diff --git a/content/docs/developers/meta.json b/content/docs/developers/meta.json
index f02157e32..4733e095a 100644
--- a/content/docs/developers/meta.json
+++ b/content/docs/developers/meta.json
@@ -4,6 +4,7 @@
   "pages": [
     "micro-kernel",
     "writing-plugins",
+    "plugin-ecosystem",
     "custom-widgets",
     "server-drivers",
     "cli-tools"
diff --git a/content/docs/developers/plugin-ecosystem.mdx b/content/docs/developers/plugin-ecosystem.mdx
new file mode 100644
index 000000000..b51ff3616
--- /dev/null
+++ b/content/docs/developers/plugin-ecosystem.mdx
@@ -0,0 +1,776 @@
+---
+title: Plugin Ecosystem Architecture
+description: Building an interoperable plugin ecosystem for ObjectStack with vendor-agnostic protocols
+---
+
+# Plugin Ecosystem Architecture
+
+## Overview
+
+ObjectStack uses a MicroKernel Architecture where all functionality is implemented through plugins. This document defines a comprehensive plugin ecosystem specification that ensures plugins from different vendors can call each other, collaborate, and compose together.
+
+---
+
+## 🎯 Design Goals
+
+### 1. **Protocol-First**
+
+Plugins declare capabilities through implementing **Protocols** rather than hard-coded dependencies, similar to:
+- Kubernetes CRDs (Custom Resource Definitions)
+- OSGi Service Registry
+- Eclipse Extension Points
+
+### 2. **Semantic Versioning**
+
+All protocols and plugins must use Semantic Versioning (SemVer) for compatibility management:
+- Major: Breaking changes
+- Minor: Backwards-compatible feature additions
+- Patch: Backwards-compatible bug fixes
+
+### 3. **Reverse Domain Naming**
+
+All plugins and protocols use reverse domain notation to ensure global uniqueness:
+```
+{domain}.{category}.{name}
+```
+
+**Examples:**
+- Plugin: `com.acme.crm.customer-management`
+- Protocol: `com.objectstack.protocol.storage.v1`
+- Interface: `com.acme.crm.interface.contact_service`
+
+### 4. **Loose Coupling**
+
+Plugins communicate through **Interfaces** and **Extension Points**, not direct implementation dependencies.
+
+---
+
+## 🏗️ Core Components
+
+### 1. Protocol Declaration
+
+A **Protocol** defines a standardized set of capabilities. Plugins declare which protocols they implement.
+
+```typescript
+import { PluginCapabilityManifest } from '@objectstack/spec/system';
+
+const capabilities: PluginCapabilityManifest = {
+  implements: [
+    {
+      protocol: {
+        id: 'com.objectstack.protocol.storage.v1',
+        label: 'Storage Protocol v1',
+        version: { major: 1, minor: 0, patch: 0 },
+      },
+      conformance: 'full',  // full | partial | experimental | deprecated
+      certified: true,
+    },
+  ],
+};
+```
+
+#### Conformance Levels
+
+| Level | Description |
+|-------|-------------|
+| `full` | Complete implementation of all protocol features |
+| `partial` | Subset implementation with specific features listed |
+| `experimental` | Unstable/preview implementation |
+| `deprecated` | Still supported but scheduled for removal |
+
+### 2. Interface Provision
+
+An **Interface** defines the service contract a plugin provides. Other plugins can call these interfaces.
+
+```typescript
+const capabilities: PluginCapabilityManifest = {
+  provides: [
+    {
+      id: 'com.acme.crm.interface.contact_service',
+      name: 'ContactService',
+      version: { major: 1, minor: 0, patch: 0 },
+      stability: 'stable',  // stable | beta | alpha | experimental
+      
+      methods: [
+        {
+          name: 'getContact',
+          description: 'Retrieve a contact by ID',
+          parameters: [
+            { name: 'id', type: 'string', required: true },
+          ],
+          returnType: 'Contact',
+          async: true,
+        },
+        {
+          name: 'createContact',
+          parameters: [
+            { name: 'data', type: 'ContactInput', required: true },
+          ],
+          returnType: 'Contact',
+          async: true,
+        },
+      ],
+      
+      events: [
+        {
+          name: 'contactCreated',
+          description: 'Fired when a new contact is created',
+          payload: 'Contact',
+        },
+      ],
+    },
+  ],
+};
+```
+
+### 3. Dependency Declaration
+
+Plugins declare dependencies on other plugins and specify required capabilities.
+
+```typescript
+const capabilities: PluginCapabilityManifest = {
+  requires: [
+    {
+      pluginId: 'com.objectstack.driver.postgres',
+      version: '^1.0.0',
+      optional: false,
+      requiredCapabilities: [
+        'com.objectstack.protocol.storage.v1',
+        'com.objectstack.protocol.transactions.v1',
+      ],
+    },
+    {
+      pluginId: 'com.acme.analytics',
+      version: '>=2.0.0',
+      optional: true,
+      reason: 'Enhanced analytics features',
+    },
+  ],
+};
+```
+
+### 4. Extension Points
+
+**Extension Points** allow plugins to declare where other plugins can extend functionality.
+
+```typescript
+const capabilities: PluginCapabilityManifest = {
+  extensionPoints: [
+    {
+      id: 'com.acme.crm.extension.contact_validator',
+      name: 'Contact Validator',
+      type: 'validator',  // action | hook | widget | provider | transformer | validator | decorator
+      cardinality: 'multiple',  // single | multiple
+      contract: {
+        input: 'Contact',
+        output: 'ValidationResult',
+      },
+    },
+  ],
+  
+  extensions: [
+    {
+      targetPluginId: 'com.acme.crm',
+      extensionPointId: 'com.acme.crm.extension.contact_validator',
+      implementation: './validators/email-validator.ts',
+      priority: 50,
+    },
+  ],
+};
+```
+
+#### Extension Point Types
+
+| Type | Purpose |
+|------|---------|
+| `action` | Executable actions |
+| `hook` | Lifecycle event hooks |
+| `widget` | UI components |
+| `provider` | Data/service providers |
+| `transformer` | Data transformers |
+| `validator` | Data validators |
+| `decorator` | Functionality decorators |
+
+---
+
+## 📝 Naming Conventions
+
+### Overview
+
+ObjectStack uses different naming conventions to distinguish between **package-level identifiers** (for distribution and installation) and **code-level identifiers** (for services and data access).
+
+### 1. Plugin Identifiers
+
+**Format:**
+```
+{vendor-domain}.{category}.{plugin-name}
+```
+
+**Rules:**
+- Use reverse domain notation
+- All lowercase
+- Use hyphens for word separation (NPM package naming convention)
+- Avoid underscores and camelCase
+
+**Examples:**
+```
+✅ com.objectstack.driver.postgres
+✅ com.acme.crm.customer-management
+✅ org.apache.kafka.connector
+❌ com.acme.CRM  (Do not use uppercase)
+❌ com.acme.crm_plugin  (Do not use underscores)
+```
+
+### 2. Protocol Identifiers
+
+**Format:**
+```
+{vendor-domain}.protocol.{category}.{name}.v{major}
+```
+
+**Examples:**
+```
+com.objectstack.protocol.storage.v1
+com.objectstack.protocol.auth.oauth2.v2
+com.acme.protocol.payment.stripe.v1
+```
+
+### 3. Interface Identifiers
+
+**Format:**
+```
+{plugin-id}.interface.{interface-name}
+```
+
+**Rules:**
+- Use snake_case for interface names (consistent with service names in code)
+- Follow ObjectStack data layer naming convention
+
+**Examples:**
+```
+✅ com.acme.crm.interface.contact_service
+✅ com.acme.analytics.interface.metrics_collector
+✅ com.acme.auth.interface.user_provider
+```
+
+### 4. Extension Point Identifiers
+
+**Format:**
+```
+{plugin-id}.extension.{extension-name}
+```
+
+**Rules:**
+- Use snake_case for extension names (consistent with method/function naming)
+
+**Examples:**
+```
+✅ com.acme.crm.extension.contact_validator
+✅ com.acme.app.extension.theme_provider
+✅ com.acme.crm.extension.customer_enrichment
+```
+
+### Naming Convention Summary
+
+| Type | Format | Separator | Example |
+|------|--------|-----------|---------|
+| Plugin ID | `{domain}.{category}.{name}` | kebab-case (hyphens) | `com.acme.crm.customer-management` |
+| Protocol ID | `{domain}.protocol.{name}.v{N}` | kebab-case | `com.objectstack.protocol.storage.v1` |
+| Interface ID | `{plugin}.interface.{name}` | snake_case | `com.acme.crm.interface.contact_service` |
+| Extension ID | `{plugin}.extension.{name}` | snake_case | `com.acme.crm.extension.contact_validator` |
+
+**Important Notes:**
+- **Package-level identifiers** (plugins, protocols) use kebab-case, following NPM package naming convention
+- **Code-level identifiers** (interfaces, extensions) use snake_case, consistent with ObjectStack data layer naming
+
+---
+
+## 🔄 Plugin Discovery & Registry
+
+### Plugin Registry
+
+The ObjectStack Hub provides a centralized plugin registry that supports:
+- Plugin publishing and version management
+- Dependency resolution
+- Capability searching
+- Quality scoring
+- Security scanning
+
+```typescript
+import { PluginRegistryEntry } from '@objectstack/spec/hub';
+
+const registryEntry: PluginRegistryEntry = {
+  id: 'com.acme.crm.customer-management',
+  version: '1.2.3',
+  name: 'Customer Management Plugin',
+  description: 'Comprehensive customer relationship management',
+  
+  category: 'data',
+  tags: ['crm', 'customer', 'sales'],
+  
+  vendor: {
+    id: 'com.acme',
+    name: 'ACME Corporation',
+    verified: true,
+    trustLevel: 'verified',
+  },
+  
+  capabilities: { /* ... */ },
+  
+  quality: {
+    testCoverage: 85,
+    documentationScore: 90,
+    securityScan: {
+      passed: true,
+      vulnerabilities: { critical: 0, high: 0, medium: 0, low: 0 },
+    },
+  },
+  
+  statistics: {
+    downloads: 15000,
+    ratings: { average: 4.5, count: 120 },
+  },
+};
+```
+
+### Search & Filtering
+
+```typescript
+import { PluginSearchFilters } from '@objectstack/spec/hub';
+
+const filters: PluginSearchFilters = {
+  query: 'CRM',
+  category: ['data', 'integration'],
+  implementsProtocols: ['com.objectstack.protocol.storage.v1'],
+  trustLevel: ['official', 'verified'],
+  minRating: 4.0,
+  sortBy: 'downloads',
+};
+```
+
+---
+
+## 🔐 Plugin Security & Quality
+
+### 1. Vendor Verification
+
+The plugin registry supports multiple trust levels:
+
+| Trust Level | Description |
+|-------------|-------------|
+| `official` | Official ObjectStack plugins |
+| `verified` | Verified vendors |
+| `community` | Community contributions |
+| `unverified` | Unverified vendors |
+
+### 2. Quality Metrics
+
+```typescript
+quality: {
+  testCoverage: 85,
+  documentationScore: 90,
+  codeQuality: 88,
+  
+  securityScan: {
+    lastScanDate: '2024-01-15T00:00:00Z',
+    vulnerabilities: {
+      critical: 0,
+      high: 0,
+      medium: 1,
+      low: 3,
+    },
+    passed: true,
+  },
+  
+  conformanceTests: [
+    {
+      protocolId: 'com.objectstack.protocol.storage.v1',
+      passed: true,
+      totalTests: 150,
+      passedTests: 150,
+    },
+  ],
+}
+```
+
+### 3. Permission Declaration
+
+Plugins must declare required permissions in their manifest:
+
+```typescript
+// objectstack.config.ts
+export default {
+  id: 'com.acme.analytics',
+  permissions: [
+    'system.user.read',
+    'system.data.write',
+    'network.http.request',
+    'storage.local.write',
+  ],
+};
+```
+
+---
+
+## 🌐 Inter-Plugin Communication Patterns
+
+### Pattern 1: Interface Invocation
+
+Plugin A invokes services provided by Plugin B.
+
+```typescript
+// Plugin B: Provides Interface
+export class ContactServicePlugin implements Plugin {
+  name = 'com.acme.crm';
+  
+  async init(ctx: PluginContext) {
+    ctx.registerService('contact-service', {
+      async getContact(id: string): Promise<Contact> {
+        // Implementation
+      },
+    });
+  }
+}
+
+// Plugin A: Uses Interface
+export class ReportingPlugin implements Plugin {
+  name = 'com.acme.reporting';
+  dependencies = ['com.acme.crm'];
+  
+  async start(ctx: PluginContext) {
+    const contactService = ctx.getService('contact-service');
+    const contact = await contactService.getContact('123');
+  }
+}
+```
+
+### Pattern 2: Event Bus
+
+Plugins communicate through publish/subscribe pattern.
+
+```typescript
+// Plugin A: Publishes Events
+await ctx.trigger('crm:contact:created', {
+  contactId: '123',
+  data: contact,
+});
+
+// Plugin B: Subscribes to Events
+ctx.hook('crm:contact:created', async (event) => {
+  console.log('New contact:', event.data);
+});
+```
+
+### Pattern 3: Extension Contribution
+
+Plugin A contributes extensions to Plugin B.
