ExplainThisRepo

The fastest way to understand any codebase.

ExplainThisRepo analyzes real project signals; configs, entrypoints, manifests, dependencies, file structure and high-signal files producing a clear, structured EXPLAIN.md that explains what the codebase does and how it is organized in plain English.

Key Features

• Understand any GitHub repository in seconds
• Derives architectural summaries from repository structure and code signals. Not blind AI summarization.
• Extract architecture signals from configs, entrypoints, and manifests
• Works with GitHub repositories, local directories, private repositories, and monorepos
• Outputs the explanation to an EXPLAIN.md file in your current directory or prints it directly in the terminal
• Multiple explanation modes (quick, simple, detailed)

Configuration

ExplainThisRepo supports multiple LLM models:

• Gemini
• OpenAI
• Ollama (local or cloud-routed)

Use the built-in init command to configure your preferred model:

explainthisrepo init
# or npx explainthisrepo init

For details about how initialization works, see INIT.md.

Installation

Option 1: install with pip (recommended):

Requirements: Python 3.9+

pip install explainthisrepo
explainthisrepo owner/repo

Alternatively,

pipx install explainthisrepo
explainthisrepo owner/repo

To install support for specific models:

pip install explainthisrepo[gemini]
pip install explainthisrepo[openai]

Option 2: Install with npm

Install globally and use forever:

npm install -g explainthisrepo
explainthisrepo owner/repo

Or without install:

npx explainthisrepo owner/repo

Replace owner/repo with the GitHub repository identifier (e.g., facebook/react).

Option 3: Download standalone binary

Prebuilt standalone binaries are available for macOS, Linux, and Windows.

Standalone binaries require no Python or Node installation and run as a single executable.

Download the latest release:

github.com/calchiwo/ExplainThisRepo/releases/latest

Or install directly:

macOS

curl -L https://github.com/calchiwo/ExplainThisRepo/releases/latest/download/explainthisrepo-darwin-arm64 -o explainthisrepo
chmod +x explainthisrepo

Linux

curl -L https://github.com/calchiwo/ExplainThisRepo/releases/latest/download/explainthisrepo-linux-x64 -o explainthisrepo
chmod +x explainthisrepo

Windows (PowerShell)

curl -L https://github.com/calchiwo/ExplainThisRepo/releases/latest/download/explainthisrepo-win-x64.exe -o explainthisrepo.exe

Flag options

• (no flag) → Full repository explanation written to EXPLAIN.md

• --quick → One-sentence summary

• --simple → Short, simplified explanation

• --detailed → Deeper explanation including structure and architecture

• --stack → Tech stack breakdown from repo signals

• --version → Check installed CLI version

• --help → Show usage guide

• --doctor → Check system health and active model diagnostics

• --llm → Override provider selection

• --token/-t → Set GitHub token for private repositories

Flexible Repository and Local Directory Input

Accepts various formats for repository input, full GitHub URLs (with or without https), owner/repo format, issue links, query strings, and SSH clone links

explainthisrepo https://github.com/owner/repo
explainthisrepo github.com/owner/repo
explainthisrepo https://github.com/owner/repo/issues/123
explainthisrepo https://github.com/owner/repo?tab=readme
explainthisrepo git@github.com:owner/repo.git
explainthisrepo .
explainthisrepo ./path/to/directory

All inputs are normalized internally to owner/repo.

Model selection

The --llm flag selects which configured model backend to use for the current command.

explainthisrepo owner/repo --llm gemini
explainthisrepo owner/repo --llm openai
explainthisrepo owner/repo --llm ollama

--llm works with all modes (--quick, --simple, --detailed).

Command line usage

Default

Writes a full explanation to EXPLAIN.md:

explainthisrepo owner/repo
#e.g. explainthisrepo vercel/next.js

Quick mode

Prints a one-sentence summary to stdout:

explainthisrepo owner/repo --quick
# explainthisrepo facebook/react --quick

$ explainthisrepo vercel/next.js --quick

Next.js is a React framework that provides server-side rendering,
file-based routing, API routes, and build tooling for fullstack
web applications.

---

Detailed mode

Writes a more detailed explanation of repository structure and architecture:

explainthisrepo owner/repo --detailed

---

Simple mode

Prints a short, simplified explanation to stdout. No files are written.

explainthisrepo owner/repo --simple

---

Stack detector

Tech stack breakdown detected from repo signals. No LLM calls are made.

explainthisrepo owner/repo --stack

Local Directory Analysis

ExplainThisRepo can analyze local directories directly in the terminal, using the same modes and output formats as GitHub repositories

explainthisrepo .
explainthisrepo ./path/to/directory

This works with all existing modes:

explainthisrepo . --quick
explainthisrepo . --simple
explainthisrepo . --detailed
explainthisrepo . --stack

When analyzing a local directory:

• Repository structure is derived from the filesystem
• High signal files (configs, entrypoints, manifests) are extracted locally
• No GitHub APIs calls are made
• All prompts and outputs remain identical

This allows analysis of projects directly from the local filesystem, without requiring a GitHub repository.

For private repositories, use the --token/-t option.

Setting a GITHUB_TOKEN environment variable is recommended to avoid rate limits when analyzing public repositories.

export GITHUB_TOKEN=yourActualTokenHere

Version

Check the installed CLI version:

explainthisrepo --version

Diagnostics

Use the --doctor flag to verify the environment, network connectivity, and API key configuration:

explainthisrepo --doctor

Termux (Android) install notes

Termux has some environment limitations that can make pip install explainthisrepo fail to create the explainthisrepo command in $PREFIX/bin.

However, it's recommended you install using:

pip install --user -U explainthisrepo

Make sure your user bin directory is on your PATH:

export PATH="$HOME/.local/bin:$PATH"

Tip: Add the PATH export to your ~/.bashrc or ~/.zshrc so it persists.

Alternative (No PATH changes)

If you do not want to modify PATH, you can run ExplainThisRepo as a module:

python -m explain_this_repo owner/repo

Gemini support on Termux

Installing Gemini support may require building Rust-based dependencies on Android, which can take time on first install:

pip install --user -U "explainthisrepo[gemini]"

For mobile environments like Termux where compiling Python dependencies can be slow, you can also run ExplainThisRepo using the Node.js version:

npx explainthisrepo owner/repo

Special Thanks

• @Spectra010s for implementing the Node.js version of ExplainThisRepo and improving installation support for mobile environments like Termux
• @HalxDocs for implementing the --detailed mode for deeper architectural explanations

Contributions

Contributions are welcome!

If you find a bug, have an idea, or want to improve the tool:

• See CONTRIBUTING for setup and guidelines
• Open an issue for bugs/feature requests
• Or submit a pull request for fixes/improvements

License

This project is licensed under the MIT License. See the LICENSE file for details.

Author

Caleb Wodi

• Email: caleb@explainthisrepo.com
• LinkedIn: @calchiwo
• Twitter: @calchiwo