Thinking Machines Lab Launches Inkling and Inkling-Small Open-Weight Models

Thinking Machines Lab, the AI research startup founded by Mira Murati, former CTO of OpenAI, has launched Inkling, an open-weights AI model built for customizable, domain-specific workflows. Days later, the company followed up with Inkling-Small, a leaner variant designed to bring most of Inkling’s capability to a much smaller footprint.
Tinker: the platform behind the models
Both models ship through Tinker, Thinking Machines Lab’s training and inference platform. Tinker is designed to simplify and automate lightweight fine-tuning — using LoRA adapters — of large open models, giving developers a hosted API for distributed fine-tuning without hiding the underlying knobs.
Inkling-Small: near-Inkling performance at a quarter of the size
Inkling-Small achieves performance near the level of the full Inkling model at just over a quarter of the size:
- 276B total parameters, 12B active — a mixture-of-experts design
- Natively handles text, images, and audio, just like Inkling
- Ships with efficient variable thinking effort, letting the effort level scale with task difficulty
- Available today on Tinker at 64K and 256K context lengths
According to Thinking Machines Lab, Inkling-Small’s efficiency and size make it a cost-effective choice for many tasks, and the company is offering it — alongside Inkling — at a 50% discount for a limited time. Teams looking to get started can follow the Inkling cookbook published alongside the release.
Why it matters
Inkling-Small’s launch, roughly two weeks after Inkling itself, points to a fast iteration cadence: the model reportedly benefited from an improved pre-training data mix and on-policy distillation using Inkling as a teacher, followed by further agentic-coding reinforcement learning — enough to surpass Inkling on some reasoning and agentic-coding benchmarks despite the smaller size. For architects and engineers evaluating open-weight models for fine-tuning, Inkling-Small is a notable option to track alongside other open multimodal releases.
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