Baseten announced on November 6, 2026 that Serverless Loops is generally available, opening its managed SDK for supervised fine-tuning and reinforcement learning on open models to everyone. The service uses per-token training billing and provides a direct path from checkpoints to Baseten Dedicated Inference. Loops is built around a division of labor: users supply the training signal, while Baseten operates the GPUs, kernels, model architectures and distributed-training backend. The Python SDK…