MiniMax M3.1 Uses 'Caveman Mode' in Chain of Thought Reasoning to Save Tokens

Users discovered that MiniMax M3.1 (available on OpenRouter under the alias "Space Bunny Alpha") writes its internal Chain of Thought reasoning using ultra-concise "caveman mode" phrasing. This technique significantly reduces token usage during internal reasoning steps without altering the quality of the final response. Reasoning models frequently incur high API costs and latency due to lengthy internal thinking steps before answering. Implementing concise caveman-style reasoning natively shows how AI providers can cut token overhead and inference costs without compromising downstream output accuracy. Testing confirmed that the ultra-short syntax is an inherent behavior of the model's reasoning trace rather than an effect from external prompt extensions like `pi-caveman`. Caveman compression typically strips non-essential grammatical filler while retaining key entities and logic, cutting reasoning token usage by up to 50%.