Following up on this thread with an update on the VIAF reconciliation service.
I reached out to @codeforkjeff, who maintains the public VIAF reconciliation service. He confirmed the service remains largely unusable because OCLC's VIAF API severely rate-limits it, returning a high number of HTTP 429 errors (too many requests). Despite reducing the number of requests, the issue persists. Jeff also contacted OCLC twice but hasn't received a response.
Running conciliator locally doesn't eliminate VIAF's API rate limits, although the restrictions may vary depending on the IP address, so some users may have more success than others.
We also looked at VIAF usage in the 2026 OpenRefine User Survey. VIAF remains among the most frequently reported reconciliation services, but none of the respondents we contacted by email reported using it recently. Some users mentioned retrieving VIAF identifiers through Wikidata instead.
We presented these findings during our October 15 Community Call on Reconciliation Services. The recording is available on YouTube, with the VIAF status discussion starting at 1:16:40.
Thanks again to @codeforkjeff for maintaining this service over the years and for sharing information about the issues.
If anyone is successfully reconciling directly against VIAF, using another service or a locally hosted instance, please share your experience. It would be helpful to understand what options remain.