Understand Codebases with GitHub URL and AI Chat

What this is, in plain English

Imagine pasting a GitHub link and then just asking, in plain English, “how does login work here?” and getting an answer, plus a live map of how the files connect. That is what this tool does. It is described as “Google Maps for codebases”: you give it a public repository and it builds a dependency graph (a diagram of which files use which), shows the file tree and contents, and answers questions in a chat.

Be honest about the level: this is a build-it project, not an app you log into. The source walks through building it from a stack of developer tools (Next.js, CopilotKit, a graph library, the GitHub API, and a local AI model), and it leaves the exact commands to you. So it is advanced. This page explains what it does, what it is good for, and the realistic shape of standing it up.

What you can use it for

• Understand an unfamiliar open-source library. Ask how a function or module works instead of reading everything.
• Get into a legacy project fast. Paste an internal repo and ask “how does the login flow work?” to onboard quickly.
• Size up a competitor’s open-source code. Have the AI summarize the key features and structure.
• Teach or study architecture. The live dependency graph makes a codebase’s shape visible.
• The reusable idea: combining the GitHub API, a graph view, and an AI chat over code is a pattern you can adapt.

Tools you need

• CopilotKit (freemium): provides the AI chat interface and keeps it in sync with the app.
• GitHub API (free): fetches the repository’s files and structure (via the Octokit client).
• React Flow (free): draws the interactive dependency graph.
• Ollama (free): runs a local AI model so the question-answering is free and private (an OpenAI key works too, but costs money).
• Next.js (free): the web framework the app is built in (with Tailwind for styling).

How it actually works

You build and run the app, then use it. The realistic shape:

1. Get the project set up. Start from the source’s stack (a Next.js app with CopilotKit, React Flow, Octokit, and Tailwind). If a starter repo is provided, clone it and run npm install.
2. Set up a free AI backend. Install Ollama and pull a model (for example ollama pull llama3). Point CopilotKit’s runtime at Ollama, which is OpenAI-compatible, so the AI runs locally and free.
3. Run the app. Start the dev server (npm run dev) and open http://localhost:3000.
4. Paste a GitHub URL. Enter any public repository’s link; the app fetches its files via the GitHub API.
5. Ask questions. In the chat, ask things like “how does auth work?” and get an explanation, with relevant files highlighted.
6. Explore the graph and files. Watch the dependency graph show how files connect, and click through the file tree to read the code the AI points to.

Words you’ll see, explained

• Dependency graph: a diagram showing which files import or rely on which, the “map” of the codebase.
• GitHub API / Octokit: the way programs fetch a repo’s files; Octokit is the JavaScript client for it.
• CopilotKit: a toolkit for adding an in-app AI chat that can see and act on the app’s state.
• Ollama: runs an AI model locally on your machine, free and private.
• Next.js / React Flow: the web framework and the graph-drawing library used to build the tool.
• Local inference: running the AI on your own computer instead of paying a cloud service.

Original source

Based on “Google Maps for Codebases: Paste a GitHub URL, Ask Anything” by Anmol Baranwal on the DEV Community blog, on building a tool that visualizes and lets you query GitHub repositories with AI.

Notes & variations

• Do you even need to build it? For a quick look at one repo, pasting a file into Claude or ChatGPT and asking is far simpler. This full tool pays off if you explore many codebases and want the graph and chat together.
• Free-tier focus: use Ollama for local, free inference to avoid API costs; just make sure your machine meets its requirements.
• Common pitfall: an incomplete dependency graph usually means the repo is private or the file paths were not all fetched. Use public repos and confirm the fetch succeeded.
• Tip for better results: give context in your questions, “in the authentication module, how does login work?” beats “how does X work?”.