+
+```typescript
+// Plugin B: Defines Extension Point
+capabilities: {
+  extensionPoints: [{
+    id: 'com.acme.crm.extension.contact_validator',
+    type: 'validator',
+    contract: {
+      input: 'Contact',
+      output: 'ValidationResult',
+    },
+  }],
+}
+
+// Plugin A: Contributes Extension
+capabilities: {
+  extensions: [{
+    targetPluginId: 'com.acme.crm',
+    extensionPointId: 'com.acme.crm.extension.contact_validator',
+    implementation: './validators/email-validator.ts',
+  }],
+}
+```
+
+---
+
+## 📦 Complete Example
+
+### Scenario: Building a CRM Ecosystem
+
+#### 1. Core CRM Plugin
+
+```typescript
+// objectstack.config.ts
+import { ObjectStackManifest } from '@objectstack/spec/system';
+
+const manifest: ObjectStackManifest = {
+  id: 'com.acme.crm',
+  version: '1.0.0',
+  type: 'plugin',
+  name: 'ACME CRM Core',
+  
+  capabilities: {
+    implements: [
+      {
+        protocol: {
+          id: 'com.objectstack.protocol.storage.v1',
+          label: 'Storage Protocol',
+          version: { major: 1, minor: 0, patch: 0 },
+        },
+        conformance: 'full',
+      },
+    ],
+    
+    provides: [
+      {
+        id: 'com.acme.crm.interface.customer_service',
+        name: 'CustomerService',
+        version: { major: 1, minor: 0, patch: 0 },
+        methods: [
+          {
+            name: 'getCustomer',
+            parameters: [{ name: 'id', type: 'string' }],
+            returnType: 'Customer',
+            async: true,
+          },
+        ],
+      },
+    ],
+    
+    extensionPoints: [
+      {
+        id: 'com.acme.crm.extension.customer_enrichment',
+        name: 'Customer Data Enrichment',
+        type: 'transformer',
+        cardinality: 'multiple',
+      },
+    ],
+  },
+  
+  objects: ['./src/objects/*.object.ts'],
+};
+
+export default manifest;
+```
+
+#### 2. Email Integration Plugin
+
+```typescript
+// objectstack.config.ts
+const manifest: ObjectStackManifest = {
+  id: 'com.acme.crm.email-integration',
+  version: '1.0.0',
+  type: 'plugin',
+  name: 'Email Integration for CRM',
+  
+  capabilities: {
+    requires: [
+      {
+        pluginId: 'com.acme.crm',
+        version: '^1.0.0',
+        requiredCapabilities: [
+          'com.acme.crm.interface.customer_service',
+        ],
+      },
+    ],
+    
+    implements: [
+      {
+        protocol: {
+          id: 'com.objectstack.protocol.email.v1',
+          label: 'Email Protocol',
+          version: { major: 1, minor: 0, patch: 0 },
+        },
+        conformance: 'full',
+      },
+    ],
+    
+    extensions: [
+      {
+        targetPluginId: 'com.acme.crm',
+        extensionPointId: 'com.acme.crm.extension.customer_enrichment',
+        implementation: './enrichment/email-enricher.ts',
+        priority: 100,
+      },
+    ],
+  },
+};
+
+export default manifest;
+```
+
+#### 3. Analytics Plugin
+
+```typescript
+const manifest: ObjectStackManifest = {
+  id: 'com.acme.crm.analytics',
+  version: '2.0.0',
+  type: 'plugin',
+  name: 'CRM Analytics',
+  
+  capabilities: {
+    requires: [
+      {
+        pluginId: 'com.acme.crm',
+        version: '^1.0.0',
+      },
+    ],
+    
+    provides: [
+      {
+        id: 'com.acme.crm.interface.analytics_service',
+        name: 'AnalyticsService',
+        version: { major: 2, minor: 0, patch: 0 },
+        methods: [
+          {
+            name: 'getMetrics',
+            parameters: [
+              { name: 'query', type: 'MetricsQuery' },
+            ],
+            returnType: 'MetricsResult',
+            async: true,
+          },
+        ],
+        events: [
+          {
+            name: 'metricsUpdated',
+            payload: 'MetricsSnapshot',
+          },
+        ],
+      },
+    ],
+  },
+};
+
+export default manifest;
+```
+
+---
+
+## 🚀 Best Practices
+
+### 1. Protocol Design
+
+#### ✅ Recommended
+
+- Use semantic versioning
+- Protocols should be stable and backwards compatible
+- Provide clear protocol documentation and examples
+- Define explicit test specifications
+
+#### ❌ Avoid
+
+- Exposing implementation details in protocols
+- Frequent breaking changes
+- Undocumented protocols
+
+### 2. Plugin Design
+
+#### ✅ Recommended
+```typescript
+// Explicitly declare dependencies
+requires: [{
+  pluginId: 'com.objectstack.driver.postgres',
+  version: '^1.0.0',
+  requiredCapabilities: ['com.objectstack.protocol.storage.v1'],
+}]
+
+// Use extension points instead of hard-coding
+extensionPoints: [{
+  id: 'com.acme.app.extension.authentication',
+  type: 'provider',
+  cardinality: 'single',
+}]
+
+// Provide clear interfaces
+provides: [{
+  id: 'com.acme.interface.user_service',
+  methods: [/* well-documented methods */],
+  stability: 'stable',
+}]
+```
+
+#### ❌ Avoid
+```typescript
+// ❌ Don't directly import other plugins
+import { UserService } from '@acme/other-plugin';
+
+// ❌ Don't use global state
+global.myPluginData = {};
+
+// ❌ Don't hard-code plugin identifiers
+const otherId = 'other-plugin';  // Should use id from manifest
+```
+
+### 3. Version Management
+
+```typescript
+// ✅ Use SemVer ranges
+version: '^1.0.0'    // >= 1.0.0 < 2.0.0
+version: '~1.2.3'    // >= 1.2.3 < 1.3.0
+version: '>=2.0.0 <3.0.0'
+
+// ✅ Mark deprecations
+deprecated: true,
+deprecationMessage: 'Use com.acme.crm.v2 instead',
+replacedBy: 'com.acme.crm.v2',
+```
+
+### 4. Testing & Validation
+
+```typescript
+// Protocol Conformance Tests
+describe('Storage Protocol Conformance', () => {
+  it('should implement all required methods', async () => {
+    const driver = new MyDriver();
+    expect(driver.query).toBeDefined();
+    expect(driver.insert).toBeDefined();
+    // ...
+  });
+});
+
+// Integration Tests
+describe('Plugin Integration', () => {
+  it('should work with CRM plugin', async () => {
+    const kernel = new ObjectKernel();
+    kernel.use(new CRMPlugin());
+    kernel.use(new MyPlugin());
+    await kernel.bootstrap();
+    // Test inter-plugin communication
+  });
+});
+```
+
+---
+
+## 📚 References
+
+### Related Documentation
+- [MicroKernel Architecture](/docs/developers/micro-kernel)
+- [Writing Plugins](/docs/developers/writing-plugins)
+- [Manifest Schema](/docs/references/system/manifest)
+- [Plugin Capability Protocol](/docs/references/system/plugin-capability)
+- [Plugin Registry](/docs/references/hub/plugin-registry)
+
+### Industry Standard References
+- [OSGi Service Platform](https://www.osgi.org/)
+- [Eclipse Extension Points](https://wiki.eclipse.org/FAQ_What_are_extensions_and_extension_points)
+- [Kubernetes CRDs](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/)
+- [VS Code Extension API](https://code.visualstudio.com/api)
+
+---
+
+## 🎓 Summary
+
+The ObjectStack plugin ecosystem ensures vendor interoperability through:
+
+1. **Protocol-First Design** - Plugins communicate through protocols not implementations
+2. **Reverse Domain Naming** - Ensures globally unique identifiers
+3. **Capability Declaration** - Explicit interface and dependency declarations
+4. **Extension Points** - Standardized extension mechanisms
+5. **Version Management** - Semantic versioning
+6. **Quality Assurance** - Testing, certification, and scoring systems
+7. **Centralized Registry** - Plugin discovery and dependency resolution
+
+By following these specifications, plugins from different vendors can:
+- 🔍 Discover and depend on each other
+- 🤝 Safely invoke each other's services
+- 🔌 Flexibly compose and extend
+- 📈 Continuously evolve without breaking compatibility
diff --git a/content/docs/references/hub/index.mdx b/content/docs/references/hub/index.mdx
index a2bcf34f2..9821de8e4 100644
--- a/content/docs/references/hub/index.mdx
+++ b/content/docs/references/hub/index.mdx
@@ -11,6 +11,7 @@ This section contains all protocol schemas for the hub layer of ObjectStack.
   <Card href="./composer" title="Composer" description="Source: packages/spec/src/hub/composer.zod.ts" />
   <Card href="./license" title="License" description="Source: packages/spec/src/hub/license.zod.ts" />
   <Card href="./marketplace" title="Marketplace" description="Source: packages/spec/src/hub/marketplace.zod.ts" />
+  <Card href="./plugin-registry" title="Plugin Registry" description="Source: packages/spec/src/hub/plugin-registry.zod.ts" />
   <Card href="./space" title="Space" description="Source: packages/spec/src/hub/space.zod.ts" />
   <Card href="./tenant" title="Tenant" description="Source: packages/spec/src/hub/tenant.zod.ts" />
 </Cards>
diff --git a/content/docs/references/hub/meta.json b/content/docs/references/hub/meta.json
index e3a0b24fb..316797192 100644
--- a/content/docs/references/hub/meta.json
+++ b/content/docs/references/hub/meta.json
@@ -4,6 +4,7 @@
     "composer",
     "license",
     "marketplace",
+    "plugin-registry",
     "space",
     "tenant"
   ]
diff --git a/content/docs/references/hub/plugin-registry.mdx b/content/docs/references/hub/plugin-registry.mdx
new file mode 100644
index 000000000..23cf14461
--- /dev/null
+++ b/content/docs/references/hub/plugin-registry.mdx
@@ -0,0 +1,130 @@
+---
+title: Plugin Registry
+description: Plugin Registry protocol schemas
+---
+
+# Plugin Registry
+
+<Callout type="info">
+**Source:** `packages/spec/src/hub/plugin-registry.zod.ts`
+</Callout>
+
+## TypeScript Usage
+
+```typescript
+import { PluginInstallConfigSchema, PluginQualityMetricsSchema, PluginRegistryEntrySchema, PluginSearchFiltersSchema, PluginStatisticsSchema, PluginVendorSchema } from '@objectstack/spec/hub';
+import type { PluginInstallConfig, PluginQualityMetrics, PluginRegistryEntry, PluginSearchFilters, PluginStatistics, PluginVendor } from '@objectstack/spec/hub';
+
+// Validate data
+const result = PluginInstallConfigSchema.parse(data);
+```
+
+---
+
+## PluginInstallConfig
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **pluginId** | `string` | ✅ |  |
+| **version** | `string` | optional | Defaults to latest |
+| **config** | `Record<string, any>` | optional |  |
+| **autoUpdate** | `boolean` | optional |  |
+| **options** | `object` | optional |  |
+
+---
+
+## PluginQualityMetrics
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **testCoverage** | `number` | optional |  |
+| **documentationScore** | `number` | optional |  |
+| **codeQuality** | `number` | optional |  |
+| **securityScan** | `object` | optional |  |
+| **conformanceTests** | `object[]` | optional |  |
+
+---
+
+## PluginRegistryEntry
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **id** | `string` | ✅ | Plugin identifier (reverse domain notation) |
+| **version** | `string` | ✅ |  |
+| **name** | `string` | ✅ |  |
+| **description** | `string` | optional |  |
+| **readme** | `string` | optional |  |
+| **category** | `Enum<'data' \| 'integration' \| 'ui' \| 'analytics' \| 'security' \| 'automation' \| 'ai' \| 'utility' \| 'driver' \| 'gateway' \| 'adapter'>` | optional |  |
+| **tags** | `string[]` | optional |  |
+| **vendor** | `object` | ✅ |  |
+| **capabilities** | `object` | optional |  |
+| **compatibility** | `object` | optional |  |
+| **links** | `object` | optional |  |
+| **media** | `object` | optional |  |
+| **quality** | `object` | optional |  |
+| **statistics** | `object` | optional |  |
+| **license** | `string` | optional | SPDX license identifier |
+| **pricing** | `object` | optional |  |
+| **publishedAt** | `string` | optional |  |
+| **updatedAt** | `string` | optional |  |
+| **deprecated** | `boolean` | optional |  |
+| **deprecationMessage** | `string` | optional |  |
+| **replacedBy** | `string` | optional | Plugin ID that replaces this one |
+| **flags** | `object` | optional |  |
+
+---
+
+## PluginSearchFilters
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **query** | `string` | optional |  |
+| **category** | `string[]` | optional |  |
+| **tags** | `string[]` | optional |  |
+| **trustLevel** | `Enum<'official' \| 'verified' \| 'community' \| 'unverified'>[]` | optional |  |
+| **implementsProtocols** | `string[]` | optional |  |
+| **pricingModel** | `Enum<'free' \| 'freemium' \| 'paid' \| 'enterprise'>[]` | optional |  |
+| **minRating** | `number` | optional |  |
+| **sortBy** | `Enum<'relevance' \| 'downloads' \| 'rating' \| 'updated' \| 'name'>` | optional |  |
+| **sortOrder** | `Enum<'asc' \| 'desc'>` | optional |  |
+| **page** | `integer` | optional |  |
+| **limit** | `integer` | optional |  |
+
+---
+
+## PluginStatistics
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **downloads** | `integer` | optional |  |
+| **downloadsLastMonth** | `integer` | optional |  |
+| **activeInstallations** | `integer` | optional |  |
+| **ratings** | `object` | optional |  |
+| **stars** | `integer` | optional |  |
+| **dependents** | `integer` | optional |  |
+
+---
+
+## PluginVendor
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **id** | `string` | ✅ | Vendor identifier (reverse domain) |
+| **name** | `string` | ✅ |  |
+| **website** | `string` | optional |  |
+| **email** | `string` | optional |  |
+| **verified** | `boolean` | optional | Whether vendor is verified by ObjectStack |
+| **trustLevel** | `Enum<'official' \| 'verified' \| 'community' \| 'unverified'>` | optional |  |
+
diff --git a/content/docs/references/system/index.mdx b/content/docs/references/system/index.mdx
index dd4607dd2..4883942a9 100644
--- a/content/docs/references/system/index.mdx
+++ b/content/docs/references/system/index.mdx
@@ -19,6 +19,7 @@ This section contains all protocol schemas for the system layer of ObjectStack.
