OpenAI has released the GPT-5.6 series, which includes three models: Sol, positioned against Claude Mythos Terra, positioned against Claude Fable Luna, a cheap small model with performance similar to GPT-5.5 The names pay tribute to Web3 projects Solana and the zeroed-out Luna. Considering Altman has launched a crypto project before at ethereum:0x163f8c2467924be0ae7b5347228cabf260318753, it’s not surprising.