Skip to content
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

Eventstream — Parity gap (validator verdict 2026-05-26)

Grade: D (multiple BLOCKERs)

Validator: v2 4-phase live-browser + source-code review. Loom URL: https://loom-console-fvbbctd4eehqbkcs.b02.azurefd.net/items/eventstream/6ac04218-5bfc-47dd-b58b-df11e2bf4e80

Loom screenshot: temp/parity/eventstream-loom.png (full-page, 19150 bytes, captured live). Fabric reference screenshot: not capturable from this validator session (corporate auth blocks Fabric portal from Playwright). Reference UX captured in docs/fiab/eventstream-parity-spec.md from prior catalog phase.

Phase 1 — Fabric reference (from spec)

Three-section visual designer: drag-and-drop canvas with source → transform → destination nodes; right pane = configuration; bottom pane = test results. Source picker = 18+ types (Event Hubs, Kafka, CDC family, Fabric workspace events, Blob events, Sample data, Custom endpoint). Transform nodes = Filter, Aggregate, GroupBy, Manage fields, Join, Union, Expand, SQL operator. Destination picker = Lakehouse, Eventhouse, Activator, Custom endpoint, Derived stream, Spark Notebook.

Phase 2 — Loom under test (live)

Single textarea displaying raw JSON config:

{
  "source":   { "kind": "eventhub", "namespace": "", "name": "", "consumerGroup": "$Default" },
  "transforms": [],
  "sink":     { "kind": "kusto", "database": "loomdb-default", "table": "" }
}

Plus a warning MessageBar: "v2.1 — configuration only. Pipeline metadata is persisted to Cosmos but the Event Hubs → Kusto ingestion runtime is not yet executing. Real runtime wiring lands in v3."

Ribbon visible at top: Add source / Sample data / Filter / Aggregate / Group by / Add destination / Save / Publish. All ribbon group actions except Save resolve to declarative spec entries only — the buttons render in the chrome but have no click handler wired (verified by source: EventstreamEditor only binds load, save; the ribbon definitions in ES_RIBBON are static labels). The only working interactive controls on the body are the JSON textarea and the Save button.

Source confirmation: apps/fiab-console/lib/editors/phase3-editors.tsx lines 756-835. Editor body = <textarea className={s.monaco}> (cosmetic CSS class named monaco but it's a vanilla textarea — NOT @monaco-editor/react). No react-flow / @xyflow/react / reactflow in apps/fiab-console/package.json. No SVG canvas. No drag-and-drop. No transform graph.

Phase 3 — Side-by-side gap matrix

Fabric element Loom Severity
Visual designer canvas (drag-and-drop source / transform / destination nodes) Missing — JSON textarea only BLOCKER
Source picker dialog with 18+ source types Missing — JSON source.kind field BLOCKER
Destination picker with 6 destination types Missing — JSON sink.kind field BLOCKER
Transform node palette (Filter, Aggregate, GroupBy, Manage fields, Join, Union, Expand, SQL) Missing — append entries to transforms[] JSON BLOCKER
Test-result preview pane (live event sampling) Missing BLOCKER
Authoring error validation (red-underline) Missing MAJOR
Pause/resume controls Missing MAJOR
Apache Kafka endpoint integration view Missing MAJOR
Schema management with Schema Registry Missing MAJOR
Honest "config-only" MessageBar Present — Fluent warning bar with v3 note (positive)
Save → persists to Cosmos Present — PUT /api/items/eventstream/{id} returns 200 with config (positive)
Ribbon tab "Home" with Source/Transform/Destination/Publish groups Present but actions are no-ops MAJOR
Monaco JSON editor with schema validation Missing — plain textarea MAJOR

Phase 4 — Functional click-every-button verification

Loom control Result
GET /api/items/eventstream/{id} 200 — returns {ok:true, runtimeStatus:'config-only', config:{transforms:[]}}
PUT /api/items/eventstream/{id} body=config 200 — persists to Cosmos (verified via state machine)
Body textarea typing Updates cfgText state; JSON.parse error caught on Save
Save button Real fetch → 200, dirty cleared. PRIMARY ACTION WORKS
Ribbon: Add source / Sample data / Filter / Aggregate / Group by / Add destination / Publish No-op — buttons render but no click handler bound. BROKEN (silently dead)
MessageBar "configuration only" Rendered, accurate
No event-hub runtime to actually stream against Honest gate — accepted per no-vaporware.md

Verdict

D-grade. Multiple Phase-3 BLOCKERs (no visual canvas, no source/destination picker, no transform palette, no test-result pane). Phase-4 has silently dead ribbon buttons (Add source/Filter/Aggregate/Group by/Add destination/Publish) which is BROKEN per workflow contract.

Per no-vaporware.md and no-scaffold-claims.md: this is the JSON-spec-only state the catalog spec called out — "Visual canvas: ❌ none. New React component with react-flow or similar." That work has not been done. The JSON textarea is honest in surfacing its limitation via MessageBar, which prevents an F (vaporware) grade. But it cannot be called shipped, in parity, or A/B-grade.

Required for ≥ B grade

  1. Replace JSON textarea with react-flow (or @xyflow/react) drag-and-drop canvas.
  2. Source picker dialog with the 11 external streaming sources + 7 CDC sources + 4 Fabric event sources + 9 data sources + custom endpoint (matches Fabric).
  3. Destination picker dialog with the 6 destination types (Lakehouse, Eventhouse, Activator, Custom endpoint, Derived stream, Spark Notebook).
  4. Transform node palette: each transform = right-pane config form with type-specific fields (Filter: predicate; Aggregate: window+func+field; etc).
  5. Bind each ribbon button to its actual function. Buttons with no backend yet must show the honest "configure first" or "feature requires X" MessageBar inline.
  6. Test-result pane that samples 10 events from the configured source.

Estimated effort to reach B: 3-4 focused sessions. To A: 5-6 sessions + bicep to deploy Event Hubs namespace + Stream Analytics runtime.

Evidence

  • Live API calls executed in this validator run:
  • GET /api/items/eventstream/6ac04218-… → 200 (real Cosmos read)
  • POST /api/workspaces/de489967-…/items (created the test item) → 201
  • Source code reviewed: apps/fiab-console/lib/editors/phase3-editors.tsx lines 726-835.
  • Package check: no react-flow*, no @xyflow*, no @monaco-editor/react, no @kusto/monaco-kusto.
  • Screenshot: temp/parity/eventstream-loom.png.