Follower count is the number of accounts subscribed to an account's updates. It is the most requested field in any social data API and the one most often returned incorrectly.
Not because it is hard to find. Because it has neighbours.
The neighbours
Almost every platform's data contains several counters in the same object, with names one character apart:
| Field | Counts |
|---|---|
followers_count |
People following this account |
followings_count |
Accounts this one follows |
collectionFollowingCount |
Followers of a collection, not the account |
subscriberCount |
Same idea, different platform vocabulary |
On one network, a profile object holds seven counters and one of them is the right one. The dangerous neighbour is followings_count — a single letter from followers_count — and on some very large accounts it is zero. Read it and the bug presents as "this account has no followers", not as an error. That is a silent failure, and it is why we read by exact field name and never by matching a Count suffix.
Why the anchor is mandatory
Some platforms do not return 404 for a handle that does not exist. One returns HTTP 200 with an account-not-found page, around 80 KB of it. Without an anchor — a field that must be present for the document to be a profile — a parser will extract numbers from that page and hand you a profile for an account that was never there.
When null is the correct answer
Not every platform exposes it. One large network's public profile does not publish following count or post count at all, so both come back null on our route rather than zero. A zero would assert the account follows nobody.
The general rule, and it applies to every field in a unified schema: null means we could not get it, 0 means we measured zero, and collapsing the two is how a dashboard reports a collapse that never happened.
Counting it over time
A single follower count is a fact about one instant. What most questions actually need is the change — which requires somebody to have stored the number hourly, before you asked. That is what the archive does, and why a live-only API cannot answer it however fast it responds.