---
title: Using GitHub Copilot to explore a codebase
shortTitle: Explore a codebase
intro: '{% data variables.copilot.copilot_chat %} can help you gain an understanding of the content, structure, and functionality of a codebase.'
topics:
- Copilot
versions:
feature: copilot
redirect_from:
- /copilot/using-github-copilot/guides-on-using-github-copilot/using-copilot-to-explore-a-codebase
- /copilot/tutorials/using-copilot-to-explore-a-codebase
contentType: tutorials
category:
- Scale institutional knowledge
- Author and optimize with Copilot
---
## Introduction
If you've been assigned to work on a project that you're not familiar with—or you've found an interesting open source project that you want to contribute to—you'll need some understanding of the codebase before you can start making changes. This guide will show you how to use {% data variables.copilot.copilot_chat %} to explore a codebase and quickly learn about the project.
## Working with {% data variables.copilot.copilot_chat_short %}
Throughout this guide, we'll work with {% data variables.copilot.copilot_chat_short %} on {% data variables.product.prodname_dotcom_the_website %}, which you can find at [github.com/copilot](https://github.com/copilot?ref_product=copilot&ref_type=engagement&ref_style=text).
## Attaching a codebase
Before {% data variables.copilot.copilot_chat_short %} can help you, you need to attach the codebase you want to explore.
1. On {% data variables.product.github %}, navigate to [github.com/copilot](https://github.com/copilot?ref_product=copilot&ref_type=engagement&ref_style=text).
1. In the text box, click **{% octicon "plus" aria-label="Add attachments" %} Add repositories, files, and spaces**, then click **Repositories**.
1. Search for and select the repository you want to explore.
{% data variables.copilot.copilot_chat_short %} now has access to the code in that repository, and you can start asking questions about it.
## Example prompts
The following prompts are examples of the kind of questions you can ask {% data variables.product.prodname_copilot_short %} to help you find out about a codebase.
### General questions
* `Based on the code in this repository, give me an overview of the architecture of the codebase. Provide evidence.`
* `Which languages are used in this repo? Show the percentages for each language.`
* `What are the core algorithms implemented in this repo?`
* `What design patterns are used in this repository? Give a brief explanation of each pattern that you find, and an example of code from this repository that uses the pattern, with a link to the file.`
### Specific questions
Whether these questions are useful will depend on the codebase you're exploring.
* `How do I build this project?`
* `Where is authentication handled in this codebase?`
* `Analyze the code in this repository and tell me about the entry points for this application.`
* `Describe the data flow in this application.`
* `Analyze the code in this repository and tell me what application-level security mechanisms are employed. Provide references.`
## Understanding the files in a directory
Use {% data variables.product.prodname_copilot_short %} to help you understand the purpose of the files in a directory, or individual files.
To find out about the files in a directory:
1. Navigate to the directory on {% data variables.product.prodname_dotcom_the_website %}.
1. In the top right corner of the page, click the {% data variables.product.prodname_copilot_short %} icon (**{% octicon "copilot" aria-label="Copilot icon" %}**) to open {% data variables.copilot.copilot_chat_short %}.
{% data variables.product.prodname_copilot_short %} will use the directory contents as context for your question.
1. Ask {% data variables.product.prodname_copilot_short %}: `Explain the files in this directory`.
To find out about a specific file:
1. Open the file on {% data variables.product.prodname_dotcom_the_website %}.
1. In the top right corner of the page, click the {% data variables.product.prodname_copilot_short %} icon (**{% octicon "copilot" aria-label="Copilot icon" %}**) to open {% data variables.copilot.copilot_chat_short %}.
{% data variables.product.prodname_copilot_short %} will use the file contents as context for your question.
1. For a small file, ask {% data variables.product.prodname_copilot_short %}: `Explain this file`.
1. For a large file, ask: `Explain what this file does. Start with an overview of the purpose of the file. Then, in appropriately headed sections, go through each part of the file and explain what it does in detail.`
## Understanding specific lines of code
Use {% data variables.product.prodname_copilot_short %} to help you understand specific lines of code in a file.
To find out about a specific line of code:
1. On {% data variables.product.github %}, navigate to a repository and open a file.
1. Select the lines by clicking the line number for the first line you want to select, holding down Shift and clicking the line number for the last line you want to select.
1. To ask your own question about the selected lines, click the {% data variables.product.prodname_copilot_short %} icon ({% octicon "copilot" aria-hidden="true" aria-label="copilot" %}) to the right of your selection.
This displays the {% data variables.copilot.copilot_chat %} panel with the selected lines indicated as the context of your question.
1. To ask a predefined question, click the downward-pointing button beside the {% data variables.product.prodname_copilot_short %} icon, then choose one of the options.
1. If you clicked the {% data variables.product.prodname_copilot_short %} icon, type a question in the prompt box at the bottom of the chat panel and press Enter.
## Understanding a specific file or symbol
Use {% data variables.product.prodname_copilot_short %} to help you understand the purpose of a specific file or symbol in the codebase. A symbol is a named entity in the code, such as a function, class, or variable.
1. On {% data variables.product.github %}, navigate to a repository and open a file.
1. At the top of the file, click the {% data variables.product.prodname_copilot_short %} icon (**{% octicon "copilot" aria-label="Copilot icon" %}**) to open {% data variables.copilot.copilot_chat_short %}.
{% data variables.product.prodname_copilot_short %} will display the file contents in a split screen as context for your question.
1. If you want to ask about a specific symbol, highlight the symbol in the file.
1. In the prompt box, type a question about the file or highlighted symbol, and press Enter.
{% data variables.product.prodname_copilot_short %} replies in the chat panel.
> [!TIP]
>
> {% data reusables.copilot.semantic-index-info %}
## Finding out about commits
One good way to familiarize yourself with a project is to look at the recent work that's been happening. You can do this by browsing the recent commits.
{% data reusables.repositories.navigate-to-repo %}
{% data reusables.repositories.navigate-to-commit-page %}
1. Click a commit message to display a diff view for that commit.
1. In the {% data variables.copilot.copilot_chat_short %} panel, enter: `What does this commit do?`.
1. If necessary, you can follow up by entering: `Explain in more detail`.
## Using the Insights tab
In addition to using {% data variables.product.prodname_copilot_short %} to help you become familiar with a project, you can also use the **Insights** tab on {% data variables.product.prodname_dotcom_the_website %}. This gives you a high-level overview of the repository.
For more information, see [AUTOTITLE](/repositories/viewing-activity-and-data-for-your-repository/using-pulse-to-view-a-summary-of-repository-activity) and [AUTOTITLE](/repositories/viewing-activity-and-data-for-your-repository/viewing-a-projects-contributors).
## Further reading
* [AUTOTITLE](/copilot/using-github-copilot/copilot-chat/asking-github-copilot-questions-in-github)