Tersa is a browser-based visual workflow builder that enables users to construct AI pipelines by connecting nodes representing different operations and model providers. The interface uses ReactFlow for the drag-and-drop canvas and integrates with the Vercel AI SDK Gateway to access text, image, and video models from over 25 providers including OpenAI and Anthropic. Workflows support streaming responses, cost estimation, and reasoning extraction for supported models, with state persisted locally.