Question

A developer at a fintech company is working in a 2,000-line service file and asks GitHub Copilot to complete a function near the bottom of the file. They notice the suggestion ignores a helper class and several type definitions declared at the very top of the file. A teammate insists Copilot 'reads the whole repository' for every suggestion. What is the most accurate explanation of what is happening during prompt building?

Accepted Answer

Copilot builds a prompt from a limited context window using nearby code, open tabs, and relevant snippets, so distant declarations may be excluded when the context budget is exceeded.

Answer

Copilot always sends the entire file and every file in the repository to the model, so the omission must be caused by a proxy filter blocking the helper class.

Answer

Copilot stores the file permanently on GitHub's servers and retrains its model on it, so declarations only appear in suggestions after the next model retraining cycle.

Answer

Copilot only reads the single line where the cursor is located and ignores all other lines, which is why the top-of-file declarations were not used.