[dend]

Hey folks - one of the Lead Maintainers for MCP. Happy that we got this release out the door today, this is an exciting change for those that wanted to roll out remove MCP servers into serverless hosts. There is, of course, more good stuff packed, so if you have questions or feedback - our team is here to help!

[jakobgm]

Congrats at shipping the new specification!

Any new to share on file upload support? We have shipped a MCP server and it has been really frustrating to observe MCP clients fumbling around with base64-encodings, polluting their context window with binary data. SEP-1306 (Binary Mode Elicitation) was superseded by SEP-2356 (File input support for tools and elicitation), and that was in turn superseded by SEP-2631 (File Objects and Transfer) which is currently left in a draft state with little activity.

Allowing LLM-based agents to shuffle binary data around efficiently and reliably seems like a pretty big gap in the current specification, if you ask me!

[colinator]

I concur. Most of my MCP pain is dealing with client's differing ability to handle images. Some clients (old codex) would even truncate the base64 data regardless of how it was json-wrapped. And sometimes they just ingest the base64 date directly into their context window. Not sure if this is an MCP thing or a clients-poorly-implementing-MCP thing.

[somnium_sn]

Hey I am the one Lead maintainer of the MCP protocol.

I agree and hear you that file uploads are a pain. As the core maintainer group we have deferred the work on this for this release and hope to pick it up soon.

Now is the moment to engage with the respective working group to make your case heard so we can ensure it’s on the roadmap.

[checker]

Thank you for your work! I was looking forward to the stateless update.

[dan-kwiat]

Great work! Any word on when to expect support across claude clients?

[dend]

We are actively working on this - the support is rolling out across the ecosystem: https://claude.com/blog/bringing-mcp-2026-07-28-to-claude

[cidd]

When will java sdk come out with latest changes from spec?

[somnium_sn]

The Java SDK is currently a Tier 2 SDK.. As a Tier 2 SDK they have up to 6 months to implement it. I know they are actively working towards support for the specification.

Best to join our community discord [1] and ask the maintainers !

[1] https://modelcontextprotocol.io/community/communication

[Oras]

Thank you!

What’s the best practice for tools where the upstream API only supports basic auth (username/password) and there’s no OBO option? In my case the login returns a token that’s only valid for an hour, so the user has to re-auth after that. Do you stash the credentials on the MCP server and silently refresh, or is there a nicer pattern people are using?

[dan-kwiat]

URL Elicitation works well if a human is driving the client. Unfortunately MCP client support is patchy but I expect that will change now the protocol is stateless.