   <Card href="./logger" title="Logger" description="Source: packages/spec/src/system/logger.zod.ts" />
   <Card href="./manifest" title="Manifest" description="Source: packages/spec/src/system/manifest.zod.ts" />
   <Card href="./plugin" title="Plugin" description="Source: packages/spec/src/system/plugin.zod.ts" />
+  <Card href="./plugin-capability" title="Plugin Capability" description="Source: packages/spec/src/system/plugin-capability.zod.ts" />
   <Card href="./scoped-storage" title="Scoped Storage" description="Source: packages/spec/src/system/scoped-storage.zod.ts" />
   <Card href="./translation" title="Translation" description="Source: packages/spec/src/system/translation.zod.ts" />
 </Cards>
diff --git a/content/docs/references/system/manifest.mdx b/content/docs/references/system/manifest.mdx
index a13db0918..cf6fbb749 100644
--- a/content/docs/references/system/manifest.mdx
+++ b/content/docs/references/system/manifest.mdx
@@ -39,5 +39,6 @@ const result = ManifestSchema.parse(data);
 | **configuration** | `object` | optional | Plugin configuration settings |
 | **contributes** | `object` | optional | Platform contributions |
 | **data** | `object[]` | optional | Initial seed data |
+| **capabilities** | `object` | optional | Plugin capability declarations for interoperability |
 | **extensions** | `Record<string, any>` | optional | Extension points and contributions |
 
diff --git a/content/docs/references/system/meta.json b/content/docs/references/system/meta.json
index 09e989f8b..491685715 100644
--- a/content/docs/references/system/meta.json
+++ b/content/docs/references/system/meta.json
@@ -12,6 +12,7 @@
     "logger",
     "manifest",
     "plugin",
+    "plugin-capability",
     "scoped-storage",
     "translation"
   ]
diff --git a/content/docs/references/system/plugin-capability.mdx b/content/docs/references/system/plugin-capability.mdx
new file mode 100644
index 000000000..83324fd7a
--- /dev/null
+++ b/content/docs/references/system/plugin-capability.mdx
@@ -0,0 +1,151 @@
+---
+title: Plugin Capability
+description: Plugin Capability protocol schemas
+---
+
+# Plugin Capability
+
+<Callout type="info">
+**Source:** `packages/spec/src/system/plugin-capability.zod.ts`
+</Callout>
+
+## TypeScript Usage
+
+```typescript
+import { CapabilityConformanceLevelSchema, ExtensionPointSchema, PluginCapabilitySchema, PluginCapabilityManifestSchema, PluginDependencySchema, PluginInterfaceSchema, ProtocolFeatureSchema, ProtocolReferenceSchema, ProtocolVersionSchema } from '@objectstack/spec/system';
+import type { CapabilityConformanceLevel, ExtensionPoint, PluginCapability, PluginCapabilityManifest, PluginDependency, PluginInterface, ProtocolFeature, ProtocolReference, ProtocolVersion } from '@objectstack/spec/system';
+
+// Validate data
+const result = CapabilityConformanceLevelSchema.parse(data);
+```
+
+---
+
+## CapabilityConformanceLevel
+
+Level of protocol conformance
+
+### Allowed Values
+
+* `full`
+* `partial`
+* `experimental`
+* `deprecated`
+
+---
+
+## ExtensionPoint
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **id** | `string` | ✅ | Unique extension point identifier |
+| **name** | `string` | ✅ |  |
+| **description** | `string` | optional |  |
+| **type** | `Enum<'action' \| 'hook' \| 'widget' \| 'provider' \| 'transformer' \| 'validator' \| 'decorator'>` | ✅ |  |
+| **contract** | `object` | optional |  |
+| **cardinality** | `Enum<'single' \| 'multiple'>` | optional | Whether multiple extensions can register to this point |
+
+---
+
+## PluginCapability
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **protocol** | `object` | ✅ |  |
+| **conformance** | `Enum<'full' \| 'partial' \| 'experimental' \| 'deprecated'>` | optional | Level of protocol conformance |
+| **implementedFeatures** | `string[]` | optional | List of implemented feature names |
+| **features** | `object[]` | optional |  |
+| **metadata** | `Record<string, any>` | optional |  |
+| **certified** | `boolean` | optional | Has passed official conformance tests |
+| **certificationDate** | `string` | optional |  |
+
+---
+
+## PluginCapabilityManifest
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **implements** | `object[]` | optional | List of protocols this plugin conforms to |
+| **provides** | `object[]` | optional | Services/APIs this plugin offers to others |
+| **requires** | `object[]` | optional | Required plugins and their capabilities |
+| **extensionPoints** | `object[]` | optional | Points where other plugins can extend this plugin |
+| **extensions** | `object[]` | optional | Extensions contributed to other plugins |
+
+---
+
+## PluginDependency
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **pluginId** | `string` | ✅ | Required plugin identifier |
+| **version** | `string` | ✅ | Semantic version constraint |
+| **optional** | `boolean` | optional |  |
+| **reason** | `string` | optional |  |
+| **requiredCapabilities** | `string[]` | optional | Protocol IDs the dependency must support |
+
+---
+
+## PluginInterface
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **id** | `string` | ✅ | Unique interface identifier |
+| **name** | `string` | ✅ |  |
+| **description** | `string` | optional |  |
+| **version** | `object` | ✅ | Semantic version of the protocol |
+| **methods** | `object[]` | ✅ |  |
+| **events** | `object[]` | optional |  |
+| **stability** | `Enum<'stable' \| 'beta' \| 'alpha' \| 'experimental'>` | optional |  |
+
+---
+
+## ProtocolFeature
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **name** | `string` | ✅ | Feature identifier within the protocol |
+| **enabled** | `boolean` | optional |  |
+| **description** | `string` | optional |  |
+| **sinceVersion** | `string` | optional | Version when this feature was added |
+| **deprecatedSince** | `string` | optional | Version when deprecated |
+
+---
+
+## ProtocolReference
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **id** | `string` | ✅ | Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1) |
+| **label** | `string` | ✅ |  |
+| **version** | `object` | ✅ | Semantic version of the protocol |
+| **specification** | `string` | optional | URL or path to protocol specification |
+| **description** | `string` | optional |  |
+
+---
+
+## ProtocolVersion
+
+Semantic version of the protocol
+
+### Properties
+
+| Property | Type | Required | Description |
+| :--- | :--- | :--- | :--- |
+| **major** | `integer` | ✅ |  |
+| **minor** | `integer` | ✅ |  |
+| **patch** | `integer` | ✅ |  |
+
diff --git a/examples/plugin-advanced-crm/README.md b/examples/plugin-advanced-crm/README.md
new file mode 100644
index 000000000..8cb727724
--- /dev/null
+++ b/examples/plugin-advanced-crm/README.md
@@ -0,0 +1,174 @@
+# Advanced CRM Plugin Example
+
+This example demonstrates a comprehensive ObjectStack plugin that showcases the full capability manifest system.
+
+## Key Features Demonstrated
+
+### 1. Protocol Implementation
+- Implements `com.objectstack.protocol.storage.v1` with full conformance
+- Partially implements `com.objectstack.protocol.sync.v1` with specific features
+
+### 2. Service Interfaces
+Provides two stable interfaces:
+- `CustomerService` - Customer data management (CRUD operations)
+- `OpportunityService` - Sales opportunity tracking
+
+### 3. Plugin Dependencies
+Declares dependencies on:
+- `com.objectstack.driver.postgres` (required) - Data storage
+- `com.objectstack.auth.oauth2` (required) - Authentication
+- `com.acme.analytics.basic` (optional) - Enhanced analytics
+
+### 4. Extension Points
+Defines four extension points:
+- `customer_enrichment` - Transform customer data
+- `customer_validator` - Validate customer data
+- `opportunity_scoring` - Calculate win probability
+- `dashboard_widget` - Custom UI widgets
+
+### 5. Extensions Contributed
+- Contributes a customer summary widget to the dashboard
+
+## Naming Conventions
+
+This example follows ObjectStack naming standards:
+
+- **Plugin ID**: `com.acme.crm.advanced` (reverse domain notation)
+- **Protocol IDs**: `com.objectstack.protocol.{name}.v{major}`
+- **Interface IDs**: `com.acme.crm.interface.{name}`
+- **Extension Point IDs**: `com.acme.crm.extension.{name}`
+
+## Interoperability
+
+This plugin is designed to work with other plugins in the ecosystem:
+
+```
+┌─────────────────────────────────┐
+│  com.acme.crm.advanced          │
+│  (This Plugin)                  │
+│                                 │
+│  Provides:                      │
+│  • CustomerService              │
+│  • OpportunityService           │
+│                                 │
+│  Extension Points:              │
+│  • customer_enrichment          │
+│  • customer_validator           │
+│  • opportunity_scoring          │
+└──────────┬──────────────────────┘
+           │
+           │ Depends On
+           ▼
+┌─────────────────────────────────┐
+│  com.objectstack.driver.postgres│
+│  Storage Driver                 │
+└─────────────────────────────────┘
+
+           │ Extended By
+           ▼
+┌─────────────────────────────────┐
+│  com.acme.crm.email-integration │
+│  Email Plugin                   │
+│                                 │
+│  Extends:                       │
+│  • customer_enrichment          │
+└─────────────────────────────────┘
+
+           │ Optional
+           ▼
+┌─────────────────────────────────┐
+│  com.acme.analytics.basic       │
+│  Analytics Plugin               │
+└─────────────────────────────────┘
+```
+
+## Usage
+
+### Installing the Plugin
+
+```bash
+npm install @acme/crm-advanced
+```
+
+### Configuration
+
+```typescript
+// objectstack.config.ts
+export default {
+  plugins: [
+    {
+      id: 'com.acme.crm.advanced',
+      config: {
+        apiEndpoint: 'https://api.acme.com',
+        syncInterval: 3600,
+        enableAudit: true,
+        apiKey: process.env.ACME_API_KEY,
+      },
+    },
+  ],
+};
+```
+
+### Using the Customer Service Interface
+
+```typescript
+// In another plugin
+export class MyPlugin implements Plugin {
+  name = 'com.example.my-plugin';
+  dependencies = ['com.acme.crm.advanced'];
+  
+  async start(ctx: PluginContext) {
+    // Get the customer service
+    const customerService = ctx.getService('customer-service');
+    
+    // Use the interface
+    const customer = await customerService.getCustomer('123');
+    console.log(customer);
+    
+    // Listen to events
+    ctx.hook('crm:customerCreated', async (event) => {
+      console.log('New customer:', event.data);
+    });
+  }
+}
+```
+
+### Extending the Plugin
+
+```typescript
+// Email enrichment plugin
+const manifest: ObjectStackManifest = {
+  id: 'com.acme.crm.email-enrichment',
+  
+  capabilities: {
+    requires: [
+      {
+        pluginId: 'com.acme.crm.advanced',
+        version: '^2.0.0',
+      },
+    ],
+    
+    extensions: [
+      {
+        targetPluginId: 'com.acme.crm.advanced',
+        extensionPointId: 'com.acme.crm.extension.customer_enrichment',
+        implementation: './enrichers/email-enricher.ts',
+        priority: 100,
+      },
+    ],
+  },
+};
+```
+
+## Documentation
+
+For more information on the plugin ecosystem:
+
+- [Plugin Ecosystem Architecture](/docs/developers/plugin-ecosystem)
+- [Writing Plugins](/docs/developers/writing-plugins)
+- [Plugin Capability Protocol](/docs/references/system/plugin-capability)
+- [Plugin Registry](/docs/references/hub/plugin-registry)
+
+## License
+
+Apache-2.0
diff --git a/examples/plugin-advanced-crm/objectstack.config.ts b/examples/plugin-advanced-crm/objectstack.config.ts
new file mode 100644
index 000000000..0621e3705
--- /dev/null
+++ b/examples/plugin-advanced-crm/objectstack.config.ts
@@ -0,0 +1,397 @@
+import { ObjectStackManifest } from '@objectstack/spec/system';
+
+/**
+ * Advanced CRM Plugin Example
+ * 
+ * This example demonstrates a comprehensive plugin manifest that:
+ * - Implements standard protocols
+ * - Provides interfaces for other plugins
+ * - Depends on other plugins
+ * - Defines extension points
+ * - Uses proper naming conventions
+ */
+const CRMPlugin: ObjectStackManifest = {
+  // Basic Information
+  id: 'com.acme.crm.advanced',
+  name: 'ACME Advanced CRM',
+  version: '2.1.0',
+  type: 'plugin',
+  description: 'Comprehensive customer relationship management with advanced features',
+
+  // Dependencies on NPM packages
+  dependencies: {
+    '@objectstack/spec': '^0.6.0',
+    '@objectstack/driver-postgres': '^1.0.0',
+  },
+
+  // Required System Permissions
+  permissions: [
+    'system.user.read',
+    'system.data.write',
+    'system.data.read',
+    'network.http.request',
+  ],
+
+  // Plugin Configuration Schema
+  configuration: {
+    title: 'CRM Configuration',
+    properties: {
+      apiEndpoint: {
+        type: 'string',
+        default: 'https://api.acme.com',
+        description: 'External API endpoint for data synchronization',
+      },
+      syncInterval: {
+        type: 'number',
+        default: 3600,
+        description: 'Sync interval in seconds',
+      },
+      enableAudit: {
+        type: 'boolean',
+        default: true,
+        description: 'Enable audit trail for customer data changes',
+      },
+      apiKey: {
+        type: 'string',
+        secret: true,
+        description: 'API key for external service integration',
+      },
+    },
+  },
+
+  // Plugin Capability Declaration
+  capabilities: {
+    // Protocols This Plugin Implements
+    implements: [
+      {
+        protocol: {
+          id: 'com.objectstack.protocol.storage.v1',
+          label: 'Storage Protocol v1',
+          version: { major: 1, minor: 0, patch: 0 },
+          description: 'Standard data storage and retrieval operations',
+        },
+        conformance: 'full',
+        certified: true,
+        certificationDate: '2024-01-15T00:00:00Z',
+      },
+      {
+        protocol: {
+          id: 'com.objectstack.protocol.sync.v1',
+          label: 'Data Sync Protocol v1',
+          version: { major: 1, minor: 0, patch: 0 },
+          description: 'Bidirectional data synchronization',
+        },
+        conformance: 'partial',
+        implementedFeatures: [
+          'incremental_sync',
+          'conflict_resolution',
+          'batch_operations',
+        ],
+        features: [
+          {
+            name: 'real_time_sync',
+            enabled: false,
+            description: 'Real-time synchronization via websockets',
+            sinceVersion: '2.0.0',
+          },
+          {
+            name: 'batch_operations',
+            enabled: true,
+            description: 'Batch sync operations for performance',
+          },
+        ],
+      },
+    ],
+
+    // Interfaces This Plugin Provides
+    provides: [
+      {
+        id: 'com.acme.crm.interface.customer_service',
+        name: 'CustomerService',
+        description: 'Customer data management service',
+        version: { major: 2, minor: 1, patch: 0 },
+        stability: 'stable',
+
+        methods: [
+          {
+            name: 'getCustomer',
+            description: 'Retrieve a customer by ID',
+            parameters: [
+              {
+                name: 'id',
+                type: 'string',
+                required: true,
+                description: 'Customer unique identifier',
+              },
+            ],
+            returnType: 'Customer',
+            async: true,
+          },
+          {
+            name: 'searchCustomers',
+            description: 'Search customers with filters',
+            parameters: [
+              {
+                name: 'query',
+                type: 'CustomerSearchQuery',
+                required: true,
+              },
+              {
+                name: 'options',
+                type: 'SearchOptions',
+                required: false,
+              },
+            ],
+            returnType: 'Customer[]',
+            async: true,
+          },
+          {
+            name: 'createCustomer',
+            description: 'Create a new customer',
+            parameters: [
+              {
+                name: 'data',
+                type: 'CustomerInput',
+                required: true,
+              },
+            ],
+            returnType: 'Customer',
+            async: true,
+          },
+          {
+            name: 'updateCustomer',
+            description: 'Update customer information',
+            parameters: [
+              {
+                name: 'id',
+                type: 'string',
+                required: true,
+              },
+              {
+                name: 'data',
+                type: 'Partial<CustomerInput>',
+                required: true,
+              },
+            ],
+            returnType: 'Customer',
+            async: true,
+          },
+        ],
+
+        events: [
+          {
+            name: 'customerCreated',
+            description: 'Fired when a new customer is created',
+            payload: 'Customer',
+          },
+          {
+            name: 'customerUpdated',
+            description: 'Fired when customer data is updated',
+            payload: 'CustomerUpdateEvent',
+          },
+          {
+            name: 'customerDeleted',
+            description: 'Fired when a customer is deleted',
+            payload: 'CustomerDeleteEvent',
+          },
+        ],
+      },
+
+      {
+        id: 'com.acme.crm.interface.opportunity_service',
+        name: 'OpportunityService',
+        description: 'Sales opportunity management',
+        version: { major: 1, minor: 0, patch: 0 },
+        stability: 'stable',
+
+        methods: [
+          {
+            name: 'getOpportunity',
+            parameters: [{ name: 'id', type: 'string', required: true }],
+            returnType: 'Opportunity',
+            async: true,
+          },
+          {
+            name: 'createOpportunity',
+            parameters: [{ name: 'data', type: 'OpportunityInput', required: true }],
+            returnType: 'Opportunity',
+            async: true,
+          },
+        ],
+
+        events: [
+          {
+            name: 'opportunityStageChanged',
+            description: 'Fired when opportunity stage is updated',
+            payload: 'OpportunityStageEvent',
+          },
+        ],
+      },
+    ],
+
+    // Dependencies on Other Plugins
+    requires: [
+      {
+        pluginId: 'com.objectstack.driver.postgres',
+        version: '^1.0.0',
+        optional: false,
+        reason: 'Primary data storage backend',
+        requiredCapabilities: [
+          'com.objectstack.protocol.storage.v1',
+          'com.objectstack.protocol.transactions.v1',
+        ],
+      },
+      {
+        pluginId: 'com.objectstack.auth.oauth2',
+        version: '>=2.0.0 <3.0.0',
+        optional: false,
+        reason: 'OAuth2 authentication for external API integration',
+      },
+      {
+        pluginId: 'com.acme.analytics.basic',
+        version: '^1.5.0',
+        optional: true,
+        reason: 'Enhanced analytics and reporting features',
+        requiredCapabilities: [
+          'com.acme.protocol.metrics.v1',
+        ],
+      },
+    ],
+
+    // Extension Points This Plugin Defines
+    extensionPoints: [
+      {
+        id: 'com.acme.crm.extension.customer_enrichment',
+        name: 'Customer Data Enrichment',
+        description: 'Allows other plugins to enrich customer data from external sources',
+        type: 'transformer',
+        cardinality: 'multiple',
+        contract: {
+          input: 'Customer',
+          output: 'EnrichedCustomer',
+          signature: '(customer: Customer) => Promise<Partial<Customer>>',
+        },
+      },
+      {
+        id: 'com.acme.crm.extension.customer_validator',
+        name: 'Customer Data Validator',
+        description: 'Custom validation rules for customer data',
+        type: 'validator',
+        cardinality: 'multiple',
+        contract: {
+          input: 'Customer',
+          output: 'ValidationResult',
+          signature: '(customer: Customer) => ValidationResult | Promise<ValidationResult>',
+        },
+      },
+      {
+        id: 'com.acme.crm.extension.opportunity_scoring',
+        name: 'Opportunity Scoring Engine',
+        description: 'Calculate opportunity win probability',
+        type: 'provider',
+        cardinality: 'single',
+        contract: {
+          input: 'Opportunity',
+          output: 'OpportunityScore',
+        },
+      },
+      {
+        id: 'com.acme.crm.extension.dashboard_widget',
+        name: 'Dashboard Widget',
+        description: 'Custom widgets for CRM dashboard',
+        type: 'widget',
+        cardinality: 'multiple',
+        contract: {
+          signature: 'React.ComponentType<WidgetProps>',
+        },
+      },
+    ],
+
+    // Extensions This Plugin Contributes to Other Plugins
+    extensions: [
+      {
+        targetPluginId: 'com.objectstack.ui.dashboard',
+        extensionPointId: 'com.objectstack.ui.extension.widget',
+        implementation: './widgets/customer-summary.tsx',
+        priority: 50,
+      },
+    ],
+  },
+
+  // Contribution Points
+  contributes: {
+    // Custom Metadata Kinds
+    kinds: [
+      {
