Tab completion & the chat sidebar
Goal. Learn the two everyday tools: Tab autocomplete as you type, and the chat sidebar that understands your own files.
Start typing `def average_expression(` in analysis.py and let Tab suggest the rest. Then ask the chat: "What does the function I just wrote do, and how would I call it on a column named TP53?"
Tab completion fires as you type — press Tab to accept a suggestion. The chat sidebar already knows your open files, so you can ask about your code, not generic examples.
- 1Start typing a function and watch Tab completion suggest whole lines and functions ahead of you; press Tab to accept, or keep typing to ignore it.
- 2Open the chat sidebar and ask a question about your own project in plain English — Cursor reads your files to answer, so the reply is grounded in your actual code.
- 3Use chat for understanding and small targeted edits; use Tab for the moment-to-moment typing. Both work on the free plan within its limits.
You'll see. Autocomplete finishing your lines as you type, and the chat answering questions about the exact code in your project.
Cost. Both Tab completion and chat draw on your plan's included usage. On Hobby these are limited; Pro ($20/mo) adds generous included usage so you rarely think about it.
Takeaway. Tab is for speed while typing; the file-aware chat is for asking questions and making small, located changes.