The skill that fixes extension errors before you hit them.

A coding agent writes a Tableau extension fast, then loses twenty minutes to the same handful of errors: a manifest that will not load, an iframe Tableau sandboxes into silence, an API call that needed a permission nobody declared. This SKILL.md bakes the fixes in, so the errors never happen.

• The .trex manifest rules, for both kinds of extension: dashboard and viz, with separate dev and prod manifests done right from the start.
• The Extensions API patterns that work: reading worksheet data, settings, configure dialogs, encodings.
• The common build errors, each with its fix, in the agent's head before the first line of code.
• Local dev and hosting, wired the way Tableau expects.

"The new skill was great. I went from zero to a working dashboard in one initial prompt. I liked some of the standards that were baked in without having to discover them throughout, like creating 2 manifest.trex files for dev and prod."

Michael McCusker, Tableau Tech Lead

"This week I built a viz extension with custom mark types using Eric Summers' Tableau Extensions skill. I gave it one prompt. It built a working extension. I loaded it into Tableau, tested it, and it worked. That was it: one prompt, no error hunting, no second try. The skill did the building. I described what I wanted, and it handled the rest."

Calvin Nguyen, Analytics and Informatics Section Manager, Tableau Certified Architect

See the original post on LinkedIn ↗

The file arrives attached as SKILL.md, ready to drop into .claude/skills/tableau-extensions/ or hand to whatever agent you use. Curious what we store? Your data, plainly.

Want to see one run before you install anything? Build a viz extension in the Studio, in your browser, no account: pick a chart, drop your fields, download a working extension.