ExplainThisRepo

ExplainThisRepo is a CLI that generates plain-English explanations of any codebase (GitHub repositories and local directories) by analyzing project structure, READMEs, and high-signal files.

It helps developers quickly understand unfamiliar codebases by deriving architectural explanations from real project structure and code signals, producing a clear, structured EXPLAIN.md.

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Key Features

• Generates architectural summaries from repository structure and code signals
• Fetches public repositories by GitHub URLs (with or without https), owner/repo format, issue links, query strings, and SSH clone links
• Analyzes repository data including file tree, configs, entrypoints, and high signal source files
• Extracts repo signals from key files (package.json, pyproject.toml, config files, entrypoints)
• Builds a file tree summary to understand project architecture
• Detects programming languages with the GitHub API
• Analyzes local project directories using the same pipeline as GitHub repositories
• Generates a structured plain-English explanation grounded in actual project files
• Outputs the explanation to an EXPLAIN.md file in your current directory or prints it directly in the terminal
• Multi-mode command-line interface

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Modes

• (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

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Configuration

ExplainThisRepo supports multiple LLM models:

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

Quick setup (recommended)

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: 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

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Flexible Repository and Local Directory Input

Accepts various formats for repository input, full GitHub URLs, issue links, 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.

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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).

Usage

Basic

Writes a full explanation to EXPLAIN.md:

explainthisrepo owner/repo

Example:

explainthisrepo facebook/react

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Quick mode

Prints a one-sentence summary to stdout:

explainthisrepo owner/repo --quick

Example:

explainthisrepo facebook/react --quick

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Detailed mode

Writes a more detailed explanation of repository structure and architecture:

explainthisrepo owner/repo --detailed

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Simple mode

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

explainthisrepo owner/repo --simple

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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, README, entrypoints) 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.

Version

Print the installed CLI version:

explainthisrepo --version

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Diagnostics

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

explainthisrepo --doctor

Set GitHub Token

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

export GITHUB_TOKEN=yourActualTokenHere

Termux (Android) install notes

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

Recommended install (Termux)

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]"

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

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License

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

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Author

Caleb Wodi

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