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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

dataflow — parity with the Fabric Dataflow Gen2 editor

Comparative positioning note

This document is written from the perspective of Microsoft Azure, Cloud Scale Analytics, and CSA Loom. Any description of third-party or competing products, services, pricing, or capabilities is derived from publicly available documentation and sources believed accurate at the time of writing, and is provided for general comparison only. We do not claim expertise in, or authority over, any non-Microsoft product or service; the respective vendor's official documentation is the authoritative source for their offerings, which may change over time. Nothing here is intended to disparage any vendor — where a competing product has genuine advantages, we aim to note them honestly. Verify all third-party details against the vendor's current official documentation before making decisions.

rev.2 (2026-06-06) — rewritten against current code. The 2026-05-26 capture said "Loom has Cosmos persistence + 503 Refresh not yet wired." That is stale: DataflowGen2Editor (apps/fiab-console/lib/editors/dataflow-gen2-editor.tsx) is wired to live Fabric Items REST including a real Refresh job. This doc is the honest, feature-by-feature comparison — and it is candid that a full Power Query designer is not built (the editor is a Script + Diagram editor, not the Power Query ribbon experience).

Source UI: Fabric Dataflow Gen2 (Power Query Online). Inventory grounded in Microsoft Learn: https://learn.microsoft.com/fabric/data-factory/dataflows-gen2-overview.

Backend reality. Dataflows are managed as Fabric items + a base64 definition (mashup.pq / queryMetadata.json); Refresh triggers a real Refresh job instance on the item. This is the one item whose Gen2 authoring surface is genuinely Fabric/Power-Query-Online; the Loom editor edits the M definition and dispatches Refresh against the Fabric Items API. No mock data — list/detail/save/refresh hit Fabric REST and surface 401/403 verbatim.

Loom coverage — delivered editor surface

Legend: ✅ built (full 1:1 + real backend) · ⚠️ partial / honest-gate.

Fabric capability Loom Backend (real REST)
Workspace picker + dataflow tree (left rail) ✅ useWorkspaces + Tree GET /api/loom/workspaces, GET /api/items/dataflow?workspaceId=
Create dataflow (dialog) ✅ New POST /api/items/dataflow
Delete dataflow (confirm) ✅ DELETE /api/items/dataflow/[id]
Script tab — Power Query M (mashup.pq/.m) or definition JSON in Monaco ✅ MonacoTextarea (M → plaintext, else JSON) GET/PUT /api/items/dataflow/[id]
Diagram tab — visual projection of the M queries (steps + dependencies) ✅ DataflowDiagram parses M into a visual graph; editable parses mashup.pq; PUT on Save
Refresh now → Fabric Refresh job ✅ ribbon + button POST /api/items/dataflow/[id]/refresh (Fabric Items jobs/instances)
Save (PUT InlineBase64 definition) / Ctrl+S ✅ ribbon + keyboard PUT /api/items/dataflow/[id]
Refresh list ✅ button GET /api/items/dataflow?workspaceId=
Unsaved (dirty) badge + part-path label (mashup.pq / queryMetadata.json) ✅ from definition.parts
Save/Refresh status line (timestamps, queued) ✅ info MessageBar from responses
Errors surface verbatim (no fabricated success) ✅ MessageBar intent="error" n/a
Fabric / workspace not reachable ⚠️ honest-gate — MessageBar "Fabric not reachable" with the 401/403 + hint; the editor still renders n/a
Non-.pq/.m definition part on the Diagram tab ⚠️ honest-gate — MessageBar "edit it on the Script tab" (the diagram only projects M) n/a
No dataflow selected yet ⚠️ honest-gate — info MessageBar: design now, pick/create to Save/Refresh n/a

Every row above is ✅ or an honest ⚠️ gate — zero stub banners, zero dead controls. The 503 "Refresh not yet wired" from the old capture is gone; Refresh dispatches a real Fabric job.

Backend per control (real REST, no mocks)

  • List / detail / create / save / delete: app/api/items/dataflow[/[id]]/route.ts → Fabric Items REST (/workspaces/{ws}/items, definition get/update).
  • Refresh: app/api/items/dataflow/[id]/refresh/route.ts → Fabric Items POST /workspaces/{ws}/items/{id}/jobs/instances.
  • Diagram projection: lib/components/pipeline/dataflow-diagram.tsx (parses M, no backend).
  • Auth: Console UAMI SP authorized in the Fabric tenant + added to the target workspace; 401/403 surfaced verbatim.

Beyond this editor — full Power Query Online capabilities not yet built (honest)

The Fabric Dataflow Gen2 editor is the full Power Query Online experience. Loom ships a Script + best-effort Diagram editor over the same definition, not the Power Query ribbon. These are genuinely absent (tracked, not claimed):

Fabric capability Status
Power Query ribbon (Home / Add Column / Transform / View / Help, 300+ transforms) ❌ not built
100+ connector "Get Data" gallery ❌ not built
Queries pane (left) with right-click operations ❌ not built
Applied Steps pane (right) ❌ not built
Data Preview grid (typed columns, row count, filter/sort) ❌ not built
Schema view / column profiling + data-quality metrics ❌ not built
Refresh History pane ❌ not built — Refresh queues but history is not surfaced
AI Prompt Column / Copilot NL assistance ❌ not built
Scheduled refreshes UI ❌ not built
Parameters / Variable library ❌ not built
Data destinations config (Azure SQL / ADX / ADLS / Lakehouse / Warehouse) ❌ not built

Honest grade: this is a C-grade authoring surface for Gen2 — a real M editor + diagram + live Refresh, short of the Power Query designer. It is listed here so no reader mistakes it for full Power Query Online parity.

Bicep / env sync

  • This editor uses the Fabric Items API (an opt-in Fabric path); it requires a workspace the Console UAMI can reach, named via LOOM_DEFAULT_FABRIC_WORKSPACE / the workspace picker. Per no-fabric-dependency.md, dataflow Gen2's Azure- native equivalent for ETL is the data-pipeline (ADF/Synapse) item, which is the default path for codeless transformation when no Fabric workspace exists.
  • No new Azure resource or env var is introduced by the dataflow editor; it consumes the existing Fabric workspace wiring. Adding Bicep for the un-built Power Query surfaces above before the code exists would be dead config per no-vaporware.md.

Verification

Per no-vaporware.md: list/detail/save/refresh hit real Fabric REST; Refresh queues a real job; the unreachable / non-M-part / no-selection states are honest gates. Live side-by-side against Power Query Online confirms the gap rows above.