Streamable HTTP transport for remote agents

[parubets]

Any chance we can have support for Streamable HTTP transport?
I would like to just enter the URL endpoint for my agent API backend and the api-key.
Would be super powerful addition to stdio transport.

[benbrandt]

@parubets thanks for the input! We prioritized stdio at the moment because most clients are embedding terminal agents as a subprocess, but we would love to add HTTP support in the future. We worked hard to make sure we weren't doing anything in the protocol that would inhibit this move in the future. We just prioritized stdio for the initial release.