Obsidian

• A personal knowledge base. Meeting notes, reading notes, ideas and how-tos in one place, linked to each other, searchable years later.
• Working with AI agents. Because notes are plain files, an agent such as Claude Code or Codex can read your notes for context, write summaries back, and keep a running log. See the setup tutorial linked below.
• Daily notes and tasks. One note per day for what happened and what is next, with checkboxes you can collect across the vault.
• Writing drafts. Long documents, outlines and research, with links back to the sources you used.

It is a weaker fit when you need real-time editing with a team; shared docs tools are built for that.

1. Download Obsidian from the official site and install it.
2. Create a vault. Choose Create new vault, give it a name and pick a folder. To try it with existing Markdown files, choose Open folder as vault instead.
3. Write your first notes. Make two notes and link one to the other with [[...]]. Open the second note and look at its backlinks.
4. Turn on daily notes (Settings → Core plugins → Daily notes) if you want one note per day.

For AI agents, turn on the command line tool. Obsidian 1.12 added an official CLI (command line interface) so programs, including agents, can search, read and write notes in a running Obsidian:

1. Update to the latest installer (1.12.7 or newer). An in-app update is not always enough; download the installer again if needed.
2. Go to Settings → General and turn on Command line interface.
3. Follow the prompt to register it, then restart your terminal.
4. Type obsidian help in a terminal. A list of commands means it works.

Obsidian has to be running for the CLI to work; if it is closed, the first command opens it.

In the app: write, link with [[...]], search with Ctrl/Cmd+Shift+F, and open the graph view to see how notes connect.

From a terminal (and for agents): a few everyday commands:

obsidian search query="meeting notes"
obsidian read file="Project plan"
obsidian create name="Ideas" content="# Ideas"
obsidian daily:append content="- [ ] Call the bank"
obsidian backlinks file="Project plan"

Parameters use name=value (quote values with spaces); flags such as open (open the note after creating it) take no value. file= finds a note by name like a link does; path= takes the exact path inside the vault. Without either, many commands act on the note that is open right now, so always name the note when writing.

Connecting an agent: give your agent our Obsidian skill. It tells the agent to use the official CLI first, to read before it writes, and to ask before moving or deleting notes. The beginner tutorial walks through the whole setup.

• Back up your vault. It is just a folder, so copy it somewhere safe or put it under version control (Git). Do this before you let an agent write to it.
• Deletes go to the trash by default. The CLI command delete moves a note to the trash; adding permanent skips the trash. Never let an agent use permanent without asking you.
• Community plugins run code on your computer. Install only ones you trust, and only as many as you need.
• Sync is a paid add-on. Putting a vault in a cloud folder also works, but two devices editing the same note at once can create conflicted copies.