Michael Warres

@PiotrSikora and/or @mathetake , I've finished my pass--this now awaits your approval.

The `on_http_response_headers` callback should already give clear signal as to whether or not a body is expected, via the `end_of_stream` bool param. If `end_of_stream` == true, then the plugin shouldn't...

You might also consider adding a test case to [ext_proc_integration_test.cc](https://github.com/envoyproxy/envoy/blob/main/test/extensions/filters/http/ext_proc/ext_proc_integration_test.cc) similar to [ExtProcIntegrationTest.ResponseMessageTimeout](https://github.com/envoyproxy/envoy/blob/0a2aca4729a853d107ec7e2b89a557ba45aa16a8/test/extensions/filters/http/ext_proc/ext_proc_integration_test.cc#L1203), but with the added element that the downstream disconnects before time is advanced.

Looks like there's a MacOS build issue and Windows msvc_not_found with the updated runners, working on addressing those.

Great--thanks for the tip @rahulchaphalkar! I've been sidetracked by a few other work items this week but will get back to this this weekend.

Interesting--I wonder if it's always been that way? `sha256sum` doesn't exist on MacOS (e.g. https://github.com/ESGF/esg-search/issues/84), but can be done via `shasum -a 256`.

Rerunning the CI

> The failures seem to be due to bazel being unable to find msvc tools. Perhaps simply installing the 2022 tools on the system would be sufficient. That might not...

> Also, I believe that @mpwarres and @martijneken are currently working on the documentation for the whole SDK, so it might be worth waiting a bit for it for the...

It's encouraging to see the eagerness to move the ABI and project as a whole forward! A few responses to some of the questions and comments above. @mathetake [asked](https://github.com/proxy-wasm/spec/issues/41#issuecomment-1586358254): >...