+        id: 'crm.customer',
+        globs: ['**/*.customer.json', '**/*.customer.ts'],
+        description: 'Customer data definition files',
+      },
+    ],
+
+    // System Event Subscriptions
+    events: [
+      'system:plugin:installed',
+      'system:plugin:uninstalled',
+      'data:record:beforeCreate',
+      'data:record:afterCreate',
+    ],
+
+    // UI Menu Contributions
+    menus: {
+      'sidebar/main': [
+        {
+          id: 'open_crm_dashboard',
+          label: 'CRM Dashboard',
+          command: 'crm.openDashboard',
+        },
+        {
+          id: 'open_customers',
+          label: 'Customers',
+          command: 'crm.openCustomers',
+        },
+      ],
+    },
+
+    // Custom Actions
+    actions: [
+      {
+        name: 'sync_customers',
+        label: 'Sync Customers',
+        description: 'Manually trigger customer data synchronization',
+        input: {
+          fullSync: 'boolean',
+        },
+        output: {
+          syncedCount: 'number',
+          errors: 'string[]',
+        },
+      },
+    ],
+  },
+
+  // Data Model Definitions
+  objects: ['./src/objects/*.object.ts'],
+
+  // Initial Seed Data
+  data: [
+    {
+      object: 'crm_customer_status',
+      records: [
+        { name: 'active', label: 'Active', sort_order: 1 },
+        { name: 'inactive', label: 'Inactive', sort_order: 2 },
+        { name: 'prospect', label: 'Prospect', sort_order: 3 },
+      ],
+      mode: 'upsert',
+    },
+  ],
+
+  // Extension Entry Points
+  extensions: {
+    runtime: {
+      entry: './src/index.ts',
+    },
+  },
+};
+
+export default CRMPlugin;
diff --git a/packages/spec/json-schema/hub/ComposerResponse.json b/packages/spec/json-schema/hub/ComposerResponse.json
index bc7f6a74a..e00931899 100644
--- a/packages/spec/json-schema/hub/ComposerResponse.json
+++ b/packages/spec/json-schema/hub/ComposerResponse.json
@@ -385,6 +385,411 @@
               },
               "description": "Initial seed data"
             },
+            "capabilities": {
+              "type": "object",
+              "properties": {
+                "implements": {
+                  "type": "array",
+                  "items": {
+                    "type": "object",
+                    "properties": {
+                      "protocol": {
+                        "type": "object",
+                        "properties": {
+                          "id": {
+                            "type": "string",
+                            "pattern": "^([a-z][a-z0-9]*\\.)+protocol\\.[a-z][a-z0-9._]*\\.v\\d+$",
+                            "description": "Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1)"
+                          },
+                          "label": {
+                            "type": "string"
+                          },
+                          "version": {
+                            "type": "object",
+                            "properties": {
+                              "major": {
+                                "type": "integer",
+                                "minimum": 0
+                              },
+                              "minor": {
+                                "type": "integer",
+                                "minimum": 0
+                              },
+                              "patch": {
+                                "type": "integer",
+                                "minimum": 0
+                              }
+                            },
+                            "required": [
+                              "major",
+                              "minor",
+                              "patch"
+                            ],
+                            "additionalProperties": false,
+                            "description": "Semantic version of the protocol"
+                          },
+                          "specification": {
+                            "type": "string",
+                            "description": "URL or path to protocol specification"
+                          },
+                          "description": {
+                            "type": "string"
+                          }
+                        },
+                        "required": [
+                          "id",
+                          "label",
+                          "version"
+                        ],
+                        "additionalProperties": false
+                      },
+                      "conformance": {
+                        "type": "string",
+                        "enum": [
+                          "full",
+                          "partial",
+                          "experimental",
+                          "deprecated"
+                        ],
+                        "description": "Level of protocol conformance",
+                        "default": "full"
+                      },
+                      "implementedFeatures": {
+                        "type": "array",
+                        "items": {
+                          "type": "string"
+                        },
+                        "description": "List of implemented feature names"
+                      },
+                      "features": {
+                        "type": "array",
+                        "items": {
+                          "type": "object",
+                          "properties": {
+                            "name": {
+                              "type": "string",
+                              "description": "Feature identifier within the protocol"
+                            },
+                            "enabled": {
+                              "type": "boolean",
+                              "default": true
+                            },
+                            "description": {
+                              "type": "string"
+                            },
+                            "sinceVersion": {
+                              "type": "string",
+                              "description": "Version when this feature was added"
+                            },
+                            "deprecatedSince": {
+                              "type": "string",
+                              "description": "Version when deprecated"
+                            }
+                          },
+                          "required": [
+                            "name"
+                          ],
+                          "additionalProperties": false
+                        }
+                      },
+                      "metadata": {
+                        "type": "object",
+                        "additionalProperties": {}
+                      },
+                      "certified": {
+                        "type": "boolean",
+                        "default": false,
+                        "description": "Has passed official conformance tests"
+                      },
+                      "certificationDate": {
+                        "type": "string",
+                        "format": "date-time"
+                      }
+                    },
+                    "required": [
+                      "protocol"
+                    ],
+                    "additionalProperties": false
+                  },
+                  "description": "List of protocols this plugin conforms to"
+                },
+                "provides": {
+                  "type": "array",
+                  "items": {
+                    "type": "object",
+                    "properties": {
+                      "id": {
+                        "type": "string",
+                        "pattern": "^([a-z][a-z0-9]*\\.)+interface\\.[a-z][a-z0-9._]+$",
+                        "description": "Unique interface identifier"
+                      },
+                      "name": {
+                        "type": "string"
+                      },
+                      "description": {
+                        "type": "string"
+                      },
+                      "version": {
+                        "type": "object",
+                        "properties": {
+                          "major": {
+                            "type": "integer",
+                            "minimum": 0
+                          },
+                          "minor": {
+                            "type": "integer",
+                            "minimum": 0
+                          },
+                          "patch": {
+                            "type": "integer",
+                            "minimum": 0
+                          }
+                        },
+                        "required": [
+                          "major",
+                          "minor",
+                          "patch"
+                        ],
+                        "additionalProperties": false,
+                        "description": "Semantic version of the protocol"
+                      },
+                      "methods": {
+                        "type": "array",
+                        "items": {
+                          "type": "object",
+                          "properties": {
+                            "name": {
+                              "type": "string",
+                              "description": "Method name"
+                            },
+                            "description": {
+                              "type": "string"
+                            },
+                            "parameters": {
+                              "type": "array",
+                              "items": {
+                                "type": "object",
+                                "properties": {
+                                  "name": {
+                                    "type": "string"
+                                  },
+                                  "type": {
+                                    "type": "string",
+                                    "description": "Type notation (e.g., string, number, User)"
+                                  },
+                                  "required": {
+                                    "type": "boolean",
+                                    "default": true
+                                  },
+                                  "description": {
+                                    "type": "string"
+                                  }
+                                },
+                                "required": [
+                                  "name",
+                                  "type"
+                                ],
+                                "additionalProperties": false
+                              }
+                            },
+                            "returnType": {
+                              "type": "string",
+                              "description": "Return value type"
+                            },
+                            "async": {
+                              "type": "boolean",
+                              "default": false,
+                              "description": "Whether method returns a Promise"
+                            }
+                          },
+                          "required": [
+                            "name"
+                          ],
+                          "additionalProperties": false
+                        }
+                      },
+                      "events": {
+                        "type": "array",
+                        "items": {
+                          "type": "object",
+                          "properties": {
+                            "name": {
+                              "type": "string",
+                              "description": "Event name"
+                            },
+                            "description": {
+                              "type": "string"
+                            },
+                            "payload": {
+                              "type": "string",
+                              "description": "Event payload type"
+                            }
+                          },
+                          "required": [
+                            "name"
+                          ],
+                          "additionalProperties": false
+                        }
+                      },
+                      "stability": {
+                        "type": "string",
+                        "enum": [
+                          "stable",
+                          "beta",
+                          "alpha",
+                          "experimental"
+                        ],
+                        "default": "stable"
+                      }
+                    },
+                    "required": [
+                      "id",
+                      "name",
+                      "version",
+                      "methods"
+                    ],
+                    "additionalProperties": false
+                  },
+                  "description": "Services/APIs this plugin offers to others"
+                },
+                "requires": {
+                  "type": "array",
+                  "items": {
+                    "type": "object",
+                    "properties": {
+                      "pluginId": {
+                        "type": "string",
+                        "pattern": "^([a-z][a-z0-9]*\\.)+[a-z][a-z0-9-]+$",
+                        "description": "Required plugin identifier"
+                      },
+                      "version": {
+                        "type": "string",
+                        "description": "Semantic version constraint"
+                      },
+                      "optional": {
+                        "type": "boolean",
+                        "default": false
+                      },
+                      "reason": {
+                        "type": "string"
+                      },
+                      "requiredCapabilities": {
+                        "type": "array",
+                        "items": {
+                          "type": "string"
+                        },
+                        "description": "Protocol IDs the dependency must support"
+                      }
+                    },
+                    "required": [
+                      "pluginId",
+                      "version"
+                    ],
+                    "additionalProperties": false
+                  },
+                  "description": "Required plugins and their capabilities"
+                },
+                "extensionPoints": {
+                  "type": "array",
+                  "items": {
+                    "type": "object",
+                    "properties": {
+                      "id": {
+                        "type": "string",
+                        "pattern": "^([a-z][a-z0-9]*\\.)+extension\\.[a-z][a-z0-9._]+$",
+                        "description": "Unique extension point identifier"
+                      },
+                      "name": {
+                        "type": "string"
+                      },
+                      "description": {
+                        "type": "string"
+                      },
+                      "type": {
+                        "type": "string",
+                        "enum": [
+                          "action",
+                          "hook",
+                          "widget",
+                          "provider",
+                          "transformer",
+                          "validator",
+                          "decorator"
+                        ]
+                      },
+                      "contract": {
+                        "type": "object",
+                        "properties": {
+                          "input": {
+                            "type": "string",
+                            "description": "Input type/schema"
+                          },
+                          "output": {
+                            "type": "string",
+                            "description": "Output type/schema"
+                          },
+                          "signature": {
+                            "type": "string",
+                            "description": "Function signature if applicable"
+                          }
+                        },
+                        "additionalProperties": false
+                      },
+                      "cardinality": {
+                        "type": "string",
+                        "enum": [
+                          "single",
+                          "multiple"
+                        ],
+                        "default": "multiple",
+                        "description": "Whether multiple extensions can register to this point"
+                      }
+                    },
+                    "required": [
+                      "id",
+                      "name",
+                      "type"
+                    ],
+                    "additionalProperties": false
+                  },
+                  "description": "Points where other plugins can extend this plugin"
+                },
+                "extensions": {
+                  "type": "array",
+                  "items": {
+                    "type": "object",
+                    "properties": {
+                      "targetPluginId": {
+                        "type": "string",
+                        "description": "Plugin ID being extended"
+                      },
+                      "extensionPointId": {
+                        "type": "string",
+                        "description": "Extension point identifier"
+                      },
+                      "implementation": {
+                        "type": "string",
+                        "description": "Path to implementation module"
+                      },
+                      "priority": {
+                        "type": "integer",
+                        "default": 100,
+                        "description": "Registration priority (lower = higher priority)"
+                      }
+                    },
+                    "required": [
+                      "targetPluginId",
+                      "extensionPointId",
+                      "implementation"
+                    ],
+                    "additionalProperties": false
+                  },
+                  "description": "Extensions contributed to other plugins"
+                }
+              },
+              "additionalProperties": false,
+              "description": "Plugin capability declarations for interoperability"
+            },
             "extensions": {
               "type": "object",
               "additionalProperties": {},
diff --git a/packages/spec/json-schema/hub/PluginInstallConfig.json b/packages/spec/json-schema/hub/PluginInstallConfig.json
new file mode 100644
index 000000000..a86ce6e6a
--- /dev/null
+++ b/packages/spec/json-schema/hub/PluginInstallConfig.json
@@ -0,0 +1,53 @@
+{
+  "$ref": "#/definitions/PluginInstallConfig",
+  "definitions": {
+    "PluginInstallConfig": {
+      "type": "object",
+      "properties": {
+        "pluginId": {
+          "type": "string"
+        },
+        "version": {
+          "type": "string",
+          "description": "Defaults to latest"
+        },
+        "config": {
+          "type": "object",
+          "additionalProperties": {}
+        },
+        "autoUpdate": {
+          "type": "boolean",
+          "default": false
+        },
+        "options": {
+          "type": "object",
+          "properties": {
+            "skipDependencies": {
+              "type": "boolean",
+              "default": false
+            },
+            "force": {
+              "type": "boolean",
+              "default": false
+            },
+            "target": {
+              "type": "string",
+              "enum": [
+                "system",
+                "space",
+                "user"
+              ],
+              "default": "space"
+            }
+          },
+          "additionalProperties": false
+        }
+      },
+      "required": [
+        "pluginId"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/hub/PluginQualityMetrics.json b/packages/spec/json-schema/hub/PluginQualityMetrics.json
new file mode 100644
index 000000000..7ba64ecaf
--- /dev/null
+++ b/packages/spec/json-schema/hub/PluginQualityMetrics.json
@@ -0,0 +1,101 @@
+{
+  "$ref": "#/definitions/PluginQualityMetrics",
+  "definitions": {
+    "PluginQualityMetrics": {
+      "type": "object",
+      "properties": {
+        "testCoverage": {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 100
+        },
+        "documentationScore": {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 100
+        },
+        "codeQuality": {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 100
+        },
+        "securityScan": {
+          "type": "object",
+          "properties": {
+            "lastScanDate": {
+              "type": "string",
+              "format": "date-time"
+            },
