diff --git a/architecture/workspace/containers-platform.puml b/architecture/workspace/containers-platform.puml
new file mode 100644
index 0000000..ce3957e
--- /dev/null
+++ b/architecture/workspace/containers-platform.puml
@@ -0,0 +1,80 @@
+@startuml
+!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
+
+LAYOUT_WITH_LEGEND()
+
+title Kell Creations Platform - Container Diagram
+
+Person(owner, "Business Owner", "Oversees business operations, governance, and growth")
+Person(staff, "Operations Staff", "Supports production, publishing, fulfillment, and administration")
+
+System_Ext(wordpress, "WordPress", "Website and content publishing platform")
+System_Ext(n8n, "n8n", "Workflow automation and AI-enabled process orchestration")
+System_Ext(mail, "Mail Server", "Business notifications, approvals, and communications")
+System_Ext(git, "Forgejo Git", "Source control and auditable documentation history")
+System_Ext(facebook, "Facebook", "Social media publishing and engagement")
+System_Ext(instagram, "Instagram", "Social media publishing and engagement")
+System_Ext(xsocial, "X", "Social media publishing and engagement")
+
+System_Boundary(platform, "Kell Creations Platform") {
+  Container(inventory, "Inventory Application", "Web App", "Tracks materials, finished goods, stock adjustments, and availability")
+  Container(social, "Social Media Management", "Web App", "Plans campaigns, schedules content, and tracks social engagement")
+  Container(wpmanage, "WordPress Management", "Web App / Admin Service", "Manages WordPress publishing, content sync, and site administration")
+  Container(mrp, "Craft Manufacturing / MRP", "Web App", "Manages BOMs, work orders, production planning, and fulfillment preparation")
+  Container(finance, "Financial Analysis", "Web App", "Supports reporting, forecasting, and business performance analysis")
+  Container(txdb, "Transaction Database", "Database", "Stores product, order, customer, material, and transaction records")
+  Container(auth, "Authentication Service", "Shared Service", "Provides authentication and identity controls across applications")
+  Container(datarepo, "Shared Data Repository", "Shared Service", "Provides common data access patterns and shared business entities")
+  Container(api, "API Orchestrator", "API / Integration Service", "Coordinates integrations and internal service communication")
+  Container(notify, "Notification Service", "Shared Service", "Generates approval, alert, and workflow notifications")
+  Container(policyrepo, "Policy Repository", "Docs / Controlled Content", "Maintains policies, procedures, standards, and records under document control")
+}
+
+Rel(owner, inventory, "Uses")
+Rel(owner, social, "Uses")
+Rel(owner, wpmanage, "Uses")
+Rel(owner, mrp, "Uses")
+Rel(owner, finance, "Uses")
+Rel(owner, policyrepo, "Governs")
+
+Rel(staff, inventory, "Uses")
+Rel(staff, social, "Uses")
+Rel(staff, wpmanage, "Uses")
+Rel(staff, mrp, "Uses")
+Rel(staff, policyrepo, "Reads")
+
+Rel(inventory, txdb, "Reads from and writes to")
+Rel(social, txdb, "Reads from and writes to")
+Rel(wpmanage, txdb, "Reads from and writes to")
+Rel(mrp, txdb, "Reads from and writes to")
+Rel(finance, txdb, "Reads from and writes to")
+
+Rel(inventory, auth, "Authenticates through")
+Rel(social, auth, "Authenticates through")
+Rel(wpmanage, auth, "Authenticates through")
+Rel(mrp, auth, "Authenticates through")
+Rel(finance, auth, "Authenticates through")
+
+Rel(inventory, datarepo, "Uses shared data from")
+Rel(social, datarepo, "Uses shared data from")
+Rel(wpmanage, datarepo, "Uses shared data from")
+Rel(mrp, datarepo, "Uses shared data from")
+Rel(finance, datarepo, "Uses shared data from")
+
+Rel(inventory, api, "Sends and receives integration events through")
+Rel(social, api, "Sends and receives integration events through")
+Rel(wpmanage, api, "Sends and receives integration events through")
+Rel(mrp, api, "Sends and receives integration events through")
+Rel(finance, api, "Sends and receives integration events through")
+
+Rel(api, wordpress, "Publishes and synchronizes with")
+Rel(api, n8n, "Triggers and receives workflows from")
+Rel(api, mail, "Sends messages through")
+Rel(api, facebook, "Publishes content to")
+Rel(api, instagram, "Publishes content to")
+Rel(api, xsocial, "Publishes content to")
+
+Rel(policyrepo, git, "Stores version-controlled policy source in")
+Rel(policyrepo, notify, "Uses for review and approval reminders")
+
+@enduml
\ No newline at end of file
diff --git a/docs/architecture/containers/platform-containers.md b/docs/architecture/containers/platform-containers.md
index 29c5cf4..9cc454f 100644
--- a/docs/architecture/containers/platform-containers.md
+++ b/docs/architecture/containers/platform-containers.md
@@ -1,3 +1,44 @@
 # Platform Containers
 
-This page describes the major applications and shared platform services.
+This diagram shows the major application and shared-service containers that make up the Kell Creations Platform.
+
+## Purpose
+
+This view breaks the platform into its primary internal applications, shared services, and controlled content repositories. It is intended to show how the platform is logically organized before moving deeper into component-level and deployment-level views.
+
+## Diagram Source
+
+The source for this diagram is maintained as architecture code in:
+
+`architecture/workspace/containers-platform.puml`
+
+## Included Application Containers
+
+- Inventory Application
+- Social Media Management
+- WordPress Management
+- Craft Manufacturing / MRP
+- Financial Analysis
+
+## Included Shared Platform Containers
+
+- Transaction Database
+- Authentication Service
+- Shared Data Repository
+- API Orchestrator
+- Notification Service
+- Policy Repository
+
+## Connected External Systems
+
+- WordPress
+- n8n
+- Mail Server
+- Forgejo Git
+- Facebook
+- Instagram
+- X
+
+## Notes
+
+This container view will later be expanded with component diagrams for each major application and service area. It also establishes the architectural basis for documenting shared authentication, shared data, workflow orchestration, and controlled policy management across the entire Kell Creations platform.
\ No newline at end of file