Onboard to an unfamiliar codebase in an afternoon
Cursor maps an unfamiliar codebase and builds a mental model: entry points, data flow, test strategy, and where to start reading.
A guided tour: where requests enter, how data moves, what tests cover, and the three files you should read first.
- 1
Start Cursor in the repo root
Point Cursor at the full repository. A partial checkout will miss the structure.
- 2
Read the three files it names
Open them in order. Confirm that reading those three gives you a sense of the codebase's style and assumptions.
- 3
Trace one request end-to-end
Follow the data flow guide and step through the code. If the guide is wrong, correct it before you trust it.
The prompt to paste
I am new to this codebase and need a map before I start changing it. Analyze the repository structure and help me build a mental model. What I need: 1. Entry points: where do HTTP requests, CLI commands, or function calls enter the system? 2. Data flow: for a typical request, what is the path from entry to database and back? 3. Core abstractions: what are the main domain objects or data structures I will see everywhere? 4. Test strategy: what test runner is used, where are the tests, and what is tested vs untested? 5. Configuration: where are environment variables, feature flags, and deployment settings defined? 6. Three files: which three files should I read first to understand how this codebase thinks? Rules: - Use the actual file paths and module names from the repo. - Do not describe every file. Highlight the load-bearing pieces. - If the codebase has no tests, say so and identify the riskiest module to change. - If the codebase has multiple entry points (web + CLI + background jobs), map each one separately. Return a 1-2 page guide I can reference while I work.
A generated map can be outdated or wrong. Verify the entry points by running the application and checking the logs.
Sample case written by Hidden Logic Lab. Not affiliated with Cursor.
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