Three weeks after United States export controls pulled Claude Fable 5 offline for every developer outside the country, Anthropic’s flagship coding model was back online, and two rivals had already moved. OpenAI pushed GPT-5.6 Sol to general availability on 9 July 2026. Google had quietly put Gemini 3.1 Pro into preview back in February. For engineering teams in Dublin, Cork and Galway picking a frontier model for a new project this quarter, the decision now comes down to three systems with three very different price tags, context windows and risk profiles. This comparison lines up Claude Fable 5, GPT-5.6 Sol and Gemini 3.1 Pro on the numbers that actually change a procurement decision: API pricing per million tokens, context window size, independent benchmark scores, and what happened when a US government export order took the highest-rated of the three offline for nineteen days. It also covers where each model is already running in production, how open-weight alternatives like Kimi K3 and Mistral Small 4 change the cost math for self-hosting, and what an Irish or EU team building on any of these three vendors needs to know about data residency before signing a contract. Claude Fable 5 is the first release in what Anthropic calls its Mythos class, a new model tier the company launched on 9 June 2026 alongside a sibling model, Mythos 5. Anthropic built the Mythos line specifically for long-hor