Knowledge files in context Within the channel's material on custom GPTs and prompt engineering, knowledge files are the documents a creator attaches to a custom GPT so the model can draw on curated, authoritative material. Because a custom GPT is still inherently ChatGPT — no new raw capability — the value comes from curation: verified authoritative sources plus a persona. [^a1fafc7f-11fd-5efa-b73b-1635965dd443@1058] The files are that curation in practice: the source material the GPT is steered by, rather than a change to the model itself. Why they matter in the build loop Knowledge files sit alongside the playtest-and-revise workflow demonstrated when building a custom GPT live: build something very basic, play through it, take notes on what went wrong, then feed the notes plus the instructions back and let the model revise. [^a1fafc7f-11fd-5efa-b73b-1635965dd443@4807] In other words, files and instructions are both curated inputs you keep refining through iteration — including re-pasting revised instructions back as Markdown in a code block so numbered structure is preserved. [^a1fafc7f-11fd-5efa-b73b-1635965dd443@3884] - Knowledge files are uploaded documents that give a custom GPT its curated knowledge, alongside instructions and a persona. [^a1fafc7f-11fd-5efa-b73b-1635965dd443@1058]- They represent the curation layer: verified sources rather than new raw capability. [^a1fafc7f-11fd-5efa-b73b-1635965dd443@1058]- They are refined through the same build → playtest → notes → revise loop that sharpens instructions. [^a1fafc7f-11fd-5efa-b73b-1635965dd443@4807]