+            "vulnerabilities": {
+              "type": "object",
+              "properties": {
+                "critical": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "high": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "medium": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "low": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                }
+              },
+              "additionalProperties": false
+            },
+            "passed": {
+              "type": "boolean",
+              "default": false
+            }
+          },
+          "additionalProperties": false
+        },
+        "conformanceTests": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "protocolId": {
+                "type": "string",
+                "description": "Protocol being tested"
+              },
+              "passed": {
+                "type": "boolean"
+              },
+              "totalTests": {
+                "type": "integer",
+                "minimum": 0
+              },
+              "passedTests": {
+                "type": "integer",
+                "minimum": 0
+              },
+              "lastRunDate": {
+                "type": "string",
+                "format": "date-time"
+              }
+            },
+            "required": [
+              "protocolId",
+              "passed",
+              "totalTests",
+              "passedTests"
+            ],
+            "additionalProperties": false
+          }
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/hub/PluginRegistryEntry.json b/packages/spec/json-schema/hub/PluginRegistryEntry.json
new file mode 100644
index 000000000..23917ce20
--- /dev/null
+++ b/packages/spec/json-schema/hub/PluginRegistryEntry.json
@@ -0,0 +1,833 @@
+{
+  "$ref": "#/definitions/PluginRegistryEntry",
+  "definitions": {
+    "PluginRegistryEntry": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "type": "string",
+          "pattern": "^([a-z][a-z0-9]*\\.)+[a-z][a-z0-9-]+$",
+          "description": "Plugin identifier (reverse domain notation)"
+        },
+        "version": {
+          "type": "string",
+          "pattern": "^\\d+\\.\\d+\\.\\d+$"
+        },
+        "name": {
+          "type": "string"
+        },
+        "description": {
+          "type": "string"
+        },
+        "readme": {
+          "type": "string"
+        },
+        "category": {
+          "type": "string",
+          "enum": [
+            "data",
+            "integration",
+            "ui",
+            "analytics",
+            "security",
+            "automation",
+            "ai",
+            "utility",
+            "driver",
+            "gateway",
+            "adapter"
+          ]
+        },
+        "tags": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        },
+        "vendor": {
+          "type": "object",
+          "properties": {
+            "id": {
+              "type": "string",
+              "pattern": "^[a-z][a-z0-9]*(\\.[a-z][a-z0-9]*)+$",
+              "description": "Vendor identifier (reverse domain)"
+            },
+            "name": {
+              "type": "string"
+            },
+            "website": {
+              "type": "string",
+              "format": "uri"
+            },
+            "email": {
+              "type": "string",
+              "format": "email"
+            },
+            "verified": {
+              "type": "boolean",
+              "default": false,
+              "description": "Whether vendor is verified by ObjectStack"
+            },
+            "trustLevel": {
+              "type": "string",
+              "enum": [
+                "official",
+                "verified",
+                "community",
+                "unverified"
+              ],
+              "default": "unverified"
+            }
+          },
+          "required": [
+            "id",
+            "name"
+          ],
+          "additionalProperties": false
+        },
+        "capabilities": {
+          "type": "object",
+          "properties": {
+            "implements": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "protocol": {
+                    "type": "object",
+                    "properties": {
+                      "id": {
+                        "type": "string",
+                        "pattern": "^([a-z][a-z0-9]*\\.)+protocol\\.[a-z][a-z0-9._]*\\.v\\d+$",
+                        "description": "Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1)"
+                      },
+                      "label": {
+                        "type": "string"
+                      },
+                      "version": {
+                        "type": "object",
+                        "properties": {
+                          "major": {
+                            "type": "integer",
+                            "minimum": 0
+                          },
+                          "minor": {
+                            "type": "integer",
+                            "minimum": 0
+                          },
+                          "patch": {
+                            "type": "integer",
+                            "minimum": 0
+                          }
+                        },
+                        "required": [
+                          "major",
+                          "minor",
+                          "patch"
+                        ],
+                        "additionalProperties": false,
+                        "description": "Semantic version of the protocol"
+                      },
+                      "specification": {
+                        "type": "string",
+                        "description": "URL or path to protocol specification"
+                      },
+                      "description": {
+                        "type": "string"
+                      }
+                    },
+                    "required": [
+                      "id",
+                      "label",
+                      "version"
+                    ],
+                    "additionalProperties": false
+                  },
+                  "conformance": {
+                    "type": "string",
+                    "enum": [
+                      "full",
+                      "partial",
+                      "experimental",
+                      "deprecated"
+                    ],
+                    "description": "Level of protocol conformance",
+                    "default": "full"
+                  },
+                  "implementedFeatures": {
+                    "type": "array",
+                    "items": {
+                      "type": "string"
+                    },
+                    "description": "List of implemented feature names"
+                  },
+                  "features": {
+                    "type": "array",
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "name": {
+                          "type": "string",
+                          "description": "Feature identifier within the protocol"
+                        },
+                        "enabled": {
+                          "type": "boolean",
+                          "default": true
+                        },
+                        "description": {
+                          "type": "string"
+                        },
+                        "sinceVersion": {
+                          "type": "string",
+                          "description": "Version when this feature was added"
+                        },
+                        "deprecatedSince": {
+                          "type": "string",
+                          "description": "Version when deprecated"
+                        }
+                      },
+                      "required": [
+                        "name"
+                      ],
+                      "additionalProperties": false
+                    }
+                  },
+                  "metadata": {
+                    "type": "object",
+                    "additionalProperties": {}
+                  },
+                  "certified": {
+                    "type": "boolean",
+                    "default": false,
+                    "description": "Has passed official conformance tests"
+                  },
+                  "certificationDate": {
+                    "type": "string",
+                    "format": "date-time"
+                  }
+                },
+                "required": [
+                  "protocol"
+                ],
+                "additionalProperties": false
+              },
+              "description": "List of protocols this plugin conforms to"
+            },
+            "provides": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "id": {
+                    "type": "string",
+                    "pattern": "^([a-z][a-z0-9]*\\.)+interface\\.[a-z][a-z0-9._]+$",
+                    "description": "Unique interface identifier"
+                  },
+                  "name": {
+                    "type": "string"
+                  },
+                  "description": {
+                    "type": "string"
+                  },
+                  "version": {
+                    "type": "object",
+                    "properties": {
+                      "major": {
+                        "type": "integer",
+                        "minimum": 0
+                      },
+                      "minor": {
+                        "type": "integer",
+                        "minimum": 0
+                      },
+                      "patch": {
+                        "type": "integer",
+                        "minimum": 0
+                      }
+                    },
+                    "required": [
+                      "major",
+                      "minor",
+                      "patch"
+                    ],
+                    "additionalProperties": false,
+                    "description": "Semantic version of the protocol"
+                  },
+                  "methods": {
+                    "type": "array",
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "name": {
+                          "type": "string",
+                          "description": "Method name"
+                        },
+                        "description": {
+                          "type": "string"
+                        },
+                        "parameters": {
+                          "type": "array",
+                          "items": {
+                            "type": "object",
+                            "properties": {
+                              "name": {
+                                "type": "string"
+                              },
+                              "type": {
+                                "type": "string",
+                                "description": "Type notation (e.g., string, number, User)"
+                              },
+                              "required": {
+                                "type": "boolean",
+                                "default": true
+                              },
+                              "description": {
+                                "type": "string"
+                              }
+                            },
+                            "required": [
+                              "name",
+                              "type"
+                            ],
+                            "additionalProperties": false
+                          }
+                        },
+                        "returnType": {
+                          "type": "string",
+                          "description": "Return value type"
+                        },
+                        "async": {
+                          "type": "boolean",
+                          "default": false,
+                          "description": "Whether method returns a Promise"
+                        }
+                      },
+                      "required": [
+                        "name"
+                      ],
+                      "additionalProperties": false
+                    }
+                  },
+                  "events": {
+                    "type": "array",
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "name": {
+                          "type": "string",
+                          "description": "Event name"
+                        },
+                        "description": {
+                          "type": "string"
+                        },
+                        "payload": {
+                          "type": "string",
+                          "description": "Event payload type"
+                        }
+                      },
+                      "required": [
+                        "name"
+                      ],
+                      "additionalProperties": false
+                    }
+                  },
+                  "stability": {
+                    "type": "string",
+                    "enum": [
+                      "stable",
+                      "beta",
+                      "alpha",
+                      "experimental"
+                    ],
+                    "default": "stable"
+                  }
+                },
+                "required": [
+                  "id",
+                  "name",
+                  "version",
+                  "methods"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Services/APIs this plugin offers to others"
+            },
+            "requires": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "pluginId": {
+                    "type": "string",
+                    "pattern": "^([a-z][a-z0-9]*\\.)+[a-z][a-z0-9-]+$",
+                    "description": "Required plugin identifier"
+                  },
+                  "version": {
+                    "type": "string",
+                    "description": "Semantic version constraint"
+                  },
+                  "optional": {
+                    "type": "boolean",
+                    "default": false
+                  },
+                  "reason": {
+                    "type": "string"
+                  },
+                  "requiredCapabilities": {
+                    "type": "array",
+                    "items": {
+                      "type": "string"
+                    },
+                    "description": "Protocol IDs the dependency must support"
+                  }
+                },
+                "required": [
+                  "pluginId",
+                  "version"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Required plugins and their capabilities"
+            },
+            "extensionPoints": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "id": {
+                    "type": "string",
+                    "pattern": "^([a-z][a-z0-9]*\\.)+extension\\.[a-z][a-z0-9._]+$",
+                    "description": "Unique extension point identifier"
+                  },
+                  "name": {
+                    "type": "string"
+                  },
+                  "description": {
+                    "type": "string"
+                  },
+                  "type": {
+                    "type": "string",
+                    "enum": [
+                      "action",
+                      "hook",
+                      "widget",
+                      "provider",
+                      "transformer",
+                      "validator",
+                      "decorator"
+                    ]
+                  },
+                  "contract": {
+                    "type": "object",
+                    "properties": {
+                      "input": {
+                        "type": "string",
+                        "description": "Input type/schema"
+                      },
+                      "output": {
+                        "type": "string",
+                        "description": "Output type/schema"
+                      },
+                      "signature": {
+                        "type": "string",
+                        "description": "Function signature if applicable"
+                      }
+                    },
+                    "additionalProperties": false
+                  },
+                  "cardinality": {
+                    "type": "string",
+                    "enum": [
+                      "single",
+                      "multiple"
+                    ],
+                    "default": "multiple",
+                    "description": "Whether multiple extensions can register to this point"
+                  }
+                },
+                "required": [
+                  "id",
+                  "name",
+                  "type"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Points where other plugins can extend this plugin"
+            },
+            "extensions": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "targetPluginId": {
+                    "type": "string",
+                    "description": "Plugin ID being extended"
+                  },
+                  "extensionPointId": {
+                    "type": "string",
+                    "description": "Extension point identifier"
+                  },
+                  "implementation": {
+                    "type": "string",
+                    "description": "Path to implementation module"
+                  },
+                  "priority": {
+                    "type": "integer",
+                    "default": 100,
+                    "description": "Registration priority (lower = higher priority)"
+                  }
+                },
+                "required": [
+                  "targetPluginId",
+                  "extensionPointId",
+                  "implementation"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Extensions contributed to other plugins"
+            }
+          },
+          "additionalProperties": false
+        },
+        "compatibility": {
+          "type": "object",
+          "properties": {
+            "minObjectStackVersion": {
+              "type": "string"
+            },
+            "maxObjectStackVersion": {
+              "type": "string"
+            },
+            "nodeVersion": {
+              "type": "string"
+            },
+            "platforms": {
+              "type": "array",
+              "items": {
+                "type": "string",
+                "enum": [
+                  "linux",
+                  "darwin",
+                  "win32",
+                  "browser"
+                ]
+              }
+            }
+          },
+          "additionalProperties": false
+        },
+        "links": {
+          "type": "object",
+          "properties": {
+            "homepage": {
+              "type": "string",
+              "format": "uri"
+            },
+            "repository": {
+              "type": "string",
+              "format": "uri"
+            },
+            "documentation": {
+              "type": "string",
+              "format": "uri"
+            },
+            "bugs": {
+              "type": "string",
+              "format": "uri"
+            },
+            "changelog": {
+              "type": "string",
+              "format": "uri"
+            }
+          },
+          "additionalProperties": false
+        },
+        "media": {
+          "type": "object",
+          "properties": {
+            "icon": {
+              "type": "string",
+              "format": "uri"
+            },
+            "logo": {
+              "type": "string",
+              "format": "uri"
+            },
+            "screenshots": {
+              "type": "array",
+              "items": {
+                "type": "string",
+                "format": "uri"
+              }
+            },
+            "video": {
+              "type": "string",
+              "format": "uri"
+            }
+          },
+          "additionalProperties": false
+        },
+        "quality": {
+          "type": "object",
+          "properties": {
+            "testCoverage": {
+              "type": "number",
+              "minimum": 0,
+              "maximum": 100
+            },
+            "documentationScore": {
+              "type": "number",
+              "minimum": 0,
+              "maximum": 100
+            },
+            "codeQuality": {
+              "type": "number",
+              "minimum": 0,
+              "maximum": 100
+            },
+            "securityScan": {
+              "type": "object",
+              "properties": {
+                "lastScanDate": {
+                  "type": "string",
+                  "format": "date-time"
+                },
+                "vulnerabilities": {
+                  "type": "object",
+                  "properties": {
+                    "critical": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    },
+                    "high": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    },
+                    "medium": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    },
