I recently spent some time looking up metadata for DOIs in the Crossref API at work. Here a few takeaways in case you ever need to do it too: it looks like the most you can look up at a time is 49 using the https://api.crossref.org/works/?filter=doi1,doi2,… endpoint. when looking up 40 at a time the responses take on average 8.08 seconds to return (std dev 5.97) if any of your DOIs fail to match this regex the entire request will fail with a HTTP 400 error r”^doi:10.)/.+$“ the server ca...
