_DISCOVERY_CACHE` is set to true\n\n- the server is a dynamic toolbox server in a Claude Code cloud session\n\n- the server sends both the `x-mcp-server-id` and `x-mcp-server-origin` headers\n\nAny other server is treated as relying on ambient credentials, meaning sign-in details picked up from the surrounding environment, and does not qualify.\n\n**Why**\n\nThis only matters in cloud sessions where `MCP_DISCOVERY_CACHE` is set. Everywhere else, the cache is not used for HTTP servers.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 3\/5"}