DaxSAFE

Power BI AI skills and Power BI agents for Claude Code and GitHub Copilot: a plugin marketplace of Power BI skills, subagents, and hooks for semantic models, DAX, TMDL, reports, and AI dashboards. Includes Microsoft Fabric skills and Fabric agents. Weekly updates.

The instruction file, verbatim from the audited commit — this is the text the model reads, and the surface the audit's instruction layer examines. Quoted here so you can judge it without cloning anything.

---
name: dax
description: DAX performance optimization for semantic models. Automatically invoke when the user asks to "optimize DAX", "fix slow DAX", "DAX performance", "tune a measure", "debug a measure", "DAX anti-patterns", or mentions slow queries, server timings, or DAX authoring.
---

# DAX

Skills and references for writing, debugging, and optimizing DAX in semantic models.

## Optimization

For systematic DAX query performance optimization, read the workflow reference first:

**[`references/dax-performance-optimization.md`](./references/dax-performance-optimization.md)** — Tiered framework (4 tiers), phased workflow, decision guide, and error handling.

Detailed reference files (progressive disclosure — consult as directed by the workflow):

- **[`references/engine-internals.md`](./references/engine-internals.md)** — FE/SE architecture, xmSQL, compression/segments, SE fusion, trace diagnostics
- **[`references/dax-patterns.md`](./references/dax-patterns.md)** — Tier 1 DAX patterns (DAX001–DAX021) + Tier 2 query structure (QRY001–QRY004)
- **[`references/model-optimization.md`](./references/model-optimization.md)** — Tier 3 model patterns (MDL001–MDL009) + Tier 4 Direct Lake (DL001–DL002)

Trace capture and performance profiling:

- **Local models (Power BI Desktop):** Use the Tabular Editor CLI `te query` (see the [`te-cli` skill](../../../tabular-editor/skills/te-cli/)) first; as an alternative, the [`connect-pbid` skill](../../../pbi-desktop/skills/connect-pbid/) covers FE/SE timing (`performance-profiling.md`) and intermediate result inspection (`evaluateandlog-debugging.md`).
- **Remote models (Fabric Service / XMLA):** Run DAX with the Tabular Editor CLI `te query` (`-s <workspace> -d <model>`) against the workspace XMLA endpoint; see the [`te-cli` skill](../../../tabular-editor/skills/te-cli/) (tabular-editor plugin).
- **Power BI Modeling MCP:** also available for trace and query if you prefer an MCP tool; reach for it after the options above.

## Related Skills

- [`semantic-model`](../semantic-model/) — Model design, build, and auditing including DAX anti-patterns and best practices
- [`connect-pbid` (pbi-desktop plugin)](../../../pbi-desktop/skills/connect-pbid/) — Trace capture, performance profiling, EVALUATEANDLOG debugging
- [`lineage-analysis`](../lineage-analysis/) — Impact analysis before model changes

SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.

What the source does

Filesystem

none-observed

Network

none-observed

Shell

none-observed

Dependencies

pinned

Secrets in source

none-found

Findings (0)

No findings outside the package's declared scope.

Gates applied: no_behavioural_pass.