Build an Modal.com FastAPI for audio mastering. It should su...

Prompt

Build an Modal.com FastAPI for audio mastering. It should support MP3, WAV, M4A (Lossy AAC and ALAC), FLAC, and OPUS. It should ask the user for the genre (out of a list), and the desired LUFS. It should also extract highly detailed audio engineering-related information from the input file. The user can optionally describe the master and feel they want in plain language. Then, using the Vercel AI Gateway, it should allow an LLM (reflection/beam-free) to determine the best way to master the audio. Then the script will apply that. If it is still imperfect, the user can prompt what they want to improve, and then it will be reapplied. It should export in the user's desired format, no matter what the input format was (again, support exporting to WAV, M4A (Lossy AAC and ALAC), FLAC, and OPUS.