# Tmdl

Direct TMDL file authoring and BIM-to-TMDL conversion for semantic models in PBIP...

- Repository: https://github.com/data-goblin/power-bi-agentic-development (1079 stars)
- Category: Engineering
- License: GPL-3.0
- Last updated: 2026-10-30
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add data-goblin/power-bi-agentic-development --skill tmdl -g -a claude-code -y`
Codex: `npx skills add data-goblin/power-bi-agentic-development --skill tmdl -g -a codex -y`
Cursor: `npx skills add data-goblin/power-bi-agentic-development --skill tmdl -g -a cursor -y`
Gemini CLI: `npx skills add data-goblin/power-bi-agentic-development --skill tmdl -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add data-goblin/power-bi-agentic-development`

## Description

Direct TMDL file authoring and BIM-to-TMDL conversion for semantic models in PBIP projects. Automatically invoke when the user asks to "edit TMDL", "add a measure in TMDL", "TMDL syntax", "fix formatString", "fix summarizeBy", "TMDL indentation", "convert BIM to TMDL", "add a column description", "create a calculated column in TMDL", or mentions .tmdl file editing or BIM-to-TMDL migration.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# TMDL Authoring

Expert guidance for authoring and editing TMDL (Tabular Model Definition Language) files directly in PBIP projects.

> **This skill is a last resort.** Direct TMDL file editing lacks the validation, atomicity, and DAX query capabilities of the Tabular Editor CLI, Power BI MCP server, or the `connect-pbid` skill (TOM via PowerShell). Use those tools when available. TMDL editing is appropriate when:
>
> - Working with PBIP files in a Git repo without Power BI Desktop open
> - No Tabular Editor CLI or MCP server is installed
> - Making quick text-level fixes (descriptions, format strings, display folders) where a full tool chain is overkill
>
> Direct TMDL editing does not validate DAX syntax, check referential integrity, or verify that property values are valid. Errors will only surface when the model is next loaded in Power BI Desktop or deployed via XMLA. Use the **`pbip-validator`** agent to check TMDL files for syntax issues, indentation errors, and referential integrity before opening in PBI Desktop.

## When to Use This Skill

Activate only when the Tabular Editor CLI, Power BI MCP server, or `connect-pbid` skill are not available, and tasks involve:

- Editing `.tmdl` files directly (measures, columns, tables, relationships)
- Adding or modifying measure definitions in TMDL
- Adding descriptions to columns, measures, or tables
- Fixing `summarizeBy` or `formatString` values
- Understanding TMDL syntax rules (indentation, quoting, property ordering)
- Writing multi-line DAX in TMDL format
- Understanding the difference between `///` descriptions and `//` comments

## Critical

The rest: https://github.com/data-goblin/power-bi-agentic-development/blob/HEAD/plugins/pbip/skills/tmdl/SKILL.md