Yes, and it's only for a month. This is an ad.

Which raises the question - who is subsidizing this, and why?

Possibly OAI? If you have OAI tokens you are a captive audience. If you have OpenRouter you are bidding on a free market.

OpenRouter attributes this promotion to OpenAI https://x.com/OpenRouter/status/2089416739398254662

Is this captive audience not going to switch providers for a 50% discount? Especially when the effort is simply swapping one URL for another?

Why though, to AB test/see the impact of a price cut on a platform with multiple competitors?

Wouldn’t that be against TOS?

It might be through a level of indirection via an intermediate provider, offloading the TOS issue to the intermediate provider who couldn't care less.

Right? Should we switch from direct OpenAI API integration to OpenRouter?

What's the incentive here?

Open Responses API doesn't appear to support state management (yet)

OpenRouter and the Vercel AI Gateway.

So yes, presumably a very small share of their total traffic.