A post on Hacker News discusses a new plugin for Obsidian that integrates with ChatGPT, allowing users to converse with their notes and gain deeper insights by asking questions. This plugin leverages AI models to index notes and retrieve relevant information, enhancing the traditional search functionality of Obsidian by focusing on concepts instead of just words or phrases. The process involves creating an index using tools like Llama Index or LangChain, which can handle Markdown and other file types, and utilizing OpenAI's services or alternatives for local processing. The plugin aims to empower users by allowing them to generate system prompts and retrieve answers quickly, with additional features like summarizing text or creating connections between notes. The author also encourages experimenting with different models and prompts to enhance note-taking and suggests that these advancements in AI tools make it easier to develop powerful plugins for Obsidian.