piotr-jura-udemy/openai-ts-course ? reverse-engineered prompt

Build me a small TypeScript project that shows a few practical ways to use the OpenAI API.

I want it to include simple example scripts for chatting with the model, getting structured responses back, using tools, and a basic chat experience that can answer questions from some local knowledge files. There should also be a finance themed chat example that uses the same idea in a more realistic way.

Keep it easy to run from the command line, with clear setup instructions, and make the examples readable so I can learn from them. If you need to check current OpenAI docs online for the latest API details, do that.

Please make the code clean, use modern TypeScript, and organize it so each example is separate but still feels like part of one small learning project.