Multi round-trip request (MRTR)

Multi round-trip request (MRTR): The 2026-07-28 pattern where a server returns input_required and the client retries the request with the answers. Example: It replaces server-initiated requests such as elicitation/create. Next in the glossary is Namespace verification: Proof that a publisher controls a registry name, by GitHub login or OIDC for io.github names and DNS or HTTP for domains.

Definition

The 2026-07-28 pattern where a server returns input_required and the client retries the request with the answers.

Example, with source

It replaces server-initiated requests such as elicitation/create. (modelcontextprotocol.io, read 4 November 2026)

Neighbouring terms

• Model Context Protocol (MCP): A JSON-RPC 2.0 protocol in which hosts run clients that connect to servers offering tools, resources and prompts.
• Namespace verification: Proof that a publisher controls a registry name, by GitHub login or OIDC for io.github names and DNS or HTTP for domains.
• NLWeb: Microsoft's open project giving sites a natural-language ask method with Schema.org JSON responses; each instance is an MCP server.