Stateless Streamable HTTP MCP

JSON-RPC via official MCP transport. tools/list is the authoritative input contract. Provider archive references and file parameter metadata are advertised only when provider downloads are configured; otherwise use files or archive_base64. Unknown mutation input fields are rejected. create/update/delete prepare only; the user must open approval_url. No management tokens or model-supplied source IPs. JSON body <=70 MiB; decoded ZIP <=50 MiB; inline static bytes <=1 MiB.