OpenPipe

OpenPipe develops tools for customizing language models and training AI agents. Its original managed platform helped application developers capture production prompts and responses, turn them into training data, and deploy task-specific models through OpenAI-compatible endpoints. That workflow supported applications such as data extraction and classification. Its commercial model-training and inference functionality now resides within Weights & Biases.

Founded in 2023 by Kyle Corbitt and David Corbitt, OpenPipe extended its work from fine-tuning models to reinforcement learning for multi-step agents. Its Agent Reinforcement Trainer (ART) integrates GRPO training into Python applications, separating application workflows from GPU-based training and inference through a client/server architecture. Developers assign rewards to agent trajectories, and the training loop updates LoRA adapters before running further trials. Its RULER tooling supplies automatic reward generation, helping developers construct the feedback used in reinforcement learning.

CoreWeave completed its acquisition of OpenPipe in 2025, and OpenPipe’s team remains there working on model reliability. Following migration of core functionality, including model distillation, its legacy platform retirement ended model training and inference on OpenPipe.ai effective July 30, 2026. Customers were offered automated migration of existing models to W&B Inference; open-source ART remains supported rather than being retired with the hosted service.