The everything-server returned its -32602 missing-_meta rejection with
HTTP 200; the draft spec requires 400 Bad Request. It also applied the
per-request _meta validation to sessionless requests carrying a legacy
session-era version header, although per-request metadata is a
2026-07-28 requirement; such requests now fall through to the session
path.
The server-stateless scenario gains a companion check
(sep-2575-http-server-meta-invalid-400) requiring HTTP 400 on those
rejections, and sep-2575-server-unsupported-version-error now also
requires error.data.requested to echo the requested version. Two new
negative tests pin both.