Released by Google on November 13, 2025, Code Wiki is a developer platform built to accelerate code understanding. Connect a repository from GitHub or another provider and Gemini reads the entire codebase to generate a structured wiki. Architecture diagrams, sequence diagrams, and dependency explanations are produced together, and the documentation follows along as the code changes. A chat interface grounded in the generated wiki lets you ask questions such as “where is this function called from?” At launch it is offered as a public preview, free for public repositories.
Key Features
- Automatic wiki generation from the whole repository: Point it at a repository and Gemini scans the code, producing readable documentation organized into an overview, module structure, and the main processing flows. Even a repository with nothing but a README becomes navigable.
- Documentation that follows code changes: Documentation is regenerated after each commit, so it is far less likely to become the “internal wiki nobody updated.” It tackles head-on the problem most likely to occur in real development ─ documentation going stale.
- Automatic architecture, class, and sequence diagrams: Not just prose but diagrams are generated automatically, and they stay in sync with the current state of the code. That removes much of the work of redrawing design materials by hand.
- Chat about your codebase: A Gemini-based chat answers using the already-generated wiki as context. Unlike pasting code into a general-purpose AI chat, the answers reflect the repository as a whole.
- Jump straight from an explanation to the code: Passages in the documentation link to files and functions, making it easy to read a conceptual explanation and then check the implementation.
- Gemini CLI extension for private repositories (in preparation): An extension is announced that runs on your own infrastructure so your code never leaves your environment. Check the official site for current availability.
Pricing
| Plan | Price | What’s included |
|---|---|---|
| Public preview (public repositories) | Free | Wiki generation, automatic diagrams, chat |
| Private repositories (Gemini CLI extension) | Contact for details | Runs in your own environment. See the official announcement for availability and terms |
Pricing reflects information as of August 2026. Check the official site for the latest pricing.
Pros & Cons
✅ Pros
- Grasp the overall picture of a repository quickly, even when documentation is missing or out of date
- Regeneration follows commits, so nobody has to maintain freshness by hand
- Diagrams are generated automatically, reducing the effort of preparing design materials
- Free to try for public repositories, making it easy to adopt as a research tool when reading open source
- Chat grounded in the wiki means reading and asking happen in the same place
⚠️ Cons
- It is a public preview, so specifications and terms of availability may change
- At launch it cannot handle private repositories directly; applying it to internal code means waiting for the CLI extension
- The generated explanations and diagrams are AI inferences and do not faithfully reproduce design intent or historical context. Review is required
- Leaning too heavily on generated documentation can thin out the record of “why we chose this design,” which humans still need to write
Comparison with Similar Services
| Criteria | Code Wiki | DeepWiki | Mintlify | Swimm |
|---|---|---|---|---|
| Provider | Cognition | Mintlify | Swimm | |
| Main use | Repository analysis and wiki generation | Repository analysis and wiki generation | Building and publishing product docs | Internal docs tied to code |
| Automatic diagrams | Yes (architecture / class / sequence) | Yes | Limited | Limited |
| Ask questions about the codebase | Yes (Gemini chat) | Yes | AI documentation search | Yes |
| Intended reader | Developers reading code | Developers reading code | Readers and users of the docs | Internal development teams |
| Free for public repositories | Free (preview) | Free tier | Free tier | Free tier |
Who Is It For
- Developers who need to understand an unfamiliar open source project or an inherited repository quickly
- Teams whose internal wiki sits untouched because nobody has time to write documentation
- Lead engineers preparing onboarding material for new members
- Anyone who wants to spend less time redrawing design diagrams every time the code changes
- Learners who want something they can ask questions of while reading code
Summary
Code Wiki answers a chronic problem in software development ─ documentation starts going out of date the moment it is written ─ by continuously generating it from the code itself. Public repositories are free to try, so a good starting point is to register an open source project you want to read and judge the quality of the generated wiki and diagrams for yourself. Keep in mind that the output is an AI interpretation and cannot cover the reasoning behind design decisions or operational caveats. It works best when you decide up front what humans should record and what generation can handle.