+                    "low": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    }
+                  },
+                  "additionalProperties": false
+                },
+                "passed": {
+                  "type": "boolean",
+                  "default": false
+                }
+              },
+              "additionalProperties": false
+            },
+            "conformanceTests": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "protocolId": {
+                    "type": "string",
+                    "description": "Protocol being tested"
+                  },
+                  "passed": {
+                    "type": "boolean"
+                  },
+                  "totalTests": {
+                    "type": "integer",
+                    "minimum": 0
+                  },
+                  "passedTests": {
+                    "type": "integer",
+                    "minimum": 0
+                  },
+                  "lastRunDate": {
+                    "type": "string",
+                    "format": "date-time"
+                  }
+                },
+                "required": [
+                  "protocolId",
+                  "passed",
+                  "totalTests",
+                  "passedTests"
+                ],
+                "additionalProperties": false
+              }
+            }
+          },
+          "additionalProperties": false
+        },
+        "statistics": {
+          "type": "object",
+          "properties": {
+            "downloads": {
+              "type": "integer",
+              "minimum": 0,
+              "default": 0
+            },
+            "downloadsLastMonth": {
+              "type": "integer",
+              "minimum": 0,
+              "default": 0
+            },
+            "activeInstallations": {
+              "type": "integer",
+              "minimum": 0,
+              "default": 0
+            },
+            "ratings": {
+              "type": "object",
+              "properties": {
+                "average": {
+                  "type": "number",
+                  "minimum": 0,
+                  "maximum": 5,
+                  "default": 0
+                },
+                "count": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "distribution": {
+                  "type": "object",
+                  "properties": {
+                    "1": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    },
+                    "2": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    },
+                    "3": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    },
+                    "4": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    },
+                    "5": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "default": 0
+                    }
+                  },
+                  "additionalProperties": false
+                }
+              },
+              "additionalProperties": false
+            },
+            "stars": {
+              "type": "integer",
+              "minimum": 0
+            },
+            "dependents": {
+              "type": "integer",
+              "minimum": 0,
+              "default": 0
+            }
+          },
+          "additionalProperties": false
+        },
+        "license": {
+          "type": "string",
+          "description": "SPDX license identifier"
+        },
+        "pricing": {
+          "type": "object",
+          "properties": {
+            "model": {
+              "type": "string",
+              "enum": [
+                "free",
+                "freemium",
+                "paid",
+                "enterprise"
+              ]
+            },
+            "price": {
+              "type": "number",
+              "minimum": 0
+            },
+            "currency": {
+              "type": "string",
+              "default": "USD"
+            },
+            "billingPeriod": {
+              "type": "string",
+              "enum": [
+                "one-time",
+                "monthly",
+                "yearly"
+              ]
+            }
+          },
+          "required": [
+            "model"
+          ],
+          "additionalProperties": false
+        },
+        "publishedAt": {
+          "type": "string",
+          "format": "date-time"
+        },
+        "updatedAt": {
+          "type": "string",
+          "format": "date-time"
+        },
+        "deprecated": {
+          "type": "boolean",
+          "default": false
+        },
+        "deprecationMessage": {
+          "type": "string"
+        },
+        "replacedBy": {
+          "type": "string",
+          "description": "Plugin ID that replaces this one"
+        },
+        "flags": {
+          "type": "object",
+          "properties": {
+            "experimental": {
+              "type": "boolean",
+              "default": false
+            },
+            "beta": {
+              "type": "boolean",
+              "default": false
+            },
+            "featured": {
+              "type": "boolean",
+              "default": false
+            },
+            "verified": {
+              "type": "boolean",
+              "default": false
+            }
+          },
+          "additionalProperties": false
+        }
+      },
+      "required": [
+        "id",
+        "version",
+        "name",
+        "vendor"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/hub/PluginSearchFilters.json b/packages/spec/json-schema/hub/PluginSearchFilters.json
new file mode 100644
index 000000000..dc3168ee4
--- /dev/null
+++ b/packages/spec/json-schema/hub/PluginSearchFilters.json
@@ -0,0 +1,91 @@
+{
+  "$ref": "#/definitions/PluginSearchFilters",
+  "definitions": {
+    "PluginSearchFilters": {
+      "type": "object",
+      "properties": {
+        "query": {
+          "type": "string"
+        },
+        "category": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        },
+        "tags": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        },
+        "trustLevel": {
+          "type": "array",
+          "items": {
+            "type": "string",
+            "enum": [
+              "official",
+              "verified",
+              "community",
+              "unverified"
+            ]
+          }
+        },
+        "implementsProtocols": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        },
+        "pricingModel": {
+          "type": "array",
+          "items": {
+            "type": "string",
+            "enum": [
+              "free",
+              "freemium",
+              "paid",
+              "enterprise"
+            ]
+          }
+        },
+        "minRating": {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 5
+        },
+        "sortBy": {
+          "type": "string",
+          "enum": [
+            "relevance",
+            "downloads",
+            "rating",
+            "updated",
+            "name"
+          ]
+        },
+        "sortOrder": {
+          "type": "string",
+          "enum": [
+            "asc",
+            "desc"
+          ],
+          "default": "desc"
+        },
+        "page": {
+          "type": "integer",
+          "minimum": 1,
+          "default": 1
+        },
+        "limit": {
+          "type": "integer",
+          "minimum": 1,
+          "maximum": 100,
+          "default": 20
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/hub/PluginStatistics.json b/packages/spec/json-schema/hub/PluginStatistics.json
new file mode 100644
index 000000000..48676226d
--- /dev/null
+++ b/packages/spec/json-schema/hub/PluginStatistics.json
@@ -0,0 +1,84 @@
+{
+  "$ref": "#/definitions/PluginStatistics",
+  "definitions": {
+    "PluginStatistics": {
+      "type": "object",
+      "properties": {
+        "downloads": {
+          "type": "integer",
+          "minimum": 0,
+          "default": 0
+        },
+        "downloadsLastMonth": {
+          "type": "integer",
+          "minimum": 0,
+          "default": 0
+        },
+        "activeInstallations": {
+          "type": "integer",
+          "minimum": 0,
+          "default": 0
+        },
+        "ratings": {
+          "type": "object",
+          "properties": {
+            "average": {
+              "type": "number",
+              "minimum": 0,
+              "maximum": 5,
+              "default": 0
+            },
+            "count": {
+              "type": "integer",
+              "minimum": 0,
+              "default": 0
+            },
+            "distribution": {
+              "type": "object",
+              "properties": {
+                "1": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "2": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "3": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "4": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                },
+                "5": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "default": 0
+                }
+              },
+              "additionalProperties": false
+            }
+          },
+          "additionalProperties": false
+        },
+        "stars": {
+          "type": "integer",
+          "minimum": 0
+        },
+        "dependents": {
+          "type": "integer",
+          "minimum": 0,
+          "default": 0
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/hub/PluginVendor.json b/packages/spec/json-schema/hub/PluginVendor.json
new file mode 100644
index 000000000..14fa240a8
--- /dev/null
+++ b/packages/spec/json-schema/hub/PluginVendor.json
@@ -0,0 +1,47 @@
+{
+  "$ref": "#/definitions/PluginVendor",
+  "definitions": {
+    "PluginVendor": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "type": "string",
+          "pattern": "^[a-z][a-z0-9]*(\\.[a-z][a-z0-9]*)+$",
+          "description": "Vendor identifier (reverse domain)"
+        },
+        "name": {
+          "type": "string"
+        },
+        "website": {
+          "type": "string",
+          "format": "uri"
+        },
+        "email": {
+          "type": "string",
+          "format": "email"
+        },
+        "verified": {
+          "type": "boolean",
+          "default": false,
+          "description": "Whether vendor is verified by ObjectStack"
+        },
+        "trustLevel": {
+          "type": "string",
+          "enum": [
+            "official",
+            "verified",
+            "community",
+            "unverified"
+          ],
+          "default": "unverified"
+        }
+      },
+      "required": [
+        "id",
+        "name"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/CapabilityConformanceLevel.json b/packages/spec/json-schema/system/CapabilityConformanceLevel.json
new file mode 100644
index 000000000..9a2a7b051
--- /dev/null
+++ b/packages/spec/json-schema/system/CapabilityConformanceLevel.json
@@ -0,0 +1,16 @@
+{
+  "$ref": "#/definitions/CapabilityConformanceLevel",
+  "definitions": {
+    "CapabilityConformanceLevel": {
+      "type": "string",
+      "enum": [
+        "full",
+        "partial",
+        "experimental",
+        "deprecated"
+      ],
+      "description": "Level of protocol conformance"
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/ExtensionPoint.json b/packages/spec/json-schema/system/ExtensionPoint.json
new file mode 100644
index 000000000..8bd10ff88
--- /dev/null
+++ b/packages/spec/json-schema/system/ExtensionPoint.json
@@ -0,0 +1,67 @@
+{
+  "$ref": "#/definitions/ExtensionPoint",
+  "definitions": {
+    "ExtensionPoint": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "type": "string",
+          "pattern": "^([a-z][a-z0-9]*\\.)+extension\\.[a-z][a-z0-9._]+$",
+          "description": "Unique extension point identifier"
+        },
+        "name": {
+          "type": "string"
+        },
+        "description": {
+          "type": "string"
+        },
+        "type": {
+          "type": "string",
+          "enum": [
+            "action",
+            "hook",
+            "widget",
+            "provider",
+            "transformer",
+            "validator",
+            "decorator"
+          ]
+        },
+        "contract": {
+          "type": "object",
+          "properties": {
+            "input": {
+              "type": "string",
+              "description": "Input type/schema"
+            },
+            "output": {
+              "type": "string",
+              "description": "Output type/schema"
+            },
+            "signature": {
+              "type": "string",
+              "description": "Function signature if applicable"
+            }
+          },
+          "additionalProperties": false
+        },
+        "cardinality": {
+          "type": "string",
+          "enum": [
+            "single",
+            "multiple"
+          ],
+          "default": "multiple",
+          "description": "Whether multiple extensions can register to this point"
+        }
+      },
+      "required": [
+        "id",
+        "name",
+        "type"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/Manifest.json b/packages/spec/json-schema/system/Manifest.json
index 6e0998b92..2b606e230 100644
--- a/packages/spec/json-schema/system/Manifest.json
+++ b/packages/spec/json-schema/system/Manifest.json
@@ -379,6 +379,411 @@
           },
           "description": "Initial seed data"
         },
+        "capabilities": {
+          "type": "object",
+          "properties": {
+            "implements": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "protocol": {
+                    "type": "object",
+                    "properties": {
+                      "id": {
+                        "type": "string",
+                        "pattern": "^([a-z][a-z0-9]*\\.)+protocol\\.[a-z][a-z0-9._]*\\.v\\d+$",
+                        "description": "Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1)"
+                      },
+                      "label": {
+                        "type": "string"
+                      },
+                      "version": {
+                        "type": "object",
+                        "properties": {
+                          "major": {
+                            "type": "integer",
+                            "minimum": 0
+                          },
+                          "minor": {
+                            "type": "integer",
+                            "minimum": 0
+                          },
+                          "patch": {
+                            "type": "integer",
+                            "minimum": 0
+                          }
+                        },
+                        "required": [
+                          "major",
+                          "minor",
+                          "patch"
+                        ],
+                        "additionalProperties": false,
+                        "description": "Semantic version of the protocol"
+                      },
+                      "specification": {
+                        "type": "string",
+                        "description": "URL or path to protocol specification"
+                      },
+                      "description": {
+                        "type": "string"
+                      }
+                    },
+                    "required": [
+                      "id",
+                      "label",
+                      "version"
+                    ],
+                    "additionalProperties": false
+                  },
+                  "conformance": {
+                    "type": "string",
+                    "enum": [
+                      "full",
+                      "partial",
+                      "experimental",
+                      "deprecated"
+                    ],
+                    "description": "Level of protocol conformance",
+                    "default": "full"
+                  },
+                  "implementedFeatures": {
+                    "type": "array",
+                    "items": {
+                      "type": "string"
+                    },
+                    "description": "List of implemented feature names"
+                  },
+                  "features": {
+                    "type": "array",
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "name": {
+                          "type": "string",
+                          "description": "Feature identifier within the protocol"
+                        },
+                        "enabled": {
+                          "type": "boolean",
+                          "default": true
+                        },
+                        "description": {
+                          "type": "string"
+                        },
+                        "sinceVersion": {
+                          "type": "string",
+                          "description": "Version when this feature was added"
+                        },
+                        "deprecatedSince": {
+                          "type": "string",
+                          "description": "Version when deprecated"
+                        }
+                      },
+                      "required": [
+                        "name"
+                      ],
+                      "additionalProperties": false
+                    }
+                  },
+                  "metadata": {
+                    "type": "object",
+                    "additionalProperties": {}
+                  },
+                  "certified": {
+                    "type": "boolean",
+                    "default": false,
+                    "description": "Has passed official conformance tests"
+                  },
+                  "certificationDate": {
+                    "type": "string",
+                    "format": "date-time"
+                  }
+                },
+                "required": [
+                  "protocol"
+                ],
+                "additionalProperties": false
+              },
+              "description": "List of protocols this plugin conforms to"
+            },
+            "provides": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "id": {
+                    "type": "string",
+                    "pattern": "^([a-z][a-z0-9]*\\.)+interface\\.[a-z][a-z0-9._]+$",
+                    "description": "Unique interface identifier"
+                  },
+                  "name": {
+                    "type": "string"
+                  },
+                  "description": {
+                    "type": "string"
+                  },
+                  "version": {
+                    "type": "object",
+                    "properties": {
+                      "major": {
+                        "type": "integer",
+                        "minimum": 0
+                      },
+                      "minor": {
+                        "type": "integer",
+                        "minimum": 0
+                      },
+                      "patch": {
+                        "type": "integer",
+                        "minimum": 0
+                      }
+                    },
+                    "required": [
+                      "major",
+                      "minor",
+                      "patch"
+                    ],
+                    "additionalProperties": false,
+                    "description": "Semantic version of the protocol"
+                  },
+                  "methods": {
+                    "type": "array",
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "name": {
+                          "type": "string",
+                          "description": "Method name"
+                        },
+                        "description": {
+                          "type": "string"
+                        },
+                        "parameters": {
+                          "type": "array",
+                          "items": {
+                            "type": "object",
+                            "properties": {
+                              "name": {
+                                "type": "string"
+                              },
+                              "type": {
+                                "type": "string",
+                                "description": "Type notation (e.g., string, number, User)"
+                              },
+                              "required": {
+                                "type": "boolean",
+                                "default": true
+                              },
+                              "description": {
+                                "type": "string"
+                              }
+                            },
+                            "required": [
+                              "name",
+                              "type"
+                            ],
+                            "additionalProperties": false
+                          }
+                        },
+                        "returnType": {
+                          "type": "string",
+                          "description": "Return value type"
+                        },
