[alies-dev]

Context

Since the playground redesign (#143), /check feels slower. From outside, <?php echo 1; takes 2 to 8 s to answer, while the same request takes about 0.45 s locally, with either the Psalm commit before the deploy or the one now in production. Without server access there is no way to tell whether that time goes to Psalm, to PHP startup, or to waiting before PHP runs at all.

Refs #0

Solution

/check now sends Server-Timing: boot;dur=…, analysis;dur=…, total;dur=… (milliseconds) on successful responses, shown in the DevTools Network tab under Timing:

• boot: from REQUEST_TIME_FLOAT to the start of the analysis (autoload, input checks)
• analysis: OnlineChecker::getResults(), or the cached homepage example
• total: from REQUEST_TIME_FLOAT to just before the body is sent

If the browser's waiting time is much longer than total, the delay happens before PHP starts handling the request (Apache workers, CPU contention, network), not in Psalm.

The header carries only durations: no versions, paths or hostnames. No Timing-Allow-Origin is sent, so other origins cannot read the values. Error responses (400, 418, 422 and exceptions) do not get the header.