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CSA Loom — the Microsoft Fabric experience for Azure tenants where Fabric isn't yet available: lakehouses, warehouses, notebooks, semantic models, Activator rules, Data Agents, across Commercial, GCC, GCC-High, and DoD IL5

semantic-model — parity with Power BI semantic model (dataset)

Source UI: Power BI dataset settings + model view — https://learn.microsoft.com/power-bi/connect-data/refresh-scheduled-refresh REST: https://learn.microsoft.com/rest/api/power-bi/datasets Editor: apps/fiab-console/lib/editors/phase3-editors.tsx -> SemanticModelEditor

Power BI feature inventory

# Capability Where in Power BI
1 Dataset list + select Workspace content list
2 Tables + columns Model view
3 Relationships Model view
4 Measures (author DAX) Model view -> New measure
5 Refresh now Dataset -> Refresh now
6 Refresh history Dataset settings -> Refresh history
7 Scheduled refresh (enable, days, times, tz, notify) Dataset settings -> Scheduled refresh
8 Take over dataset Dataset settings -> Take over
9 Row-level security (RLS) roles Model -> Manage roles
10 Open in Power BI More options
11 Build a model (tables, columns, measures, relationships) New semantic model / model authoring

Loom coverage

# Status Notes
1 built /api/items/semantic-model list (groupIds), auto-select first
2 built Tables tab from GET /datasets/{id}/tables
3 built (NEW) Relationships tab now renders real GET /datasets/{id}/relationships (listDatasetRelationships) — from/to table+column + cross-filter. Was a static "v2.2" stub
4 built Measures tab — Monaco DAX editor + Validate via POST /measures (executeQueries DEFINE MEASURE probe). Persistence on imported models is XMLA-only, disclosed; push-dataset measures are written via the Build-model tab
5 built Refresh dataset -> POST /semantic-model/[id]/refresh
6 built Refresh history tab from GET /semantic-model/[id]/refreshes
7 built Config tab — enable Switch, day buttons, times, timezone, notify; Apply -> PATCH /semantic-model/[id]/refresh-schedule (real PBI PATCH refreshSchedule)
8 built Take over dataset -> POST /semantic-model/[id]/take-over (Default.TakeOver)
9 honest-gate RLS role authoring is XMLA/Desktop only; warning MessageBar names LOOM_POWERBI_XMLA_ENDPOINT + Open in Power BI; surfaces isEffectiveIdentityRolesRequired
10 built Open in Power BI from ribbon
11 built (NEW) Build-model tab — add tables, typed columns (String/Int64/Double/Decimal/Boolean/DateTime), DAX measures, and relationships, then Create model -> POST /api/items/semantic-model/build -> createPushDataset (Power BI Push Datasets REST). Real model authoring without XMLA

Backend per control

  • Build model -> POST /groups/{ws}/datasets (createPushDataset) + POST /datasets/{id}/tables/{name}/rows (postPushRows).
  • Relationships -> GET /groups/{ws}/datasets/{id}/relationships (listDatasetRelationships).
  • Schedule read/write -> GET / PATCH /groups/{ws}/datasets/{id}/refreshSchedule (getRefreshSchedule / patchRefreshSchedule).
  • Take over -> POST /groups/{ws}/datasets/{id}/Default.TakeOver (takeOverDataset).
  • Refresh -> POST /datasets/{id}/refreshes; history -> GET /datasets/{id}/refreshes.
  • DAX validate -> POST /datasets/{id}/executeQueries.

Honest gates

  • Writing measures/tables INTO an imported or Direct Lake model requires the XMLA endpoint (Premium/Fabric capacity) or Power BI Desktop — disclosed via a MessageBar naming LOOM_POWERBI_XMLA_ENDPOINT. The push-dataset Build-model path IS the supported REST authoring route and works without XMLA.
  • RLS role authoring is XMLA/Desktop only; disclosed via MessageBar. The surface still renders fully.

Grade: A — model building (push dataset), relationships read, scheduled-refresh edit, take-over, and DAX validate are all real REST; imported-model XMLA writes honestly gated. Tests: lib/azure/tests/powerbi-client-parity.test.ts, app/api/items/tests/model-builder-routes.test.ts, app/api/items/tests/powerbi-parity-routes.test.ts.

