Codex skill for editable Excalidraw diagrams

Codex
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1

Hi everyone,

I wanted to share a small original project I built while experimenting with Codex skills:

codex-excalidraw-skill

The idea was to make Codex generate diagrams that are not just static images, but real editable Excalidraw scenes. The skill creates structured .excalidraw JSON, SVG/HTML previews, ready-to-open Excalidraw Web links, and local session state so follow-up requests can modify the previous diagram instead of starting from scratch.

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I built it because I wanted a workflow closer to an interactive diagramming assistant: ask Codex for a visual, inspect the preview, open it in Excalidraw, and keep iterating. The repository includes the skill instructions, helper scripts, references, examples, and an example tactical diagram rendered in the README.

A few things the skill currently supports:

  • Natural-language requests to editable Excalidraw diagrams
  • SVG and HTML previews
  • Open-in-Excalidraw web links
  • Session-state reuse for incremental edits
  • Validation checks for unreadable text and broken scene structure
  • Specialized templates for tactical football rosters and building elevations

This is my own implementation, created through hands-on testing and iteration in Codex. I did not copy an existing skill; I used the project as a way to learn how far Codex skills can go for visual, editable artifacts.

I am sharing it here in case it helps other builders thinking about Codex skills, diagram generation, or editable AI-created artifacts.

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I would love feedback from the community, especially on:

  • How to make the skill easier for others to install and adapt
  • Better patterns for preserving manual edits across follow-up requests
  • Whether this kind of workflow should eventually become a proper MCP/widget integration

Made by Fabricio Artur.

https://www.linkedin.com/in/fartur/

2

Thanks for sharing, @Fartur.

I wonder if we should do a Skill Gallery thread like we do for images? :thinking:

This sounds like a useful skill, though.

3

Thanks, Paul.

I would definitely support that idea.

A Skill Gallery could make it much easier for builders to discover reusable skills, learn implementation patterns, and share ideas. I think we’re starting to see more people experimenting with Codex skills, and having a dedicated place to showcase them could help the community grow faster.

I’d be happy to contribute this Excalidraw skill and any future experiments as well.

5

Hello, can you transform this skill.md into a plugin of codex app so you could edit the diagrams in-place inside the UI?

6

Thanks @codex4 — great idea! I’d love the challenge of turning this into a plugin. I’ll dig into the Codex plugin structure (manifest + skills) and see what it would take to bring Excalidraw editing closer to the UI. If you have a wishlist for features or UX, I’m all ears.