Mastra MCP 2.0 is 2026-07-28 only: which line for Sume?
@mastra/mcp 2.0.0 drops the legacy handshake and speaks MCP 2026-07-28 only. The Sume server defaults to 2025-11-25, so pin the version you test.
@mastra/mcp 2.0.0 is rebuilt on the MCP 2026-07-28 revision and removes the legacy handshake. The Sume MCP server's default protocol version in code is 2025-11-25, so I would not assume the two connect: test 2.0.0 against https://mcp.sume.com/mcp before upgrading, and stay on the release you have already verified until that test passes.
Vendor facts are from the Mastra release notes; Sume facts from the MCP server code and the MCP quickstart, read 2026-10-01.
What does the Mastra 2.0 release say?
The release notes (@mastra/core@1.68.0, September 23) describe @mastra/mcp@2.0.0 as a major rewrite: MCP 2026-07-28 only, legacy handshake removed, suspend/resume replacing the elicitation APIs, and several transport and protocol surfaces removed per the MCP v2 migration guide. They also say there is no initialize handshake or session headers in this revision.
What does the Sume server speak?
The server code sets the default to 2025-11-25 and also accepts 2025-03-26 and 2025-06-18. Its initialize response declares tools.listChanged: false, so it does not push tool-list changes, and names itself sume-remote-mcp. Nothing in the code I read lists 2026-07-28.
| Fact | @mastra/mcp 2.0.0 | Sume server code |
|---|---|---|
| Protocol revision | 2026-07-28 only | 2025-11-25 default; 2025-03-26 and 2025-06-18 also accepted |
| Initialize handshake | Removed | Used, returns serverInfo |
| Tool list change push | Not stated | listChanged: false |
Which @mastra/mcp line should I use?
Keep the line you have already verified against Sume, and run a one-tool check on any upgrade: connect, list tools, call mcp_health. The existing walkthrough, Mastra MCP client with Sume, covers the setup. If a 2.0.0 connection fails, record the error text and the version you pinned, and stay on the working release until the Sume server's supported versions change.
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