Thinking Machines Lab Launches Inkling 2 Small with Open Weights Pending

Thinking Machines Lab introduced Inkling 2 Small on November 5, 2026, making its second-generation model available through Tinker with closed weights. The sparse Mixture-of-Experts system has 594 billion total parameters and 17 billion active parameters, targeting long-horizon autonomous work alongside coding, vision and knowledge tasks. At launch, Tinker Playground provides inference-only access, while Tinker supports fine-tuning and sampling under the platform’s terms.

Thinking Machines intends to publish full weights under Apache 2.0 in the week following the announcement, conditional on completed external safety testing and red-teaming. Fine-tuned checkpoints would become downloadable with those weights, and additional platforms are planned after safety testing. The model card describes a 48-layer decoder-only transformer that routes each token to eight of 384 experts, combining local and global attention.

It accepts text and images, projects them into a shared hidden space for joint processing, and generates text. The context window reaches 1 million tokens, with support for MXFP8 and NVFP4 numerics and variable effort settings. Initial pretraining covered 8.4 trillion tokens of natural-language, code and image data over 68 hours on NVIDIA GB300 NVL72 racks,…