Feature Request: HTTP headers in xhr breadcrumbs

[k-funk]

On an XHR breadcrumb, I can see the url, status code, and method, but I need HTTP Headers to debug errors. I can fairly easily configure to identify a user when a failure occurs, but not which of their requests.

Adding a dropdown to this row, or even navigating away to a new page would be great.

[mitsuhiko]

@k-funk which headers in particular are relevant for you? Capturing all headers is excessive but maybe we can identify common ones that are interesting.

[k-funk]

In my case, the relevant header is custom, so I'd either need to be able to configure to capture that one, or get all of them.

[benvinegar]

The goal of breadcrumbs is to be lightweight hints, and are intended to be small in size (a few fields, max). We can't add freeform values of potentially unbounded size because we will quickly blow through the (current) 100KB payload limit, which will cause the event to be rejected.

[k-funk]

Any way for me to identify xhr requests defined by my server with that HTTP Header, either by enhancing breadcrumbs or some other way?

[LewisJEllis]

2 avenues that might be relevant:

1. If you know, in some path of your application code, that a particular request you're dealing with might have that http header of interest, you could manually capture a generic breadcrumb in that codepath. Not ideal/automatic/all-encompassing, but is simple and could be passable depending on your use case.

2. You could do your own additional monkeypatch of XHR instrumentation (on top of the one we do already) to automatically capture an additional breadcrumb with header details. This isn't exactly straightforward, would be fragile, and I don't really recommend it, just mentioning it as a possibility.

If you want to further discuss either of these options (or other JS-side stuff), feel free to keep commenting here, but anything beyond these would have to be a product decision at the sentry core backend level and is outside the scope of the JS SDK, so I'm going to close this. If you want to discuss that further, I recommend opening an issue on getsentry/sentry.

[raine]

Why was this closed? Would be great to have e.g. correlation IDs from specific custom header shown alongside xhr breadcrumb in the Sentry UI. Could be solved the same way as #2904

[csvan]

Would like to second this - we attach custom tracing headers to all our calls and it would be extremely useful to be able to see those directly in the breadcrumb to continue tracing.

A workaround right now is to look up the corresponding request in the associated Replay, but this is sometimes a lot of extra work for a relatively simple thing.

Replays allow including custom headers, would love to see the same thing implemented here.