Support "Streamable HTTP" transport

[taobaorun]

(Original content)
Expected Behavior

The "Streamable HTTP" transport is a fantastic feature, particularly beneficial for stateless MCP servers and remote MCP servers in distributed scenarios. It enables MCP to be swiftly employed in production-grade agent applications

Current Behavior

The issue with the current session is that it needs to support distributed sessions.

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(Edit by @chemicL follows)

To split the task, what needs to happen to consider it done:

Steps

• Reviewing the Spec and introducing architectural changes required for the client side aiming for backwards compatibility if possible (WebClient Streamable HTTP support #292)
• Implementing JDK HTTP Client support (feat: implement HttpClient Streamable HTTP transport #337)
• Implementing WebClient Client support (WebClient Streamable HTTP support #292)
• Reviewing the Spec and introducing architectural changes required for the server side aiming for backwards compatibility if possible and allowing both stateful and stateless servers
• Implementing Servlet Server support
• Implementing Spring WebMVC Server support
• Implementing Spring WebFlux Server support

[lambochen]

When is 2025-03-26 Implementation 's release date? thx @chemicL

[dyrnq]

stare

[Pratiush]

I would love to contribute on this feature.

[chemicL]

I started diving into the subject and began prototyping it. If there arise some areas where contributions will be useful, I will update this issue with links to individual tasks. Thanks for your patience.

[chemicL]

Folks, feel free to test locally the work in progress in #292 and please report any issues. We will follow up with the JDK HttpClient implementation and then take care of the server side.