coop-dax-review 0.1.0

Offline, advisory DAX/model standards linter for Power BI semantic models: parses TMDL/.bim, checks measures and model structure against the team's DAX standards, and reports anything that doesn't match. Human report + machine JSON for the company agent. Never edits or blocks.

coop-dax-review

Offline, advisory DAX/model standards linter for our Power BI semantic models. It parses TMDL (and legacy .bim) models, builds a model catalog, checks measures and model structure against docs/standards.md (our DAX standards + Microsoft/Tabular best practices), and surfaces anything that doesn't match. It never edits or blocks — it only reports. Two outputs: a human console report and machine JSON for the company analytics agent.

Sibling tool to coop-sql-review — same architecture and contracts.

Install

pipx install coop-dax-review        # once on PyPI

Use pipx, not system pip, so the tool stays isolated from other CLIs (ms-fabric-cli, azure-cli) it might otherwise fight over shared pins. For local development:

python -m venv .venv && .venv/bin/pip install -e ".[dev]"

Usage

coop-dax-review check [MODEL_PATHS...] [--format text|json] [--min-severity error|warning|info] [--strict]
coop-dax-review rules                 # list every rule (id, severity, tier, agent?)
coop-dax-review --version

• MODEL_PATHS point at a PBIP/TMDL model folder (*.SemanticModel/definition/...), any folder of .tmdl files, or a legacy .bim file. Directories are searched recursively; defaults to ..
• Advisory: exit code is always 0. --strict is the opt-in CI gate — exit 2 when any finding remains at/above --min-severity.
• --standards <path> overrides the bundled standards (e.g. point it at a canonical company standards file). Its sha256 travels in the JSON so the agent knows which standards a report used.
• A rules.yml beside the standards file (or --config) can disable rules / override severities with no rebuild.

coop-dax-review check ./MyModel.SemanticModel
coop-dax-review check . --format json --strict --min-severity warning

What it checks

Run coop-dax-review rules for the live list. Deterministic rules (reported as findings):

Rule	§	Sev	Flags
DAX-MEASURE-CATEGORY	1	warning	measure not named [Category: Name]
DAX-MEASURE-NOT-PREFIXED	1	warning	Table[X] where X is a measure (measures take no prefix)
DAX-COLUMN-PREFIXED	1	warning	bare [X] where X is a column (columns need Table[X])
DAX-VAR-RETURN	2	info	non-trivial measure with no VAR/RETURN structure
DAX-NO-NESTED-CALCULATE	3	warning	CALCULATE nested inside CALCULATE
DAX-FILTER-TABLE-IN-CALCULATE	4	warning	FILTER(<table>, <col> = ...) where a plain column filter suffices
DAX-SNOWFLAKE	6	info	a table with relationships chained through it (snowflake link)
DAX-BIDI-RELATIONSHIP	7	warning	a bidirectional cross-filter relationship
DAX-MARKED-DATE-TABLE	8	warning	time-intelligence used but no marked Date table
DAX-MEASURE-IN-ITERATOR	9	info	a measure referenced inside a row iterator (hidden context transition)
DAX-COMPLEX-NO-HEADER	12	info	a complex measure (≥3 VARs) without a /* ... */ header
DAX-DIRECTLAKE-NO-CALC-COL	13	warning	a calculated column in a Direct Lake model
DAX-USE-DIVIDE	14	warning	the / operator where DIVIDE() should be used
DAX-FORMAT-STRING	15	warning	a measure with no explicit formatString
DAX-NO-FLOAT-KEYS	16	info	a relationship key column typed double
DAX-HIDE-FK-COLUMNS	17	info	a visible foreign-key (relationship) column
DAX-KEY-SUMMARIZEBY-NONE	18	info	a numeric key column that auto-aggregates (summarizeBy ≠ none)
DAX-DISPLAY-FOLDERS	19	info	a measure-heavy table with no display folders

Agent-judgment rules — the tool detects the construct but emits to the JSON agent_review list (never an auto-finding), because the call needs intent the linter can't infer:

Rule	§	Judges
DAX-KEEPFILTERS-NEEDED	5	whether a CALCULATE boolean filter needs KEEPFILTERS
DAX-STAR-SCHEMA	6	whether a snowflake chain should be flattened to a star
DAX-CONTEXT-TRANSITION	9	whether an iterator's context transition is intended/correct
DAX-SIMPLE-FUNCTIONS	10	whether a CALCULATE-heavy measure could use simpler functions
DAX-VALIDATION	11	whether the §11 validation checklist was run for a non-trivial measure
DAX-IMPLICIT-MEASURE	20	whether a visible auto-aggregating numeric column should become an explicit measure

See RULES.md for the full taxonomy. docs/standards.md §14–§20 are adopted Microsoft/Tabular best practices (DIVIDE, format strings, key column types, hidden FKs, key summarizeBy, display folders, explicit measures); docs/standards-proposed-additions.md is the original candidate list.

Agent JSON contract

{
  "tool": "coop-dax-review", "version": "x.y.z",
  "standards": {"path": "...", "sha256": "..."},
  "findings": [{"rule_id":"...","severity":"warning","model":"Sales","file":"...","line":12,
                "object":"[Sales: Revenue YTD]","message":"...","standard_ref":"§3"}],
  "summary": {"error":0,"warning":2,"info":4},
  "agent_review": [{"rule_id":"...","object":"[...]","note":"...","standard_ref":"§5"}],
  "diagnostics": [{"severity":"warning","category":"parse_failed","file":"...","message":"..."}]
}

Project docs

• SPEC.md — architecture, CLI, agent contract, milestones.
• RULES.md — every standard mapped to a concrete check (deterministic vs agent-judgment).
• docs/standards.md — the canonical DAX standards the linter checks against (bundled as package data).
• CLAUDE.md — orientation for Claude Code sessions in this repo.