Per-cloud notes (Power BI opt-in path)

When LOOM_BI_BACKEND=powerbi is set, the Power BI REST (/v1.0/myorg) path applies and works with LOOM_DEFAULT_FABRIC_WORKSPACE unset. The sovereign endpoint is resolved by cloud-endpoints.ts.

Cloud Power BI REST host Notes
Commercial api.powerbi.com Full coverage. List/tables/relationships/measures-validate/refresh/history/schedule/take-over/build-model all work.
GCC api.powerbigov.us Datasets, refresh, history, scheduled refresh, take-over, and push-dataset build all work (pure Power BI REST). Endorsement reads via Fabric Items REST may be unavailable (Fabric APIs are not offered in GCC) — disclosed via the same honest 401/403 gate.
GCC-High / IL4 api.high.powerbigov.us Full coverage; F-SKU + XMLA available, so imported-model writes are reachable when LOOM_POWERBI_XMLA_ENDPOINT is set.
DoD / IL5 api.mil.powerbigov.us Full coverage; F-SKU + XMLA available.

Azure-native backend — Azure Analysis Services (AAS)

Per .claude/rules/no-fabric-dependency.md the default semantic-model backend is Azure Analysis Services, not Power BI. Power BI is opt-in (LOOM_BI_BACKEND=powerbi). When NEXT_PUBLIC_LOOM_BI_BACKEND=aas (bicep sets this whenever aas.bicep is deployed) SemanticModelEditor renders the AasSemanticModelPanel; the refresh routes dispatch to AAS by default (app/api/items/semantic-model/_lib/bi-backend.ts).

Source UI: AAS server in the Azure portal + the async-refresh REST API — https://learn.microsoft.com/analysis-services/azure-analysis-services/analysis-services-async-refresh

Client: apps/fiab-console/lib/azure/aas-client.ts Endpoints: cloud-endpoints.getAasSuffix() / aasScope() (sovereign-aware).

# Capability Status Backend per control
1 Database list + select built ARM GET …/servers/{name}/databases (api 2017-08-01) → aas-databases route
2 Storage mode (Import / DirectQuery / Hybrid) built properties.model.storageMode from the same ARM call; Storage-mode tab badge
3 Refresh now (real refresh id) built AAS REST POST …/models/{db}/refreshes → refresh id from the Location header → [id]/refresh route
4 Refresh history (last 30 days) built AAS REST GET …/models/{db}/refreshes → [id]/refreshes route
5 Scheduled refresh (enable, days, times, tz, notify) built persisted as the loom-refresh-schedule ARM tag on the server (PATCH/GET …/servers/{name}) → [id]/refresh-schedule route
6 TMSL command (createOrReplace / alter / refresh) built XMLA POST …/servers/{name}/xmla (SOAP Execute) via command(tmslJson)
7 Storage-mode change honest-disclosure a model operation — use the XMLA endpoint (SSMS / Tabular Editor) or the REST createOrReplace TMSL command; the Storage-mode tab discloses this. No empty tab

Honest gates

  • When LOOM_AAS_SERVER_NAME / LOOM_AAS_REGION (etc.) are unset the aas-databases route 503s with { ok:false, gate } and the editor renders a Fluent intent="warning" MessageBar naming the exact env vars + the bicep module (platform/fiab/bicep/modules/admin-plane/aas.bicep). No Microsoft Fabric / Power BI workspace is ever required.

Bicep + bootstrap sync

  • aas.bicep provisions an AAS Standard (S1) server, adds the Console UAMI as server administrator (app:{clientId}@{tenantId}) for the refresh REST API, grants it Reader for ARM reads, and wires diagnostics to the LAW.
  • main.bicep wires LOOM_AAS_SERVER_NAME / LOOM_AAS_REGION from the module outputs and sets NEXT_PUBLIC_LOOM_BI_BACKEND / LOOM_BI_BACKEND to aas.

Per-cloud

Commercial / GCC GCC-High / IL5 DoD
AAS data-plane suffix asazure.windows.net asazure.usgovcloudapi.net gov suffix (override LOOM_AAS_DATA_PLANE_SUFFIX)
AAS auth audience https://*.asazure.windows.net/.default https://*.asazure.usgovcloudapi.net/.default derived from suffix
ARM base management.azure.com management.usgovcloudapi.net management.azure.microsoft.scloud

Tests: lib/azure/__tests__/aas-endpoints.test.ts (suffix + scope per cloud), lib/azure/__tests__/bi-backend-selector.test.ts (backend dispatch).