+                        "async": {
+                          "type": "boolean",
+                          "default": false,
+                          "description": "Whether method returns a Promise"
+                        }
+                      },
+                      "required": [
+                        "name"
+                      ],
+                      "additionalProperties": false
+                    }
+                  },
+                  "events": {
+                    "type": "array",
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "name": {
+                          "type": "string",
+                          "description": "Event name"
+                        },
+                        "description": {
+                          "type": "string"
+                        },
+                        "payload": {
+                          "type": "string",
+                          "description": "Event payload type"
+                        }
+                      },
+                      "required": [
+                        "name"
+                      ],
+                      "additionalProperties": false
+                    }
+                  },
+                  "stability": {
+                    "type": "string",
+                    "enum": [
+                      "stable",
+                      "beta",
+                      "alpha",
+                      "experimental"
+                    ],
+                    "default": "stable"
+                  }
+                },
+                "required": [
+                  "id",
+                  "name",
+                  "version",
+                  "methods"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Services/APIs this plugin offers to others"
+            },
+            "requires": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "pluginId": {
+                    "type": "string",
+                    "pattern": "^([a-z][a-z0-9]*\\.)+[a-z][a-z0-9-]+$",
+                    "description": "Required plugin identifier"
+                  },
+                  "version": {
+                    "type": "string",
+                    "description": "Semantic version constraint"
+                  },
+                  "optional": {
+                    "type": "boolean",
+                    "default": false
+                  },
+                  "reason": {
+                    "type": "string"
+                  },
+                  "requiredCapabilities": {
+                    "type": "array",
+                    "items": {
+                      "type": "string"
+                    },
+                    "description": "Protocol IDs the dependency must support"
+                  }
+                },
+                "required": [
+                  "pluginId",
+                  "version"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Required plugins and their capabilities"
+            },
+            "extensionPoints": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "id": {
+                    "type": "string",
+                    "pattern": "^([a-z][a-z0-9]*\\.)+extension\\.[a-z][a-z0-9._]+$",
+                    "description": "Unique extension point identifier"
+                  },
+                  "name": {
+                    "type": "string"
+                  },
+                  "description": {
+                    "type": "string"
+                  },
+                  "type": {
+                    "type": "string",
+                    "enum": [
+                      "action",
+                      "hook",
+                      "widget",
+                      "provider",
+                      "transformer",
+                      "validator",
+                      "decorator"
+                    ]
+                  },
+                  "contract": {
+                    "type": "object",
+                    "properties": {
+                      "input": {
+                        "type": "string",
+                        "description": "Input type/schema"
+                      },
+                      "output": {
+                        "type": "string",
+                        "description": "Output type/schema"
+                      },
+                      "signature": {
+                        "type": "string",
+                        "description": "Function signature if applicable"
+                      }
+                    },
+                    "additionalProperties": false
+                  },
+                  "cardinality": {
+                    "type": "string",
+                    "enum": [
+                      "single",
+                      "multiple"
+                    ],
+                    "default": "multiple",
+                    "description": "Whether multiple extensions can register to this point"
+                  }
+                },
+                "required": [
+                  "id",
+                  "name",
+                  "type"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Points where other plugins can extend this plugin"
+            },
+            "extensions": {
+              "type": "array",
+              "items": {
+                "type": "object",
+                "properties": {
+                  "targetPluginId": {
+                    "type": "string",
+                    "description": "Plugin ID being extended"
+                  },
+                  "extensionPointId": {
+                    "type": "string",
+                    "description": "Extension point identifier"
+                  },
+                  "implementation": {
+                    "type": "string",
+                    "description": "Path to implementation module"
+                  },
+                  "priority": {
+                    "type": "integer",
+                    "default": 100,
+                    "description": "Registration priority (lower = higher priority)"
+                  }
+                },
+                "required": [
+                  "targetPluginId",
+                  "extensionPointId",
+                  "implementation"
+                ],
+                "additionalProperties": false
+              },
+              "description": "Extensions contributed to other plugins"
+            }
+          },
+          "additionalProperties": false,
+          "description": "Plugin capability declarations for interoperability"
+        },
         "extensions": {
           "type": "object",
           "additionalProperties": {},
diff --git a/packages/spec/json-schema/system/PluginCapability.json b/packages/spec/json-schema/system/PluginCapability.json
new file mode 100644
index 000000000..6396762bf
--- /dev/null
+++ b/packages/spec/json-schema/system/PluginCapability.json
@@ -0,0 +1,127 @@
+{
+  "$ref": "#/definitions/PluginCapability",
+  "definitions": {
+    "PluginCapability": {
+      "type": "object",
+      "properties": {
+        "protocol": {
+          "type": "object",
+          "properties": {
+            "id": {
+              "type": "string",
+              "pattern": "^([a-z][a-z0-9]*\\.)+protocol\\.[a-z][a-z0-9._]*\\.v\\d+$",
+              "description": "Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1)"
+            },
+            "label": {
+              "type": "string"
+            },
+            "version": {
+              "type": "object",
+              "properties": {
+                "major": {
+                  "type": "integer",
+                  "minimum": 0
+                },
+                "minor": {
+                  "type": "integer",
+                  "minimum": 0
+                },
+                "patch": {
+                  "type": "integer",
+                  "minimum": 0
+                }
+              },
+              "required": [
+                "major",
+                "minor",
+                "patch"
+              ],
+              "additionalProperties": false,
+              "description": "Semantic version of the protocol"
+            },
+            "specification": {
+              "type": "string",
+              "description": "URL or path to protocol specification"
+            },
+            "description": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "id",
+            "label",
+            "version"
+          ],
+          "additionalProperties": false
+        },
+        "conformance": {
+          "type": "string",
+          "enum": [
+            "full",
+            "partial",
+            "experimental",
+            "deprecated"
+          ],
+          "description": "Level of protocol conformance",
+          "default": "full"
+        },
+        "implementedFeatures": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "description": "List of implemented feature names"
+        },
+        "features": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "name": {
+                "type": "string",
+                "description": "Feature identifier within the protocol"
+              },
+              "enabled": {
+                "type": "boolean",
+                "default": true
+              },
+              "description": {
+                "type": "string"
+              },
+              "sinceVersion": {
+                "type": "string",
+                "description": "Version when this feature was added"
+              },
+              "deprecatedSince": {
+                "type": "string",
+                "description": "Version when deprecated"
+              }
+            },
+            "required": [
+              "name"
+            ],
+            "additionalProperties": false
+          }
+        },
+        "metadata": {
+          "type": "object",
+          "additionalProperties": {}
+        },
+        "certified": {
+          "type": "boolean",
+          "default": false,
+          "description": "Has passed official conformance tests"
+        },
+        "certificationDate": {
+          "type": "string",
+          "format": "date-time"
+        }
+      },
+      "required": [
+        "protocol"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/PluginCapabilityManifest.json b/packages/spec/json-schema/system/PluginCapabilityManifest.json
new file mode 100644
index 000000000..fa05a19e7
--- /dev/null
+++ b/packages/spec/json-schema/system/PluginCapabilityManifest.json
@@ -0,0 +1,410 @@
+{
+  "$ref": "#/definitions/PluginCapabilityManifest",
+  "definitions": {
+    "PluginCapabilityManifest": {
+      "type": "object",
+      "properties": {
+        "implements": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "protocol": {
+                "type": "object",
+                "properties": {
+                  "id": {
+                    "type": "string",
+                    "pattern": "^([a-z][a-z0-9]*\\.)+protocol\\.[a-z][a-z0-9._]*\\.v\\d+$",
+                    "description": "Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1)"
+                  },
+                  "label": {
+                    "type": "string"
+                  },
+                  "version": {
+                    "type": "object",
+                    "properties": {
+                      "major": {
+                        "type": "integer",
+                        "minimum": 0
+                      },
+                      "minor": {
+                        "type": "integer",
+                        "minimum": 0
+                      },
+                      "patch": {
+                        "type": "integer",
+                        "minimum": 0
+                      }
+                    },
+                    "required": [
+                      "major",
+                      "minor",
+                      "patch"
+                    ],
+                    "additionalProperties": false,
+                    "description": "Semantic version of the protocol"
+                  },
+                  "specification": {
+                    "type": "string",
+                    "description": "URL or path to protocol specification"
+                  },
+                  "description": {
+                    "type": "string"
+                  }
+                },
+                "required": [
+                  "id",
+                  "label",
+                  "version"
+                ],
+                "additionalProperties": false
+              },
+              "conformance": {
+                "type": "string",
+                "enum": [
+                  "full",
+                  "partial",
+                  "experimental",
+                  "deprecated"
+                ],
+                "description": "Level of protocol conformance",
+                "default": "full"
+              },
+              "implementedFeatures": {
+                "type": "array",
+                "items": {
+                  "type": "string"
+                },
+                "description": "List of implemented feature names"
+              },
+              "features": {
+                "type": "array",
+                "items": {
+                  "type": "object",
+                  "properties": {
+                    "name": {
+                      "type": "string",
+                      "description": "Feature identifier within the protocol"
+                    },
+                    "enabled": {
+                      "type": "boolean",
+                      "default": true
+                    },
+                    "description": {
+                      "type": "string"
+                    },
+                    "sinceVersion": {
+                      "type": "string",
+                      "description": "Version when this feature was added"
+                    },
+                    "deprecatedSince": {
+                      "type": "string",
+                      "description": "Version when deprecated"
+                    }
+                  },
+                  "required": [
+                    "name"
+                  ],
+                  "additionalProperties": false
+                }
+              },
+              "metadata": {
+                "type": "object",
+                "additionalProperties": {}
+              },
+              "certified": {
+                "type": "boolean",
+                "default": false,
+                "description": "Has passed official conformance tests"
+              },
+              "certificationDate": {
+                "type": "string",
+                "format": "date-time"
+              }
+            },
+            "required": [
+              "protocol"
+            ],
+            "additionalProperties": false
+          },
+          "description": "List of protocols this plugin conforms to"
+        },
+        "provides": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "id": {
+                "type": "string",
+                "pattern": "^([a-z][a-z0-9]*\\.)+interface\\.[a-z][a-z0-9._]+$",
+                "description": "Unique interface identifier"
+              },
+              "name": {
+                "type": "string"
+              },
+              "description": {
+                "type": "string"
+              },
+              "version": {
+                "type": "object",
+                "properties": {
+                  "major": {
+                    "type": "integer",
+                    "minimum": 0
+                  },
+                  "minor": {
+                    "type": "integer",
+                    "minimum": 0
+                  },
+                  "patch": {
+                    "type": "integer",
+                    "minimum": 0
+                  }
+                },
+                "required": [
+                  "major",
+                  "minor",
+                  "patch"
+                ],
+                "additionalProperties": false,
+                "description": "Semantic version of the protocol"
+              },
+              "methods": {
+                "type": "array",
+                "items": {
+                  "type": "object",
+                  "properties": {
+                    "name": {
+                      "type": "string",
+                      "description": "Method name"
+                    },
+                    "description": {
+                      "type": "string"
+                    },
+                    "parameters": {
+                      "type": "array",
+                      "items": {
+                        "type": "object",
+                        "properties": {
+                          "name": {
+                            "type": "string"
+                          },
+                          "type": {
+                            "type": "string",
+                            "description": "Type notation (e.g., string, number, User)"
+                          },
+                          "required": {
+                            "type": "boolean",
+                            "default": true
+                          },
+                          "description": {
+                            "type": "string"
+                          }
+                        },
+                        "required": [
+                          "name",
+                          "type"
+                        ],
+                        "additionalProperties": false
+                      }
+                    },
+                    "returnType": {
+                      "type": "string",
+                      "description": "Return value type"
+                    },
+                    "async": {
+                      "type": "boolean",
+                      "default": false,
+                      "description": "Whether method returns a Promise"
+                    }
+                  },
+                  "required": [
+                    "name"
+                  ],
+                  "additionalProperties": false
+                }
+              },
+              "events": {
+                "type": "array",
+                "items": {
+                  "type": "object",
+                  "properties": {
+                    "name": {
+                      "type": "string",
+                      "description": "Event name"
+                    },
+                    "description": {
+                      "type": "string"
+                    },
+                    "payload": {
+                      "type": "string",
+                      "description": "Event payload type"
+                    }
+                  },
+                  "required": [
+                    "name"
+                  ],
+                  "additionalProperties": false
+                }
+              },
+              "stability": {
+                "type": "string",
+                "enum": [
+                  "stable",
+                  "beta",
+                  "alpha",
+                  "experimental"
+                ],
+                "default": "stable"
+              }
+            },
+            "required": [
+              "id",
+              "name",
+              "version",
+              "methods"
+            ],
+            "additionalProperties": false
+          },
+          "description": "Services/APIs this plugin offers to others"
+        },
+        "requires": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "pluginId": {
+                "type": "string",
+                "pattern": "^([a-z][a-z0-9]*\\.)+[a-z][a-z0-9-]+$",
+                "description": "Required plugin identifier"
+              },
+              "version": {
+                "type": "string",
+                "description": "Semantic version constraint"
+              },
+              "optional": {
+                "type": "boolean",
+                "default": false
+              },
+              "reason": {
+                "type": "string"
+              },
+              "requiredCapabilities": {
+                "type": "array",
+                "items": {
+                  "type": "string"
+                },
+                "description": "Protocol IDs the dependency must support"
+              }
+            },
+            "required": [
+              "pluginId",
+              "version"
+            ],
+            "additionalProperties": false
+          },
+          "description": "Required plugins and their capabilities"
+        },
+        "extensionPoints": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "id": {
+                "type": "string",
+                "pattern": "^([a-z][a-z0-9]*\\.)+extension\\.[a-z][a-z0-9._]+$",
+                "description": "Unique extension point identifier"
+              },
+              "name": {
+                "type": "string"
+              },
+              "description": {
+                "type": "string"
+              },
+              "type": {
+                "type": "string",
+                "enum": [
+                  "action",
+                  "hook",
+                  "widget",
+                  "provider",
