Loom Data Product Template Editor — Fabric-parity spec

Captured 2026-05-26 by catalog agent. Sources: Microsoft Learn — Create and manage data products (Purview Unified Catalog), Sample setup for data governance, Get started with Microsoft Purview data governance, Use Microsoft Purview to govern Microsoft Fabric, OneLake catalog overview, Store data in Microsoft Fabric, Unified Catalog data product access policies. Cross-checked against current Loom editor at apps/fiab-console/lib/editors/data-product-editors.tsx::DataProductTemplateEditor, the curated catalog in apps/fiab-console/lib/catalog/data-product-templates.ts, and the instantiate route at app/api/items/data-product-template/[id]/instantiate/route.ts.

What it is

There is no Microsoft service explicitly called "Data Product Template". The closest Microsoft concepts are:

1. Microsoft Purview Unified Catalog data products — a Purview-governed entry in a Governance Domain that bundles data assets, business context, and access policies. Created individually OR in bulk via CSV import (preview). Has a lifecycle: draft → published → expired. Required role: Data Product Owner.
2. Fabric OneLake catalog — the discovery surface inside Fabric where workspace items + data products are browsed.
3. CSA-curated push-button templates — a Loom-original concept (not a Microsoft product). A Loom template lists a set of component item types (lakehouse, pipeline, eventhouse, vector-store, etc.) and a one-click Instantiate flow that creates each as a real Loom item in a workspace, then links them under a parent data-product-instance. This editor is the template author / catalog browser for that pattern.

The Fabric-parity target is therefore the Purview Unified Catalog data product creation + governance-domain UX combined with Loom's existing curated push-button template gallery.

UI components

Page chrome

• Title bar: catalog name + saved-state indicator
• Top toolbar: Browse library, + New template, Import CSV (bulk template authoring), Refresh

Library grid (Browse mode)

• Card grid; each card shows:
• Template display name
• Category badge (Lakehouse / Streaming / Mesh / AI-RAG / IoT / Geospatial)
• Estimated monthly cost (USD)
• Description (1-2 lines)
• Component count
• Endorsed ribbon (when marked)
• Filters: category, cost band, owner, endorsement status
• Search box (over display name, description, component slugs)

Template detail page (selected mode)

• Basic details: name, description (up to 10,000 chars per Purview), type (Master/Reference/Dataset/Operational/Analytics/Dashboard-Report), audience (optional), owner(s) — matching the Purview data product creation form
• Business details: governance domain assignment, use case (narrative of how a consumer applies the data), endorsement toggle (Mark as Endorsed)
• Components table: per-component row with label, item-type slug, description, default state (read-only JSON expander)
• Custom attributes: per-template custom-attribute editor (parity with Purview's Custom Attributes per-business-concept config)
• Access policy preview: shows the inherited governance-domain policy + any template-specific overrides (access-time limit, approval requirements, manager-approval flag, data-copy-attestation)
• References / Learn links rendered as a side panel

Instantiate dialog (per template)

• Target workspace picker (queries Loom's /api/workspaces for the signed-in user's workspaces)
• Instance display name input
• Override component defaults expandable table (per-component, override any defaultState key) — currently absent in Loom
• Pre-flight check: required Azure resources for this template + RBAC the user must hold; renders a MessageBar listing any missing capabilities
• Cost estimate banner: rough USD/month from the template plus a "this is order-of-magnitude only" disclaimer
• Spawn into workspace button — primary action; disabled until workspace + name are set

Template author / edit mode (admin-only)

• Same form fields as detail page but editable
• Add component dialog: item-type picker, label, description, defaultState JSON editor
• Reorder components drag-handle
• Bulk import flyout — download sample CSV, fill out per the documented Purview CSV schema, re-upload (templates land in draft state)
• Publish / Unpublish (set to draft) / Set to expired buttons mirroring the Purview state machine

Governance domain context (left rail)

• Tree of Governance Domains (queried from Purview) → templates assigned to each domain
• Per-domain header: data-product-owner names, glossary terms inherited, default access policy summary

What Loom has

The current DataProductTemplateEditor (apps/fiab-console/lib/editors/data-product-editors.tsx, lines 44-155) is partially functional:

• GET against /api/items/data-product-template returns the in-memory CURATED_TEMPLATES array (8 templates: modern-data-warehouse, lambda, kappa, medallion-on-databricks, iot-analytics, federated-mesh, rag-agent-platform, geospatial-pipeline) plus any custom workspace-scoped templates from Cosmos
• Library grid renders per-card with display name, category, est. cost, description, component count
• Click card → detail view with components table + back button
• Workspace + display-name inputs + Instantiate in workspace button POSTs to /api/items/data-product-template/[id]/instantiate
• Instantiate route walks template.components[] and calls createOwnedItem per component, then creates a parent data-product-instance linking them
• Result MessageBar shows created count + failure count
• Ribbon advertises Browse, Refresh, Spawn into workspace — partially wired
• Cosmos persistence of any custom (non-curated) template via the generic owned-item path
• Grade: B (production-grade) — the instantiate happy path actually runs end-to-end against real Loom items; this is the strongest of the seven editors in this batch

