OpenAssistant was an open-source project created to make a capable chat-based language assistant and the data needed to train it available to the public. The project combined a conversational application with a large community data-collection effort in which volunteers submitted, ranked, and labeled prompts and responses to improve open assistant models.

The repository contains infrastructure for the web frontend, backend services, data collection, and local development, while the resulting datasets were published separately for broader research and model training. The project was motivated by the idea that open conversational AI could play a role similar to open generative-image projects by enabling experimentation and innovation outside proprietary systems.

OpenAssistant has now been completed and is no longer an active development project. Its most important lasting outputs are the open datasets, including the final OASST2 release, and the experience it provided in large-scale community collection of conversational preference data. It remains relevant to researchers studying open instruction tuning, preference datasets, and the history of community-built chat assistants.