version: "1.0.0" name: powerbi-dax description: Execute and validate DAX queries and expressions against a connected Power BI Desktop model via powerbi-agent. Invoke when the user mentions DAX, asks to run a query, test a formula, use EVALUATE / CALCULATE / SUMMARIZECOLUMNS, or validate an expression before saving as a measure. Use when the user mentions: Activate when the user wants to run a DAX query, test a DAX expression, validate syntax, explore model data via DAX, or aggregate values from the connected Power BI Desktop model.. license: MIT

Skill: Run and Validate DAX

Trigger

Activate when the user wants to run a DAX query, test a DAX expression, validate syntax, explore model data via DAX, or aggregate values from the connected Power BI Desktop model.

Prerequisites

Must have an active connection — run pbi-agent connect first if DAX commands fail with "no connection".

Commands

# Run a DAX query (default table output)
pbi-agent dax query "EVALUATE TOPN(10, Sales)"
 
# Pick output format
pbi-agent dax query "EVALUATE VALUES('Product'[Category])" --format json
pbi-agent dax query "EVALUATE Sales" --format csv
 
# Constrain to a specific table context
pbi-agent dax query "CALCULATE(SUM(Sales[Amount]))" --table Sales
 
# Pin the SSAS port (skip auto-detect)
pbi-agent dax query "EVALUATE INFO.TABLES()" --port 56123
 
# Validate an expression without executing
pbi-agent dax validate "CALCULATE(SUM(Sales[Amount]), YEAR(Sales[Date])=2024)"

Shell Quoting Notes

Multi-line DAX (VAR / RETURN) passed as a shell argument loses line breaks and breaks parsing. For multi-line expressions:

• Prefer inline single-expression form: DIVIDE([A] - [B], [B]) instead of VAR x = [A] VAR y = [B] RETURN ...
• If VAR/RETURN is required, test the single-line collapsed form first (VAR x = ... RETURN ... on one line — DAX accepts whitespace separators)

Common Exploration Patterns

# Inventory the model
pbi-agent dax query "EVALUATE INFO.TABLES()"
pbi-agent dax query "EVALUATE INFO.MEASURES()"
pbi-agent dax query "EVALUATE INFO.RELATIONSHIPS()"
 
# Preview a table
pbi-agent dax query "EVALUATE TOPN(10, Sales)"
 
# Row count
pbi-agent dax query "EVALUATE ROW(\"Count\", COUNTROWS(Sales))"
 
# Group-by aggregation
pbi-agent dax query "EVALUATE SUMMARIZECOLUMNS(Products[Category], \"Total\", SUM(Sales[Amount]))"

Common Failures

• "No active connection" → run pbi-agent connect
• Syntax error on VAR/RETURN → collapse to single-line DIVIDE / inline form, or test with pbi-agent dax validate first
• Table not found → run pbi-agent model tables to verify the exact name (case-sensitive)