As reported by AI Base, on December 22, 2025, an open-source AI painting tool, PromptFill, made its official debut. This innovative tool introduces a unique 'fill-in-the-blank' visual interaction approach. It simplifies the conventional long-text prompts, which often demand memorization and meticulous composition, by breaking them down into distinct variables like 'character', 'action', 'art style', and 'scene'. Users can effortlessly assemble a complete and correctly formatted prompt structure through intuitive point-and-click, drag-and-drop, and fill-in-the-blank actions. The system automatically manages error-prone details, such as comma placement and weight annotation. PromptFill boasts an integrated intelligent classification thesaurus that accommodates user-defined keywords and offers a real-time preview of both the prompt text and its structure. Once constructed, users can easily copy the clean prompt text with a single click or export it as a high-definition long image for direct utilization in popular AI painting software like Nano Banana and Stable Diffusion. The tool has undergone several iterations, reaching version v0.5, and supports both desktop and mobile platforms. Since its launch, it has garnered enthusiastic reception from the open-source community.