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'@modelcontextprotocol/server': patch
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`ctx.mcpReq.log()` now emits its `notifications/message` notification request-related (like progress and `ctx.mcpReq.notify`), so handler-emitted log messages are delivered when the server is hosted per request via `createMcpHandler` instead of being silently dropped. On a 2026-07-28 request the level filter consults the per-request `_meta` `io.modelcontextprotocol/logLevel` key (the modern equivalent of `logging/setLevel`); per the spec, an absent key means no `notifications/message` is sent for that request.

**2025-era delivery-channel change (spec-conformance correction).** On a 2025-era sessionful Streamable HTTP transport, handler-emitted log messages now ride the per-request POST response stream instead of the standalone GET stream. This is a correction to the 2025-11-25 specification: `docs/specification/2025-11-25/basic/transports.mdx` §"Sending Messages to the Server" item 6 says JSON-RPC messages on the POST response stream SHOULD relate to the originating client request, and §"Listening for Messages from the Server" item 4 says messages on the GET stream SHOULD be unrelated to any concurrently-running client request — so a log emitted from a handler context belongs on the POST stream. Clients reading handler logs off the standalone GET stream will now see them on the per-request POST stream instead. The eventStore-resumable case (a log emitted after `closeSSE()` while the client has not yet reconnected) is handled by the store-first persistence behavior in `WebStandardStreamableHTTPServerTransport.send()`. The session-scoped `Server.sendLoggingMessage()` API is unchanged.