A handler behind express.json() is reached from the request stream's 'end'
event, long after the correlation middleware returned, so it looked as if
every write lost its id. It does not: raw-body and multer bind their
callbacks with AsyncResource at the point they are called, which is inside
the request's correlation. Nothing tested that, though, because every
REQID case was a GET. REQID-007 posts a JSON body and REQID-008 one that
arrives in several chunks, and both expect the handler to see the id the
response carries. The middleware comment now says why this holds.
A 5xx stack and its access-log line were two unrelated lines, the
exception filter printed the stack with console.error and no request
context, and the MCP, WebSocket, plugin RPC and cron entry points logged
nothing per call. A self-hosted bug report could not be traced from a
failure back to the call that caused it.
Every HTTP request now runs under an id held in AsyncLocalStorage: a
well-formed incoming X-Request-Id is kept, anything else is replaced by a
UUID, and the response carries it in X-Request-Id. The logger tags every
line written inside a unit of work with `[http <id>]`. The exception
filter leaves a server-side failure on res.locals and the access log
writes the request line and the stack as one entry under that id; without
an access log watching the response it still prints the error itself.
MCP tool, resource and prompt calls (through a new `around` seam on the
registry), WebSocket messages, plugin RPC dispatches and cron ticks each
run through traceEntry(), which gives the call its own id (remembering the
outer one as its parent) and logs one line for it: debug on success, like
the HTTP access log, and warn or error with the reason on failure. The
call's result and timing are unchanged, a failed cron tick is logged once
rather than twice, and a WebSocket handler rejection no longer reaches
rxjs's asynchronous rethrow.
Maurice