80. Obsidian

The lesson

Obsidian (obsidian.md) is a free and flexible note-taking and knowledge-management application whose tagline is "Sharpen your thinking." It is built around one promise: your thoughts are yours. Notes are stored privately on your own device as plain-text Markdown files, so you can open them quickly, work fully offline, and read them with any text editor. No one else can read them — not even the Obsidian company — and because the format is open, you are never locked in and you own your data for the long term. The app is free without limits for personal use and runs on Windows, macOS, Linux, and mobile.

A collection of notes in Obsidian is called a vault, which is simply a normal folder of Markdown (.md) files on disk. The core idea is linking: you connect notes with double-square-bracket wikilinks such as [[Prompt Engineering]] and add #tags, building your own personal Wikipedia. Every note automatically tracks its backlinks (the other notes that point to it), so you can see how ideas relate. This link-everything model is what makes Obsidian a knowledge base rather than a folder of isolated documents.

Obsidian ships several ways to see your thinking. The Graph view draws an interactive map of the links between your notes so you can spot hidden patterns and clusters. Canvas is an infinite whiteboard for researching, brainstorming, diagramming, and laying out notes, images, and web pages spatially. Daily notes support journaling, and a built-in Web Clipper saves articles from your browser straight into the vault.

The app is shaped by thousands of community plugins and themes plus an open API, so you can tailor it to your own workflow. Popular examples include Calendar (a view of daily notes), Kanban (Markdown-backed boards), Dataview (advanced queries over your notes), Outliner, and Tasks (track to-dos across the whole vault). This extensibility is why Obsidian adapts to students, writers, engineers, and researchers alike.

Two optional paid services sit on top of the free app, and both preserve privacy. Obsidian Sync gives end-to-end-encrypted access to your notes on any device, with one year of version history per note, selective sync, and team collaboration. Obsidian Publish turns chosen notes into a fast online wiki, documentation site, or digital garden with themes, custom domains, and password protection. Neither is required — the core app, your files, and all plugins work entirely offline.

Obsidian's values line up with TPEE's offline-first philosophy: local storage, open file formats, no account required, and no telemetry. That is why it was chosen as the documentation hub for this project. Meeting notes, implementation plans, user manuals, and prompt-engineering research all live as Markdown that you fully control.

How this relates to TPEE: Obsidian is the second half of the project's standard tandem with Graphify (lesson 79). After Graphify rebuilds the project knowledge graph, you run `graphify export obsidian --dir <vault-folder>` to write the graph as a set of linked Markdown notes plus a graph.canvas file, then open that folder in Obsidian. You can then click through TPEE's architecture — modules, communities, and god nodes — as an interactive map. The current TPEE vault lives at E:\Obsidian_On_Laptop_20\Laptop_20_Brain with the graph in a .graphify_TPEE subfolder. As always, Obsidian and Graphify are external tools; tpee.exe itself remains fully offline, makes no network calls, and runs no MCP server.

Check yourself