Thinking Machines Lab released Inkling, its first open-weights model, on July 15, 2026. Inkling is a Mixture-of-Experts transformer with 975B total and 41B active parameters, a context window up to 1M tokens, pretrained on 45 trillion tokens of text, images, audio and video, with an encoder-free multimodal design (dMel spectrograms for audio, 40x40 pixel patches with a four-layer hMLP for vision). It offers a controllable thinking-effort setting from 0.2 to 0.99, and the company reports matching Nemotron 3 Ultra on Terminal Bench 2.1 at roughly a third of the tokens, plus scores of 91.4% on VoiceBench and 73.5% on MMMU Pro. Weights are on Hugging Face and the model is available to fine-tune on Tinker, with a new Inkling Playground in the Tinker console. A preview of Inkling-Small, with 12B active parameters, was also shared. The company states Inkling is not the strongest model available, open or closed.