In the last post I described how I set up a local LLM and how I create purpose-built agents:

Whenever I want AI help with something specific, I make a new directory under ~/projects/ on my Air and just start working with pi. Once I’ve done what I want to do, I tell pi to record the process in an AGENTS.md. From that point on, every time I open pi in that directory it reads the file and is immediately ready to continue.

Continuing on that, I’ve started building a general library of capabilities for the agents. Pi reads a global AGENTS.md from ~/.pi/agent/AGENTS.md on startup. Mine is a symlink to a CAPABILITIES.md in a repo called agent-docs. It’s a capability index: a list of things the agent can do, each with a short description of when to reach for it and a pointer to a doc that explains how. Here’s an excerpt:

- **Studio machine** — a powerful always-on Mac you can SSH into.
  Reach for it when you need more horsepower or a stable host for a
  background service. Read @/Users/sami/projects/agent-docs/STUDIO.md.

- **exe.dev VMs** — on-demand Linux VMs with a public HTTPS proxy.
  Reach for it when you need a real Linux box or a public URL.
  Read @/Users/sami/projects/agent-docs/EXE-DEV.md.

- **Browser automation** — drive a real Chrome from the shell.
  Reach for it when you need to scrape, fill a form, or visually
  check a deployed page. Read @/Users/sami/projects/agent-docs/AGENT-BROWSER.md.

The agent doesn’t load all specific instructions upfront. It reads the index, decides whether the task matches a capability, and only then reads the relevant doc. The docs themselves are ordinary markdown: what the thing is, when to use it, how to use it. I write and update them almost exclusively with AI. agent-docs is itself a purpose-built agent for maintaining the library.

I also include a reference to CAPABILITIES.md in the AGENTS.md of individual coding projects, so project agents can reach for the same tools.

The current list has seven entries: the Studio, the local LLM, private git hosting on the Studio, exe.dev VMs, browser automation, a personal MCP server, and this blog. Adding a new one is three steps: write the doc, add a line to the index, commit.

The idea is that this compounds. Every time I set something up, I write a doc for it. The agents inherit the capability. Over time the agent should become genuinely useful across a wide range of tasks, because the infrastructure behind it keeps growing.