Skills and instructions

Skills and Skill Studio

A skill is your method as files: a SKILL.md that states when and how to work, plus any reference files and scripts it leans on. Package your method into reusable skills, instruction sets the Expert loads when a task calls for them, drawing on the knowledge you attached. Already built a skill in Claude Code you keep reusing? Zip it, upload it, and seal it behind an endpoint you can list.

At least one skill is typically expected, and there are three ways to make one. Editing a skill attached to a published Expert does not change what buyers get until you re-publish; the Expert shows an Update ready badge.

Upload a skill.zip

Zip a folder with SKILL.md at its root. The frontmatter needs exactly two fields:

---
name: market-sizing
description: Size a market bottom-up from real comparables.
---
1. Segment the customer base.
2. Price each segment from comparables.

Caps: 200 files and 20 MB compressed per zip. Skills you find in the wild (a GitHub repo, a gist, an agent-skills collection) pack the same way: put SKILL.md at the top level, check its name and description fields exist, zip the folder, upload. If the frontmatter is missing either field, the upload tells you exactly which.

Or author it in Skill Studio

Describe the method in chat and the Studio drafts the files with you, on the included default model. It stages a draft you can edit file by file, and you can leave and resume. Published skills get an Improve with AI door later: the Studio forks a draft, you iterate, and applying it updates the skill in place.

Working with files

A skill is a folder, so it can carry more than SKILL.md. Put deterministic code in a scripts/ folder and extra material in references/. The bundled scripts are exactly what run in the sandbox as code tools when the expert needs precise, repeatable work; the references are there for the method to read, not to execute.

If your skill runs code

Executable tool files are Python only. They can use the standard library plus numpy, pandas, matplotlib, pypdf, Pillow, cryptography (hashing, signatures, encryption, certificates), and psutil, and reach the network only through domains you declare. No raw sockets, no subprocess, no installing packages. Each run happens in an isolated sandbox with no path back to your machine or the buyer's. The publish inspection enforces all of this, so a zip that breaks a rule is rejected with the exact reason.

How code tools run and the sandbox limits are documented in full.

System instructions

Your system instructions encode how you work: the glue that tells the Expert how to wield its skills and knowledge. Buyers never see them, so be as detailed and proprietary as you like. 200 characters is the floor, and Generate with AI drafts a first version from your profile on your own key.

The platform auto-wraps your instructions in a data-stewardship floor and an anti-extraction guard, and both take precedence over the persona.