This market resolves YES if, before 2026-06-01 00:00 UTC, an official OpenAI API documentation or pricing page publicly lists an API-available model whose public name or model ID starts with GPT-5.3 / gpt-5.3. Examples that would count include GPT-5.3, GPT-5.3 pro, gpt-5.3-chat-latest, or gpt-5.3-codex if OpenAI lists it as an API model. Primary resolver surfaces: - OpenAI API Models: https://platform.openai.com/docs/models - OpenAI API Pricing: https://platform.openai.com/docs/pricing OpenAI News or ChatGPT release notes may be used as backup only if they explicitly say a GPT-5.3-named model is available through the OpenAI API before the deadline: - OpenAI News: https://openai.com/news/ - ChatGPT Release Notes: https://help.openai.com/en/articles/6825453-chatgpt-release-notes Resolve NO if the official surfaces list GPT-5.2, GPT-5.4, GPT-6, or a generic "GPT-5-level" model but no GPT-5.3 / gpt-5.3-named API model before the deadline. Rumors, leaks, third-party wrappers, unreleased eval names, and non-API-only mentions do not count.