Whatsun

Whatsun is a command-line tool and Go library for code analysis.

The primary use case is to generate a repository digest (a concise, token-efficient summary), which can be used in an LLM prompt to provide context for code-related tasks.

Features

CLI Commands

• whatsun digest - Generate a repository summary for LLM context, including detected technologies and the contents of key files
• whatsun analyze - Perform detailed (rule-based) analysis and show detected frameworks, build tools, and package managers
• whatsun deps - List all dependencies found across the repository with their sources and versions
• whatsun tree - Display a concise repository file structure

Core Capabilities

• Multi-language dependency detection (Go, JavaScript, Python, Java, PHP, Ruby, Rust, and more)
• Configurable rules (using CEL expressions), which by default identify frameworks, build tools, and package managers
• Handling of Git excludes (.gitignore and .git/info/exclude files) when analyzing the repository.
• Fast processing including caching and parallel analysis.
• A digest structure optimized for use in an LLM context, containing:
  • A token-efficient file tree.
  • The reports from rule-based analysis.
  • The contents of automatically selected files (filtered using .aiignore and .aiexclude files, sanitized using secret detection, and truncated).

Installation

CLI Tool

go install github.com/upsun/whatsun/cmd/whatsun@latest

Go Library

go get github.com/upsun/whatsun

Usage

Command Line

# Generate repository digest (using a local file path or a URL)
whatsun digest [repository]

# Analyze project structure
whatsun analyze [repository]

# List all dependencies
whatsun deps [repository]

# Show file tree
whatsun tree [repository]

Run whatsun --help for detailed command options.

Configuration

Analysis rules are defined in YAML files in the config directory using CEL expressions for pattern matching. See docs/rules.md for rule configuration details.