Links to merged research output records now redirect automatically

Occasionally, Altmetric identifies two different records as duplicates of the same research output and merges them, retiring one record in favour of the other. Previously, anything still pointing at the retired record (e.g. a badge, a stored link, an API call) would simply fail, as if the record no longer existed.

We have now improved this, so that merged records no longer break links or badges. What changes for you depends on how you use Altmetric data.

If you have a link to an Altmetric Details Page

Previously, when a record got merged, its Details Page URL (in the format altmetric.com/details/<id>) would show a "not found" page, with the risk of users finding that links they had bookmarked, pasted into a document, or saved anywhere were suddenly broken.

Now, any link to altmetric.com/details/<id> automatically redirects to the current page for the research output, even in the case of a record that was later merged into another.

If you have an Altmetric badge embed

The majority of users of Altmetric Badges will likely notice no changes. Most badges are keyed by DOI, PMID, or another identifier; those already resolve correctly after a merge and were never affected by this issue.

Edge case: badges embedded using the raw data-altmetric-id attribute would previously stop rendering if that specific record was later merged into another. That's now fixed too: badges for merged records will render automatically, with no changes needed on users' end.

If you're calling the Altmetric Details Page API directly

When a research output you've requested has been merged into another, the retired ID no longer returns a 404. Instead:

• GET /v1/id/:id, GET /v1/fetch/id/:id, and GET /v1/details/:id return HTTP 200 with the surviving citation's data, plus a new top-level field:

  "merged_into": { "altmetric_id": <new_id> }

  Check for this field if you want to detect a merge and update any records you've stored yourself.

• GET /v1/post_counts/id/:id resolves transparently to the surviving citation's counts — no merged_into field, no code changes required.

• Records that never existed at all still return a 404. This change only affects records that were genuinely merged and retired.