OpenAI: all AI models and prices in reais

1. Price source: OpenAI - API Pricing (official documentation, Standard table), read on Sep 25, 2026. How the page was read: Markdown page of the documentation (platform.openai.com/docs/pricing.md). robots.txt does not block it; openai.com's terms of use could not be read (they return 403 to bots), so the catalog does not download the page by itself. Reais converted at the selling PTAX rate of the Central Bank of Brazil on Oct 9, 2026: R$ 4.9892 per dollar.
2. The conversation math: 10 agent replies, each reading 8,000 input tokens (instructions, what the company knows and the conversation history) and writing 300 output tokens. This is the basis CertuAI uses to estimate the cost per reply. It does not include cache discounts or the extra tokens of models that “think” before answering, so a reasoning model can come out more expensive. In a CertuAI measurement from Aug 5, 2026, with two real businesses on Gemini, the cost came to between R$ 72 and R$ 77 per 10 thousand messages, below this estimate.
3. Source: LMArena, text leaderboard, public dataset on Hugging Face (CC BY 4.0 license), published Oct 8, 2026, queried Oct 9, 2026. What the number measures: Score from the LMArena text leaderboard, in the style-control version and the overall category: people send the same question to two models without knowing which they are and vote for the better answer, and LMArena turns the votes into a score. The higher it is, the more often the model won. The confidence band is the interval LMArena itself publishes for the score. The rank is the one on the full leaderboard, which has models outside this catalog. How the name was matched: Same company and same name, ignoring periods, spaces and hyphens. It also accepts the name with the reasoning level at the end (high, medium, low, minimal) and the name with a date at the end when LMArena only knows that model by a date.
4. Source: Wikidata (CC0 license), queried Oct 9, 2026. What the number measures: Country (P17), founding date (P571), headquarters (P159) and official website (P856) of the company's item on Wikidata. How the name was matched: Item picked by hand and checked against the official site: the item's site must be on the company's domain.

LMArena in the table: the model's best rank on the Oct 8, 2026 text leaderboard (public LMArena dataset, CC BY 4.0 license); the cell is empty when the model is not on the leaderboard or the name did not match with certainty. Context: the context window reported in the company's official documentation.