How do I understand a new codebase with AI?

Give the model the file tree and key files and ask for the architecture and entry points — which is what the onboarding prompts here do.

Can it explain code I didn't write?

Yes — explaining unfamiliar code is one of the strongest LLM use cases. These prompts focus the explanation on what you need to make a change.

Does it need my whole repo?

No — it works from the structure plus the relevant files. These prompts ask for what matters instead of the entire codebase.

AI Prompts to Onboard to a Codebase

Get oriented in an unfamiliar repo fast — architecture, entry points, and where to make a change.

What to know

Dropping into an unfamiliar codebase is slow. These prompts walk a repo and explain its architecture, the main entry points, and where a given change should go — so you're productive in an afternoon instead of a week. They're built to summarise structure without drowning you in detail. Bring your own key and run them on the model you prefer.

2 prompts for codebase onboarding

Onboard me to an unfamiliar codebase

✓ Verified

Point it at a README and file tree and get a map: what the repo really does, the files that matter most, and a sane first task.

CLAUDE-OPUS-4-700by Oort

Onboard me to an unfamiliar codebase

Paste a README and the top-level file tree. Get a plain-English map: what the repo really does, the files that matter most, the request lifecycle, and a safe first task.

CLAUDE-OPUS-4-700by Oort

Codebase Onboarding prompts — FAQ

How do I understand a new codebase with AI?: Give the model the file tree and key files and ask for the architecture and entry points — which is what the onboarding prompts here do.
Can it explain code I didn't write?: Yes — explaining unfamiliar code is one of the strongest LLM use cases. These prompts focus the explanation on what you need to make a change.
Does it need my whole repo?: No — it works from the structure plus the relevant files. These prompts ask for what matters instead of the entire codebase.