My Preferred Way to Use AI Inside Obsidian
The best thing about Obsidian’s “File over App” philosophy is that you don’t need any special support from the app to manage your content.
You can open the vault folder, or even a single file, in an AI agent or an agentic IDE and start editing right away.
In fact, half the time, that is the way I work with my notes in Obsidian while using an AI agent.
However, sometimes, while working on the content, I like to see my markdown rendered within Obsidian with my preferred theme and other visual customizations like dataview and other plugin outputs.
That’s when I prefer chatting with an agent alongside the content.
I tried a few options, including Smart Connections. But most of them are read-only interfaces. Another downside is that many of them require wrangling API keys, while the cheaper way to use AI is often through heavily subsidized monthly plans. (Granted, a lot of those subsidies are now going away.)
I finally found a plugin which can work with Codex and Claude subscriptions - The Obsidian Agent Client. This plugin works by communicating with the local CLI agent via the Agent Client Protocol (ACP), a protocol developed by the builders of the Zed editor.
Installation
The plugin unfortunately is not available directly in the community plugins directory and so cannot be installed from within Obsidian itself. The way I do it, is to instead install the BRAT plugin, and within the config of BRAT, add the repository of the plugin I want to install.
Update: It seems like the plugin is now available in the community plugins list itself, no BRAT required.
Configuration
There are only three things to configure in this plugin:
- Which AI agent to use: I used to choose Claude Code here. Now I choose Codex instead.
- Path to Node.js: I install it via Homebrew, so I point the plugin to that path.
- Path to the ACP plugin: I also use the Homebrew path here, since the ACP plugins for Claude and Codex are available there and that makes updates easy.
Usage
Once it is set up, I can click the Agent Client icon in the sidebar to bring up the side panel whenever I want.
For Codex, I open a session and refer to the note I want to work on using @. The current note is automatically selected, and from there I have access to whatever I already have access to in Codex.
Mostly. Not all the Codex features are available via the ACP interface. For example, till recently, you could not paste images, and I was delighted when that got added.
What do I use it for?
I mostly use it for refactoring my notes and keeping their formatting and metadata consistent. Codex recently helped me convert a large batch of notes about my subscription services into the new Obsidian base format.
I also use it for fact-checking notes and generating working examples for code and system-related topics.
It can help with diagrams too. Mermaid works best, since it is mostly text. Excalidraw can also work for simple diagrams, but it can use up a lot of tokens if you are not careful.
Use official skills
Even outside this Obsidian plugin, Codex, Claude Code, and other agents work better with Obsidian if you give them a few good skills. Kepano’s skills repository has some useful ones that help with common note-taking workflows.