#Introduction

MDReader is a local Markdown library for the notes, research, architecture, decisions, and structured knowledge you already have. It gives those files a reading surface, a document outline, source-aware search, related notes, and side-by-side editing.

There is no import step and no new format. You point MDReader at a folder of .md files and it reads them where they live.

#What MDReader is

• A reader and editor. It pairs a 70-character reading measure, a real type system, and a live outline with side-by-side Markdown editing.
• Local-first. Your source Markdown stays in the folder you chose. CatDB keeps its private, rebuildable index under MDReader's app data directory rather than placing database files beside your notes.
• Semantic where it helps. Search fuses literal term matching with meaning, and every hit carries its provenance back to the exact source lines.

#What MDReader is not

Indexing and search leave source files unchanged. The editor writes Markdown only after you explicitly save. MDReader uses the structure in the text and links every result back to its source.

#Next

Read the Quick tour to see the reading surface, the outline, and the Cmd+K palette in about two minutes.