Finch is a Swift CLI tool that generates well-formatted changelogs by comparing two Git versions (tags or branches). It parses commit messages using a configurable tag convention (e.g., `[feature]`) and groups commits into sections (Features, Bug Fixes, etc.) based on user-defined YAML configuration. The tool supports custom format strings with placeholders for tags, messages, contributor handles, and commit hyperlinks, as well as cascading configuration merging from multiple file locations. It is built with SwiftCLI for command routing, Yams for YAML parsing, and the Version library for semantic versioning. The architecture is modular with separate targets for core models, app logic, and utilities, and includes comprehensive unit and snapshot tests.