What is Corroboration?
Verified 5 August 2026
Twelve copies of one wire story and six independent reports look identical in a ranked list — and the twelve copies look more convincing. That is exactly backwards, and it is a reliable way for an agent to become confidently wrong.
Counting distinct asserting hosts separates them. The engineering subtlety is that deduplication must not destroy the count: when a near-duplicate is rejected at admission, its host has to be recorded against the surviving passage, or compaction erases the evidence.
unlob exposes this as independent_sources on every hit, as a min_independent_sources filter, and through the corroborate endpoint.
How unlob handles this: corroborate
Common questions
What is Corroboration?
Corroboration counts how many independent sources assert the same claim, distinguishing widely reported facts from one story copied many times.
How does Corroboration work in practice?
Counting distinct asserting hosts separates them. The engineering subtlety is that deduplication must not destroy the count: when a near-duplicate is rejected at admission, its host has to be recorded against the surviving passage, or compaction erases the evidence.
See it working
The free tier is 10,000 requests a month with no card — enough to test any of this against your own queries.