Inkling Small is an open-weight multimodal Mixture-of-Experts model from Thinking Machines Lab, featuring 276B total parameters with 12B active parameters per token. It natively accepts text, image, and audio inputs and generates text, supporting a context window of up to 524K tokens. Designed as a more efficient sibling to the flagship Inkling model, it delivers near-equivalent performance at roughly one-quarter the size. The model supports advanced reasoning with a configurable effort dial, and is intended for use in agentic systems, coding assistants, multimodal applications, and fine-tuning via Thinking Machines' Tinker platform.