Gaps for parity

1. Purview governance-domain linkage absent — Purview requires a data product to live inside a published governance domain; Loom templates have no domain field, no domain-tree left rail, no domain-publish gating.
2. Data Product Owner RBAC absent — Purview enforces the Data Product Owner role for create/edit/publish; Loom uses the generic owned-item ACL.
3. Lifecycle state machine absent — Purview has draft → published → expired with Publish / Unpublish / Set to Draft / Set to Expired actions; Loom templates are always "live".
4. Bulk CSV import absent — Purview ships sample CSV download + 1000-row max bulk import; Loom doesn't.
5. Custom attributes absent — Purview's per-business-concept custom attributes (admin-configurable) are not modeled.
6. Access policy editor absent — the Purview Manage policies flyout (access-time limit, approval requirements, manager approval, data-copy attestation) is missing. This is the high-value gap because access governance is the whole point of Purview data products.
7. Endorsement toggle absent — Mark as Endorsed is a one-click promotion in Purview; not in Loom.
8. Override component defaults at instantiate-time absent — the user gets workspace + name only; the component table is read-only. For real-world use, overriding a component's region, SKU, or path is essential.
9. Pre-flight check absent — no RBAC / capability check before spawning; instantiate either succeeds or returns per-component errors after partial provisioning.
10. Description-length limit (10,000 chars per Purview) not enforced — Loom templates take any length.
11. Cost estimate is a static field — Purview doesn't have this; Loom invented it. Should be relabeled "Indicative cost — confirm in Azure Cost Management" to avoid implying SLA-quality estimation.
12. No "share to OneLake catalog" handoff — when Loom spawns Fabric items (lakehouse, eventhouse, etc.), the spawned items should also surface in the OneLake catalog with the Purview sensitivity labels from the template; Loom currently does neither.
13. No glossary-term linkage — Purview data products link to glossary terms which inherit policies; Loom has no glossary surface.
14. Audience field absent — Purview's Audience dropdown is documented; Loom doesn't capture it.

Backend mapping

Loom surface	Backing service	Notes
Curated template catalog	In-memory CURATED_TEMPLATES array in lib/catalog/data-product-templates.ts	Already wired; add new templates by appending to the array
Custom template persistence	Cosmos items container, partition data-product-template	Already wired
Template instantiation	Existing /api/items/data-product-template/[id]/instantiate walks components and calls createOwnedItem per component slug	Each child item type already has its own bicep + BFF wiring
Governance-domain linkage	Purview REST: GET /datagovernance/catalog/governanceDomains + POST /datagovernance/catalog/dataProducts body {governanceDomainId, ...}	New lib/azure/purview-catalog-client.ts wrapper
Lifecycle state machine	Same Purview REST endpoints with state: draft/published/expired	Mirrors the documented Purview state
Bulk CSV import	Client-side CSV parser → loop calls to POST /api/items/data-product-template	No new backend endpoint
Access policy editor	Purview REST: POST /datagovernance/catalog/dataProducts/{id}/accessPolicies body matches the documented schema (access-time limit, approval-required, manager-approval, data-copy-attestation)	Pattern documented in Unified Catalog data product access policies
OneLake catalog handoff	Fabric Catalog REST: POST /v1/items/discover (preview) to register a spawned item; or rely on Fabric's automatic catalog ingestion for items created in Fabric workspaces via the Fabric REST API	Loom already uses fabric-client.ts for workspace listing; extend with catalog endpoints
Endorsement	Purview REST + Fabric item endorsement (/v1/workspaces/{ws}/items/{id} PATCH endorsementStatus: Promoted/Certified)	Two separate writes; both already in the Fabric admin REST surface
Custom attributes	Purview REST GET /datagovernance/catalog/customAttributes for the schema + per-data-product values stored in the customAttributes field of the data product entity	Schema is admin-configured upstream
Glossary term linkage	Purview REST /datagovernance/catalog/terms/{id}/relations	Same client as above

Required Azure resources

• Microsoft Purview account (Loom already has one for governance scanning; needs the Unified Catalog experience enabled, which is the default for new accounts post-2024)
• At least one published Governance Domain in Purview (admin one-time bootstrap; document in docs/fiab/v3-tenant-bootstrap.md)
• Data Product Owner role assigned to the signed-in user on the target governance domain (required for create/publish per the documented permissions matrix)
• Microsoft Fabric capacity for the OneLake catalog surfacing
• AAD app permissions: Purview.Read.All + Purview.ReadWrite.All delegated; Fabric.ReadWrite.All for the catalog handoff
• No new Azure resource for the Loom-internal template catalog itself; the curated array lives in source and the custom templates live in the existing Loom Cosmos items container

Estimated effort

• Session N+1 (~3 hrs) — governance-domain left-rail tree + Purview client wrapper + add governanceDomainId to the template state + bootstrap doc updates
• Session N+2 (~3 hrs) — lifecycle state machine (draft/published/expired) + Publish/Unpublish/Set-Expired buttons + Data Product Owner role check pre-flight
• Session N+3 (~3 hrs) — Access policy editor flyout (access-time limit, approval-required, manager-approval, data-copy-attestation) wiring the Purview REST POST
• Session N+4 (~2 hrs) — Override component defaults at instantiate-time + pre-flight RBAC / capability check + endorsement toggle
• Session N+5 (~2 hrs) — Bulk CSV import (parser + loop) + custom-attributes editor + audience + glossary-term linkage
• Session N+6 (~2 hrs) — OneLake catalog handoff for Fabric-resident spawned items + sensitivity label propagation
• Session N+7 (~1 hr) — relabel cost-estimate caveat; Vitest + Playwright end-to-end UAT: instantiate the rag-agent-platform template in a clean workspace and confirm all components surface in Purview + OneLake catalog

Total: ~16 hrs across 7 sessions. Current grade: B (the strongest of the seven). Target: A+ — this editor is high-leverage because every push-button data-product spawned from here surfaces all the other editor types covered in this catalog batch.