In June, we covered X's April pricing shakeup — API posts with links jumping from $0.01 to $0.20, a disclosed 1,900% increase aimed at spam and affiliate flooding. That story is still true. But it's no longer the whole story.
On September 16, X sent developers this notice:
"We're correcting a billing issue that affected Pay-Per-Use charging for X Activity API (XAA) events delivered via webhooks... this change reflects corrected charging going forward — it is not a new product fee and does not require refunds."
Translation: X had a billing bug that was under-charging webhook-delivered Activity API events, and just fixed it. If your bill moved this week, this is very likely why.
Not the same story as April
April was X deliberately raising prices. This is different — it's not a new rate at all, it's X finally billing rates that were already published. Per X's pricing docs, webhook events have been billed per-delivery all along:
- $0.010 — follow/unfollow, DM/chat received
- $0.005 — post.create, profile updates, Spaces/news events
- $0.001 — mute/unmute, block/unblock
Events within the same 24-hour UTC window are deduplicated to a single charge — but there's no free tier.
Why you won't see it coming
Webhook events don't show up in X's standard API usage dashboard at all. That view tracks Read, PostCreate, Content Manage and Total — all outbound calls your app makes. XAA webhook events are the opposite: X pushing notifications into your app. They're billed, but invisible in the counter you'd naturally check first.
In our own account, daily API cost roughly doubled over one week with no rise in outbound request volume — flat or lower, in fact. The entire delta traced back to webhook events that had been under-billed and were now billed correctly.
What to actually do about it
- Check console.x.com → Webhooks, not just Usage, to see which XAA event types you're subscribed to.
- Unsubscribe from event types you don't act on — paying per delivery for notifications you ignore is pure waste.
- Model webhook cost separately from post cost. They're two independent line items now.
- Don't assume a flat request-volume chart means a flat bill. It doesn't.
LSE_SMM is auditing its own XAA webhook usage in light of this correction and monitoring whether it has any downstream effect on platform pricing. As with April's change, our priority is absorbing infrastructure-level cost shifts at the platform level rather than passing surprise costs on to the people using it.
The bigger lesson for anyone running automated social tooling: platform APIs now have multiple independent billing surfaces, and they don't all show up in the same dashboard. Auditing "what we're charged for posting" is no longer enough — you have to audit what you're being notified about, too.