Test: MCP streamable HTTP transport

[connor4312]

Refs: #244751

• anyOS @jrieken
• anyOS @pierceboggan

Complexity: 4

Create Issue

---

This iteration we've adopted the latest "streamable HTTP" spec for MCP server. Please test this using two different MCP SDKs. This new transport supplants the old "SSE" transport, but VS Code supports both and falls back to SSE if Streamable HTTP fails.

Record your SDK choice here so the other tester doesn't use the same one:

• tester1: dotnet, ts
• tester2:

The SDK's all include example servers as part of this repo. Please:

1. Look through the SDK and find an example server that uses HTTP or SSE.

2. Start it, and configure it in your workspace or global MCP configuration. You should have a server like "my-server": { "url": "http://localhost:3001/sse" } for example

3. Run MCP: List Servers command, the MCP: Start Server. It should then show output and say it Discovered X tools after it successfully connects. There should be no surprising errors. If you used SSE, then you should see a message about "falling back to SSE".

4. Now, swap transports. If you used an SSE example, please find a Streamable HTTP example, and vise versa. You may need to go back to an older SDK revision if SSE was removed from your chosen implementation (though I think most SDKs currently have both.)