I switched from macports to homebrew a decade ago. I needed the lastest version of a program, and I found homebrew updated formulas faster than macports did
The prose on the page is very unclear. My best interpretation is that they want to continue supporting stdio but that they don’t want it to be its own special protocol. The obvious way to do that would be to speak ordinary HTTP (version 1.1? 2?) over stdio and to use the MCP-over-HTTP protocol over the resulting HTTP transport.
This would be more complex to implement for a simple server, but it’s not exactly difficult.
I’m not really a fan. But if you’re building a protocol that needs to map to HTTP anyway, then maybe using the HTTP binding everywhere is not totally awful.
In the flip side: I’m currently designing an AI-adjacent protocol, and it will be able to map to WebTransport, but I don’t plan to define non-WebTransport HTTP bindings unless a very compelling reason appears. The main implementations will not use HTTP at all :)
> if you’re building a protocol that needs to map to HTTP anyway
I don't think there is any guarantee that HTTP will always be involved. For example I might be calling a local LLM via CLI/script on a server with a stdio MCP connector that just runs other CLI commands, and never sends any HTTP traffic.
Right. But there is a lot of real-world usage of MCP-over-HTTP-over-the-Internet, and a lot of “harnesses” want to support that use case, so they’re stuck either implementing the HTTP-based protocol or using a shim.
1. We already use it plenty, so we have lots of implementations,
2. it's good enough.
Cons:
a. what shall be the form of HTTP IPC URIs? hostnames for http: and https: scheme URIs are kinda out of place in IPC applications (we need something like sys.ipc.arpa, d-bus.arpa, etc),
b. the overhead of HTTP is annoying -- any decent RPC can be significantly more efficient, unless one uses HTTP/2, and maybe even then.
(a) makes me want to write and submit an I-D for HTTP over IPC by using such names as in the parenthetical above.
Those are mostly at a different layer. You can speak Thrift or Avro or Protobuf over stdio or HTTP or TCP or carrier pigeon.
gRPC spans layers, and it uses HTTP in a more intrusive way than even MCP does — it expects to own the entire URL space at the IP/port in question. Using gRPC in a nontrivial way for MCP would be fairly heavy-weight: you would probably need to set up reflection and figure out how to bind all the MCP calls to it unless you just use it as a tunnel.
It was closed yesterday as "completed" by Anthropic's bcherny, despite not being implemented/completed, and being by far the most requested feature that would take all of 10 seconds to implement. So yes, something happened yesterday.
This issue was linked in the recently-front-page issue on Opus 5 using astronomically hard to understand manners of speaking. Someone must have just noticed it and decided to post it here.
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