# FAQ

**Do I need an API key?**
No. Courses, the four modes and every game work without one. A key (Claude,
OpenAI or Gemini) is only for AI tutoring, generating a course and adding
content with AI. Save it on your profile; it is stored encrypted and never
shown again. Don't want AI at all? Turn on *Do Not Show Me AI Features*
under Privacy and consent on your profile.

**I passed a lesson in Sprint. Why does Study mode still say "in progress" or "needs practice"?**
Passing and mastery are different. A pass is a milestone that stays. Mastery
is a score that rises with practice and fades with time. See
[Getting started](getting-started#when-a-lesson-is-passed).

**Why is a game missing from my course?**
A feature only appears when the course has the data for it. Date Dash needs a
`calendar`, the drill a `paradigm`, Listening a language course with `listening` sentences. See
[Which field switches on what](course-structure#which-field-switches-on-what).

**Can other people see my course?**
Only the people you share it with: **Share** on the course page invites them
by e-mail. They learn from it read-only, with their own progress. See
[Share a course](making-courses#share-a-course).

**My course does not load. What now?**
The error names the file and the field. See
[Fixing validation errors](making-courses#fixing-validation-errors).

**Can ChatGPT, Claude or another LLM write my course?**
Yes. Give it [`/llms.txt`](/llms.txt) or paste the
[course format](course-format.md), then add its replies on the course page.
See [Write lessons with an LLM](making-courses#write-lessons-with-an-llm-you-already-use).

**Why doesn't my theme change my own course's lessons?**
Themed material is shown in built-in courses only for now; your course gets
the theme's colours. See [Themes](using-themes).

**Can I run my own copy?**
Yes, on a Raspberry Pi Zero 2 W or any 64-bit Linux machine:
[Host it yourself](/self-host) is the step-by-step guide,
[Self-hosting](self-hosting) the technical version.

**Can an AI agent outside the app record my progress?**
Yes, through `/api/progress`. Give the agent [Progress across modes](progress).

**I'm a developer. Where are the code docs?**
[Developer documentation](dev).