When is 2025-11-25 protocol version support expected?

[devwhodevs]

Problem

Downstream MCP servers built with rmcp cannot surface tools in Claude Desktop's Cowork and Code modes because these modes require protocolVersion: "2025-11-25", but rmcp 1.4.0 only supports up to "2025-06-18".

The MCP handshake completes successfully — the client proceeds through initialize → notifications/initialized → tools/list — and all 22 tools work in standard Claude Desktop chat and Claude Code CLI. But Cowork and Code-in-Desktop apply a stricter version filter and silently exclude servers negotiating older protocol versions.

Evidence

I maintain engraph, a Rust MCP server built on rmcp. A user reported this in devwhodevs/engraph#20 with full MCP logs showing:

1. Client requests protocolVersion: "2025-11-25"
2. Server (rmcp 1.4.0) responds with "2025-06-18"
3. Handshake completes, tools listed, connection stays alive
4. Tools work in standard chat — but not in Cowork or Code modes

Other MCP servers (TypeScript-based) negotiate "2025-11-25" and their tools appear in all modes.

Current state in rmcp

// model.rs (main branch)
pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
pub const LATEST: Self = Self::V_2025_06_18;

I see the 2025-11-25 Implementation project board tracks 18 rust-sdk items, and many SEPs have been merged. Only 3 SEP issues remain open (#526, #531, #527).

Question

Is there a rough timeline for when rmcp will declare 2025-11-25 protocol support? This is currently the only thing blocking Rust-based MCP servers from working in Claude Desktop's newer modes.

Not asking for a commitment — just trying to understand if it's weeks away or months, so downstream projects can plan accordingly.

[DaleSeo]

Thanks for bringing this up, @devwhodevs! I don't think those SEPs are blocking us from supporting 2025-11-25 since they're all optional extensions or future proposals. I've created PR #802 to add support for the protocol version.

@alexhancock @jamadeo Would it be okay if I remove the remaining open SEPs from the implementation project board? I don't see the same SEPs for the other SDKs, and I'm not sure how they were added in the first place.