# Fabric Tmdl Api

> Use for the Fabric Semantic Model Definition API — createItemWithDefinition / getDefinition / updateDefinition. Covers the two-audience rule (Fabric API for definitions, Power BI API for refresh/data sources/permissions), why updateDefinition MUST include ALL parts (modified and unmodified) or they're deleted, why you NEVER include .platform in definition payloads, base64 encoding requirement, LR…

- **Type:** Skill
- **Install:** `agentstack add skill-wardawgmalvicious-claude-config-fabric-tmdl-api`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [wardawgmalvicious](https://agentstack.voostack.com/s/wardawgmalvicious)
- **Installs:** 0
- **Category:** [Databases](https://agentstack.voostack.com/c/databases)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [wardawgmalvicious](https://github.com/wardawgmalvicious)
- **Source:** https://github.com/wardawgmalvicious/claude-config/tree/main/skills/fabric-tmdl-api

## Install

```sh
agentstack add skill-wardawgmalvicious-claude-config-fabric-tmdl-api
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Semantic Model Definition API rules

- **Two audiences**: Fabric API (`api.fabric.microsoft.com`) for CRUD on definitions; Power BI API (`analysis.windows.net/powerbi/api`) for refresh, data sources, permissions
- **`updateDefinition` must include ALL parts** — modified AND unmodified. The API replaces the entire definition; omitting parts deletes them.
- **Never include `.platform`** in `updateDefinition` payloads — it is Git integration metadata and causes errors
- **Base64-encode all TMDL content** in definition payloads
- **`getDefinition` is a POST** (not GET) — requires `--body '{}'`
- **Poll LRO to completion** — `createItemWithDefinition`, `getDefinition`, and `updateDefinition` return 202

## Required TMDL Parts

| Part Path | Content |
|---|---|
| `definition.pbism` | Semantic model connection settings (JSON) |
| `definition/database.tmdl` | `database` declaration + `compatibilityLevel: 1702` |
| `definition/model.tmdl` | Model properties + `ref` declarations for tables/roles/etc. |
| `definition/tables/.tmdl` | Per-table: measures, columns, partitions |

**Critical**: `database.tmdl` MUST start with `database` object declaration, not bare properties. Bare `compatibilityLevel:` causes `InvalidLineType: Property!` errors.

## model.tmdl Required Properties

```tmdl
model Model
 culture: en-US
 defaultPowerBIDataSourceVersion: powerBI_V3
 discourageImplicitMeasures
```

`defaultPowerBIDataSourceVersion: powerBI_V3` is required for Import-mode models. Without it: `Import from JSON supported for V3 models only`.

## Direct Lake Configuration

- ALL partitions must use `EntityPartitionSource` — no M/Power Query
- A named expression pointing to the Lakehouse/Warehouse must be defined before tables:

  ```tmdl
  expression DL_Lakehouse =
      let
          Source = AzureStorage.DataLake("https://onelake.dfs.fabric.microsoft.com//", [HierarchicalNavigation=true])
      in
          Source
  ```

- Each table partition references the expression:

  ```tmdl
  partition Sales = entity
      mode: directLake
      source
          entityName: Sales
          schemaName: dbo
          expressionSource: DL_Lakehouse
  ```

- `dataType: binary` columns are NOT supported in Direct Lake
- Columns map directly via `sourceColumn` — no transforms
- **Calculated columns / tables (April 2026 preview)**: Direct Lake on **OneLake** now supports unmaterialized calculated columns (and calculated tables that reference them). Direct Lake on **SQL** still does not. User-context-aware DAX (`USERCULTURE`, `USERPRINCIPALNAME`, `CUSTOMDATA`, etc.) requires `expressionContext: userContext` on the column. See fabric-tmdl REFERENCE for the storage-mode × Expression-Context support matrix.

## Reference

- Microsoft Learn: [Item definition overview (Fabric REST)](https://learn.microsoft.com/rest/api/fabric/articles/item-management/definitions/item-definition-overview)
- Microsoft Learn: [SemanticModel definition envelope](https://learn.microsoft.com/rest/api/fabric/articles/item-management/definitions/semantic-model-definition)
- Microsoft Learn: [Develop Direct Lake semantic models (TMDL partition mode)](https://learn.microsoft.com/fabric/fundamentals/direct-lake-develop)
- Comprehensive MS Learn link bundle (definition envelope / REST CRUD / TMDL language / required parts / Direct Lake configuration / refresh APIs): [references/REFERENCE.md](references/REFERENCE.md)

## See also

- fabric-rest-api skill — LRO polling pattern, runtime item ID vs logicalId
- fabric-auth skill — Fabric vs Power BI audience selection
- fabric-cli skill — `fab export` / `fab import` wrap these APIs

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [wardawgmalvicious](https://github.com/wardawgmalvicious)
- **Source:** [wardawgmalvicious/claude-config](https://github.com/wardawgmalvicious/claude-config)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-wardawgmalvicious-claude-config-fabric-tmdl-api
- Seller: https://agentstack.voostack.com/s/wardawgmalvicious
- Browse the marketplace: https://agentstack.voostack.com/browse

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