What is Code Wiki?
Code Wiki is a documentation tool from Google that reads an entire code repository and builds a structured wiki for it. Google launched it in public preview in November 2025 for public GitHub repositories. Instead of relying on a README that may be out of date, you get pages that explain how the project is organised, what each part does and how the pieces connect.
The wiki is regenerated as the code changes, so it stays current. Pages include architecture, class and sequence diagrams, and every explanation links back to the relevant files. A Gemini-powered chat agent sits on top, so you can ask questions such as where a feature is implemented or how a request flows through the system. You can search for a repository on codewiki.google or request a wiki for one that is not indexed yet. Google has said a Gemini CLI extension for private repositories is on a waitlist.
Main Features
- AI-written wiki for public GitHub repositories
- Updates automatically when the code changes
- Architecture, class and sequence diagrams
- Gemini chat that answers questions about the codebase
- Explanations link straight to source files
- Request wikis for repositories not yet indexed
How to Get Started with Code Wiki
- Open codewiki.google in your browser.
- Search for a public GitHub repository by name.
- Browse the generated pages and diagrams.
- Use the chat panel to ask questions about the code.
Code Wiki Pricing
Code Wiki is free for public repositories and has no paid plan. It is in public preview, so features may change.
Who Should Use It?
- Developers onboarding onto unfamiliar codebases
- Open-source contributors
- Students studying real-world projects
- Engineers evaluating libraries before adopting them
- Technical writers looking for a starting point
Code Wiki Alternatives
- Greptile: AI that understands your codebase and reviews pull requests.
- Mintlify: Developer documentation platform with AI writing help.
- Sourcegraph Cody: AI coding assistant with deep code search across repositories.
Frequently Asked Questions
Is Code Wiki free?
Yes. Code Wiki is free for public GitHub repositories, with no paid plan.
Does Code Wiki work with private repositories?
Not on the website. Google has announced a Gemini CLI extension for private repositories, available through a waitlist.
How does Code Wiki stay up to date?
It regenerates the wiki as the repository changes, so the documentation follows the current code.