MCP roots, sampling and logging deprecated: Sume impact

If you call Sume's hosted MCP server, deprecating Roots, Sampling and Logging changes nothing you have to do. Sume's initialize answer declares only a tools capability, and the server code has no method that asks the client for roots, sampling or logging. What you send Sume goes in tool parameters, which is the migration the spec itself suggests.

The deprecation is from the MCP project's 2026-07-28 key changes, read 2026-09-29. The Sume side is the hosted server code and the MCP tools and gates page.

What did the spec deprecate?

The changelog lists a deprecation of the Roots, Sampling and Logging features. It says they "remain fully functional during the deprecation window" but new implementations should not add support for them.

What does Sume's server declare?

In the hosted server's initialize result, capabilities holds tools with listChanged set to false and nothing else. Roots and Sampling are capabilities a client offers a server, and Logging is one a server offers; Sume advertises none of them.

A client that ignores or drops those features loses nothing when it talks to Sume. The tool calls still carry what Sume needs, such as prompts and public URLs.

Where do my inputs go instead of roots?

Into the tool arguments. The docs' playbook is: call a tool with dry_run=true, review the preview, repeat without dry_run to submit, poll with jobs_status or jobs_wait, then read jobs_result. Every input is an argument on that call, so there is no directory scope for a client to declare.

Files are the one place roots might have seemed useful, and the docs close that door: "Hosted MCP cannot read files from your laptop." The upload flow is to create an upload URL with assets_upload_url, have the client PUT the bytes, then call assets_complete. The client, not the server, moves the file, so no root is needed to say where it lives. Both tools are write tools and take an idempotency_key.

What about the new request pattern?

The same revision replaces server-initiated requests such as roots/list, sampling/createMessage and elicitation/create with Multi Round-Trip Requests: the server returns an input_required result and the client retries with inputResponses. Sume's tool calls do not ask for input mid-call, so a client can treat every tools/call result as final for that call.

The same changelog also reclassifies the HTTP+SSE transport as deprecated and points to Streamable HTTP. Sume's endpoint is a POST JSON-RPC endpoint; a GET to it answers 405 with "Remote MCP uses POST JSON-RPC requests." Point new clients at https://mcp.sume.com/mcp as a streamable HTTP server.