OpenAI's August changelog cuts Sol prices and puts a date on them

The cut and its reversal are not the same size. Sol's new $4 per million input tokens implies a pre-August rate of $5, and the new $20 output rate implies roughly $30 ^[1][12][13]. Climbing back up those two steps costs 25% on input and 50% on output, because a cut and a restoration are measured against different bases ^[14]. The published floor runs "at least through November 21, 2026" ^[2], so any 2027 model built on $4 and $20 is built on a rate with no stated life. July's cuts to Luna and Terra came with no promotional label and no end date in the same changelog ^[6].

Teams that took up July's hard spend limits inherit a second-order version of this. Once tracked spend hits the monthly cap, affected requests return 429, with alerts available before traffic is interrupted ^[19]. A rate reversion against a fixed ceiling does not arrive as a larger invoice; it arrives as requests failing earlier in the month than they used to.

The residency arithmetic is the more interesting half. Regional processing endpoints carry a 10% uplift on models released on or after March 5, 2026 that are eligible for data residency ^[8], which puts Sol at $4.40 in and $22 out through a regional endpoint ^[15]. That regional input rate is about 12% below what plain global Sol cost before August ^[16]. The compliance premium is now cheaper in absolute terms than the non-compliant path was six weeks ago. And the routing decision moved into the request: a prefixed domain plus an API key from a project with Global geography selects regional processing per call, with eligibility, retention control, endpoint and model support requirements unchanged ^[7]. Provisioning stops being where geography is decided, and per-call validation becomes where it can fail.

Watch the multipliers, because they stack against the same base. Prompts above 272K input tokens bill at 2x input and 1.5x output for the whole request ^[3], so a long-context regional call is $8.80 in and $33 out ^[18]. Fast mode is twice standard price for Sol and now accepts those long-context prompts at up to 2.5x standard speed ^[5][10], putting Fast at $8 and $40, or $8.80 and $44 with the regional uplift ^[20]. The same prompt text has a wide billing range depending on flags nobody sees in a code review.

Caching sits under all of it. Cache writes bill at 1.25x the uncached input rate ^[4], which is $5 per million for Sol, exactly what an uncached input token cost in July ^[17]. That is why the new Prompt Caching dashboard matters more than a dashboard usually does: cache reads per write, filterable by model and service tier, is the ratio that decides whether the write premium clears ^[9].

One coupling deserves flagging for anyone in the Daybreak program. The daybreak-blue-latest alias currently points to gpt-5.6-sol, with alias pricing adjusted to match the underlying model ^[21]. Defensive security work priced through that alias therefore runs on Sol's promotional number and Sol's November 21 date, not on a separate commitment ^[22]. Ultrafast mode, claimed at up to 14x Standard, remains a limited preview to select customers with no published rate ^[11]. Two of the three levers here have dates attached, and the third has a gate.