+                  "transformer",
+                  "validator",
+                  "decorator"
+                ]
+              },
+              "contract": {
+                "type": "object",
+                "properties": {
+                  "input": {
+                    "type": "string",
+                    "description": "Input type/schema"
+                  },
+                  "output": {
+                    "type": "string",
+                    "description": "Output type/schema"
+                  },
+                  "signature": {
+                    "type": "string",
+                    "description": "Function signature if applicable"
+                  }
+                },
+                "additionalProperties": false
+              },
+              "cardinality": {
+                "type": "string",
+                "enum": [
+                  "single",
+                  "multiple"
+                ],
+                "default": "multiple",
+                "description": "Whether multiple extensions can register to this point"
+              }
+            },
+            "required": [
+              "id",
+              "name",
+              "type"
+            ],
+            "additionalProperties": false
+          },
+          "description": "Points where other plugins can extend this plugin"
+        },
+        "extensions": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "targetPluginId": {
+                "type": "string",
+                "description": "Plugin ID being extended"
+              },
+              "extensionPointId": {
+                "type": "string",
+                "description": "Extension point identifier"
+              },
+              "implementation": {
+                "type": "string",
+                "description": "Path to implementation module"
+              },
+              "priority": {
+                "type": "integer",
+                "default": 100,
+                "description": "Registration priority (lower = higher priority)"
+              }
+            },
+            "required": [
+              "targetPluginId",
+              "extensionPointId",
+              "implementation"
+            ],
+            "additionalProperties": false
+          },
+          "description": "Extensions contributed to other plugins"
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/PluginDependency.json b/packages/spec/json-schema/system/PluginDependency.json
new file mode 100644
index 000000000..0daf3a3f1
--- /dev/null
+++ b/packages/spec/json-schema/system/PluginDependency.json
@@ -0,0 +1,39 @@
+{
+  "$ref": "#/definitions/PluginDependency",
+  "definitions": {
+    "PluginDependency": {
+      "type": "object",
+      "properties": {
+        "pluginId": {
+          "type": "string",
+          "pattern": "^([a-z][a-z0-9]*\\.)+[a-z][a-z0-9-]+$",
+          "description": "Required plugin identifier"
+        },
+        "version": {
+          "type": "string",
+          "description": "Semantic version constraint"
+        },
+        "optional": {
+          "type": "boolean",
+          "default": false
+        },
+        "reason": {
+          "type": "string"
+        },
+        "requiredCapabilities": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "description": "Protocol IDs the dependency must support"
+        }
+      },
+      "required": [
+        "pluginId",
+        "version"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/PluginInterface.json b/packages/spec/json-schema/system/PluginInterface.json
new file mode 100644
index 000000000..397bcd9ee
--- /dev/null
+++ b/packages/spec/json-schema/system/PluginInterface.json
@@ -0,0 +1,141 @@
+{
+  "$ref": "#/definitions/PluginInterface",
+  "definitions": {
+    "PluginInterface": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "type": "string",
+          "pattern": "^([a-z][a-z0-9]*\\.)+interface\\.[a-z][a-z0-9._]+$",
+          "description": "Unique interface identifier"
+        },
+        "name": {
+          "type": "string"
+        },
+        "description": {
+          "type": "string"
+        },
+        "version": {
+          "type": "object",
+          "properties": {
+            "major": {
+              "type": "integer",
+              "minimum": 0
+            },
+            "minor": {
+              "type": "integer",
+              "minimum": 0
+            },
+            "patch": {
+              "type": "integer",
+              "minimum": 0
+            }
+          },
+          "required": [
+            "major",
+            "minor",
+            "patch"
+          ],
+          "additionalProperties": false,
+          "description": "Semantic version of the protocol"
+        },
+        "methods": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "name": {
+                "type": "string",
+                "description": "Method name"
+              },
+              "description": {
+                "type": "string"
+              },
+              "parameters": {
+                "type": "array",
+                "items": {
+                  "type": "object",
+                  "properties": {
+                    "name": {
+                      "type": "string"
+                    },
+                    "type": {
+                      "type": "string",
+                      "description": "Type notation (e.g., string, number, User)"
+                    },
+                    "required": {
+                      "type": "boolean",
+                      "default": true
+                    },
+                    "description": {
+                      "type": "string"
+                    }
+                  },
+                  "required": [
+                    "name",
+                    "type"
+                  ],
+                  "additionalProperties": false
+                }
+              },
+              "returnType": {
+                "type": "string",
+                "description": "Return value type"
+              },
+              "async": {
+                "type": "boolean",
+                "default": false,
+                "description": "Whether method returns a Promise"
+              }
+            },
+            "required": [
+              "name"
+            ],
+            "additionalProperties": false
+          }
+        },
+        "events": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "name": {
+                "type": "string",
+                "description": "Event name"
+              },
+              "description": {
+                "type": "string"
+              },
+              "payload": {
+                "type": "string",
+                "description": "Event payload type"
+              }
+            },
+            "required": [
+              "name"
+            ],
+            "additionalProperties": false
+          }
+        },
+        "stability": {
+          "type": "string",
+          "enum": [
+            "stable",
+            "beta",
+            "alpha",
+            "experimental"
+          ],
+          "default": "stable"
+        }
+      },
+      "required": [
+        "id",
+        "name",
+        "version",
+        "methods"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/ProtocolFeature.json b/packages/spec/json-schema/system/ProtocolFeature.json
new file mode 100644
index 000000000..7f38fba4b
--- /dev/null
+++ b/packages/spec/json-schema/system/ProtocolFeature.json
@@ -0,0 +1,34 @@
+{
+  "$ref": "#/definitions/ProtocolFeature",
+  "definitions": {
+    "ProtocolFeature": {
+      "type": "object",
+      "properties": {
+        "name": {
+          "type": "string",
+          "description": "Feature identifier within the protocol"
+        },
+        "enabled": {
+          "type": "boolean",
+          "default": true
+        },
+        "description": {
+          "type": "string"
+        },
+        "sinceVersion": {
+          "type": "string",
+          "description": "Version when this feature was added"
+        },
+        "deprecatedSince": {
+          "type": "string",
+          "description": "Version when deprecated"
+        }
+      },
+      "required": [
+        "name"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/ProtocolReference.json b/packages/spec/json-schema/system/ProtocolReference.json
new file mode 100644
index 000000000..f47c51479
--- /dev/null
+++ b/packages/spec/json-schema/system/ProtocolReference.json
@@ -0,0 +1,56 @@
+{
+  "$ref": "#/definitions/ProtocolReference",
+  "definitions": {
+    "ProtocolReference": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "type": "string",
+          "pattern": "^([a-z][a-z0-9]*\\.)+protocol\\.[a-z][a-z0-9._]*\\.v\\d+$",
+          "description": "Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1)"
+        },
+        "label": {
+          "type": "string"
+        },
+        "version": {
+          "type": "object",
+          "properties": {
+            "major": {
+              "type": "integer",
+              "minimum": 0
+            },
+            "minor": {
+              "type": "integer",
+              "minimum": 0
+            },
+            "patch": {
+              "type": "integer",
+              "minimum": 0
+            }
+          },
+          "required": [
+            "major",
+            "minor",
+            "patch"
+          ],
+          "additionalProperties": false,
+          "description": "Semantic version of the protocol"
+        },
+        "specification": {
+          "type": "string",
+          "description": "URL or path to protocol specification"
+        },
+        "description": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "id",
+        "label",
+        "version"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/json-schema/system/ProtocolVersion.json b/packages/spec/json-schema/system/ProtocolVersion.json
new file mode 100644
index 000000000..811ba3254
--- /dev/null
+++ b/packages/spec/json-schema/system/ProtocolVersion.json
@@ -0,0 +1,30 @@
+{
+  "$ref": "#/definitions/ProtocolVersion",
+  "definitions": {
+    "ProtocolVersion": {
+      "type": "object",
+      "properties": {
+        "major": {
+          "type": "integer",
+          "minimum": 0
+        },
+        "minor": {
+          "type": "integer",
+          "minimum": 0
+        },
+        "patch": {
+          "type": "integer",
+          "minimum": 0
+        }
+      },
+      "required": [
+        "major",
+        "minor",
+        "patch"
+      ],
+      "additionalProperties": false,
+      "description": "Semantic version of the protocol"
+    }
+  },
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}
\ No newline at end of file
diff --git a/packages/spec/src/hub/index.ts b/packages/spec/src/hub/index.ts
index 8e09f8dfc..a4265ff8f 100644
--- a/packages/spec/src/hub/index.ts
+++ b/packages/spec/src/hub/index.ts
@@ -1,6 +1,7 @@
 // Export Hub Components
 export * from './composer.zod';
 export * from './marketplace.zod';
+export * from './plugin-registry.zod';
 export * from './space.zod';
 export * from './tenant.zod';
 export * from './license.zod';
diff --git a/packages/spec/src/hub/plugin-registry.zod.ts b/packages/spec/src/hub/plugin-registry.zod.ts
new file mode 100644
index 000000000..db72242ec
--- /dev/null
+++ b/packages/spec/src/hub/plugin-registry.zod.ts
@@ -0,0 +1,412 @@
+import { z } from 'zod';
+import { PluginCapabilityManifestSchema } from '../system/plugin-capability.zod';
+
+/**
+ * # Plugin Registry Protocol
+ * 
+ * Defines the schema for the plugin discovery and registry system.
+ * This enables plugins from different vendors to be discovered, validated,
+ * and composed together in the ObjectStack ecosystem.
+ */
+
+/**
+ * Plugin Vendor Information
+ */
+export const PluginVendorSchema = z.object({
+  /**
+   * Vendor identifier (reverse domain notation)
+   * Example: "com.acme", "org.apache", "com.objectstack"
+   */
+  id: z.string()
+    .regex(/^[a-z][a-z0-9]*(\.[a-z][a-z0-9]*)+$/)
+    .describe('Vendor identifier (reverse domain)'),
+  
+  /**
+   * Vendor display name
+   */
+  name: z.string(),
+  
+  /**
+   * Vendor website
+   */
+  website: z.string().url().optional(),
+  
+  /**
+   * Contact email
+   */
+  email: z.string().email().optional(),
+  
+  /**
+   * Verification status
+   */
+  verified: z.boolean().default(false).describe('Whether vendor is verified by ObjectStack'),
+  
+  /**
+   * Trust level
+   */
+  trustLevel: z.enum(['official', 'verified', 'community', 'unverified']).default('unverified'),
+});
+
+/**
+ * Plugin Quality Metrics
+ */
+export const PluginQualityMetricsSchema = z.object({
+  /**
+   * Test coverage percentage
+   */
+  testCoverage: z.number().min(0).max(100).optional(),
+  
+  /**
+   * Documentation score (0-100)
+   */
+  documentationScore: z.number().min(0).max(100).optional(),
+  
+  /**
+   * Code quality score (0-100)
+   */
+  codeQuality: z.number().min(0).max(100).optional(),
+  
+  /**
+   * Security scan status
+   */
+  securityScan: z.object({
+    lastScanDate: z.string().datetime().optional(),
+    vulnerabilities: z.object({
+      critical: z.number().int().min(0).default(0),
+      high: z.number().int().min(0).default(0),
+      medium: z.number().int().min(0).default(0),
+      low: z.number().int().min(0).default(0),
+    }).optional(),
+    passed: z.boolean().default(false),
+  }).optional(),
+  
+  /**
+   * Conformance test results
+   */
+  conformanceTests: z.array(z.object({
+    protocolId: z.string().describe('Protocol being tested'),
+    passed: z.boolean(),
+    totalTests: z.number().int().min(0),
+    passedTests: z.number().int().min(0),
+    lastRunDate: z.string().datetime().optional(),
+  })).optional(),
+});
+
+/**
+ * Plugin Usage Statistics
+ */
+export const PluginStatisticsSchema = z.object({
+  /**
+   * Total downloads
+   */
+  downloads: z.number().int().min(0).default(0),
+  
+  /**
+   * Downloads in the last 30 days
+   */
+  downloadsLastMonth: z.number().int().min(0).default(0),
+  
+  /**
+   * Number of active installations
+   */
+  activeInstallations: z.number().int().min(0).default(0),
+  
+  /**
+   * User ratings
+   */
+  ratings: z.object({
+    average: z.number().min(0).max(5).default(0),
+    count: z.number().int().min(0).default(0),
+    distribution: z.object({
+      '5': z.number().int().min(0).default(0),
+      '4': z.number().int().min(0).default(0),
+      '3': z.number().int().min(0).default(0),
+      '2': z.number().int().min(0).default(0),
+      '1': z.number().int().min(0).default(0),
+    }).optional(),
+  }).optional(),
+  
+  /**
+   * GitHub stars (if open source)
+   */
+  stars: z.number().int().min(0).optional(),
+  
+  /**
+   * Number of dependent plugins
+   */
+  dependents: z.number().int().min(0).default(0),
+});
+
+/**
+ * Plugin Registry Entry
+ * Complete metadata for a plugin in the registry.
+ */
+export const PluginRegistryEntrySchema = z.object({
+  /**
+   * Plugin identifier (must match manifest.id)
+   */
+  id: z.string()
+    .regex(/^([a-z][a-z0-9]*\.)+[a-z][a-z0-9-]+$/)
+    .describe('Plugin identifier (reverse domain notation)'),
+  
+  /**
+   * Current version
+   */
+  version: z.string().regex(/^\d+\.\d+\.\d+$/),
+  
+  /**
+   * Plugin display name
+   */
+  name: z.string(),
+  
+  /**
+   * Short description
+   */
+  description: z.string().optional(),
+  
+  /**
+   * Detailed documentation/README
+   */
+  readme: z.string().optional(),
+  
+  /**
+   * Plugin type/category
+   */
+  category: z.enum([
+    'data',           // Data management, storage, databases
+    'integration',    // External service integrations
+    'ui',            // UI components and themes
+    'analytics',     // Analytics and reporting
+    'security',      // Security, auth, compliance
+    'automation',    // Workflows and automation
+    'ai',            // AI/ML capabilities
+    'utility',       // General utilities
+    'driver',        // Database/storage drivers
+    'gateway',       // API gateways
+    'adapter',       // Runtime adapters
+  ]).optional(),
+  
+  /**
+   * Tags for categorization
+   */
+  tags: z.array(z.string()).optional(),
+  
+  /**
+   * Vendor information
+   */
+  vendor: PluginVendorSchema,
+  
+  /**
+   * Capability manifest (what the plugin implements/provides)
+   */
+  capabilities: PluginCapabilityManifestSchema.optional(),
+  
+  /**
+   * Compatibility information
+   */
+  compatibility: z.object({
+    /**
+     * Minimum ObjectStack version required
+     */
+    minObjectStackVersion: z.string().optional(),
+    
+    /**
+     * Maximum ObjectStack version supported
+     */
+    maxObjectStackVersion: z.string().optional(),
+    
+    /**
+     * Node.js version requirement
+     */
+    nodeVersion: z.string().optional(),
+    
+    /**
+     * Supported platforms
+     */
+    platforms: z.array(z.enum(['linux', 'darwin', 'win32', 'browser'])).optional(),
+  }).optional(),
+  
+  /**
+   * Links and resources
+   */
+  links: z.object({
+    homepage: z.string().url().optional(),
+    repository: z.string().url().optional(),
+    documentation: z.string().url().optional(),
+    bugs: z.string().url().optional(),
+    changelog: z.string().url().optional(),
+  }).optional(),
+  
+  /**
+   * Media assets
+   */
+  media: z.object({
+    icon: z.string().url().optional(),
+    logo: z.string().url().optional(),
+    screenshots: z.array(z.string().url()).optional(),
+    video: z.string().url().optional(),
+  }).optional(),
+  
+  /**
+   * Quality metrics
+   */
+  quality: PluginQualityMetricsSchema.optional(),
+  
+  /**
+   * Usage statistics
+   */
+  statistics: PluginStatisticsSchema.optional(),
+  
+  /**
+   * License information
+   */
+  license: z.string().optional().describe('SPDX license identifier'),
+  
+  /**
+   * Pricing (if commercial)
+   */
+  pricing: z.object({
+    model: z.enum(['free', 'freemium', 'paid', 'enterprise']),
+    price: z.number().min(0).optional(),
+    currency: z.string().default('USD').optional(),
+    billingPeriod: z.enum(['one-time', 'monthly', 'yearly']).optional(),
+  }).optional(),
+  
+  /**
+   * Publication dates
+   */
+  publishedAt: z.string().datetime().optional(),
+  updatedAt: z.string().datetime().optional(),
+  
+  /**
+   * Deprecation status
+   */
+  deprecated: z.boolean().default(false),
+  deprecationMessage: z.string().optional(),
+  replacedBy: z.string().optional().describe('Plugin ID that replaces this one'),
+  
+  /**
+   * Feature flags
+   */
+  flags: z.object({
+    experimental: z.boolean().default(false),
+    beta: z.boolean().default(false),
+    featured: z.boolean().default(false),
+    verified: z.boolean().default(false),
+  }).optional(),
+});
+
+/**
+ * Plugin Search Filters
+ */
+export const PluginSearchFiltersSchema = z.object({
+  /**
+   * Search query
+   */
+  query: z.string().optional(),
+  
+  /**
+   * Filter by category
+   */
+  category: z.array(z.string()).optional(),
+  
+  /**
+   * Filter by tags
+   */
+  tags: z.array(z.string()).optional(),
+  
+  /**
+   * Filter by vendor trust level
+   */
+  trustLevel: z.array(z.enum(['official', 'verified', 'community', 'unverified'])).optional(),
+  
+  /**
+   * Filter by protocols implemented
+   */
+  implementsProtocols: z.array(z.string()).optional(),
+  
+  /**
+   * Filter by pricing model
+   */
+  pricingModel: z.array(z.enum(['free', 'freemium', 'paid', 'enterprise'])).optional(),
+  
+  /**
+   * Minimum rating
+   */
+  minRating: z.number().min(0).max(5).optional(),
+  
+  /**
+   * Sort options
+   */
+  sortBy: z.enum([
+    'relevance',
+    'downloads',
+    'rating',
+    'updated',
+    'name',
+  ]).optional(),
+  
+  /**
+   * Sort order
+   */
+  sortOrder: z.enum(['asc', 'desc']).default('desc').optional(),
+  
+  /**
+   * Pagination
+   */
+  page: z.number().int().min(1).default(1).optional(),
+  limit: z.number().int().min(1).max(100).default(20).optional(),
+});
+
+/**
+ * Plugin Installation Configuration
+ */
+export const PluginInstallConfigSchema = z.object({
+  /**
+   * Plugin identifier to install
+   */
+  pluginId: z.string(),
+  
+  /**
+   * Version to install (supports semver ranges)
+   */
+  version: z.string().optional().describe('Defaults to latest'),
+  
+  /**
+   * Plugin-specific configuration values
+   */
+  config: z.record(z.any()).optional(),
+  
+  /**
+   * Whether to auto-update
+   */
+  autoUpdate: z.boolean().default(false).optional(),
+  
+  /**
+   * Installation options
+   */
+  options: z.object({
+    /**
+     * Skip dependency installation
+     */
+    skipDependencies: z.boolean().default(false).optional(),
+    
+    /**
+     * Force reinstall
+     */
+    force: z.boolean().default(false).optional(),
+    
+    /**
+     * Installation target
+     */
+    target: z.enum(['system', 'space', 'user']).default('space').optional(),
+  }).optional(),
+});
+
+// Export types
+export type PluginVendor = z.infer<typeof PluginVendorSchema>;
+export type PluginQualityMetrics = z.infer<typeof PluginQualityMetricsSchema>;
+export type PluginStatistics = z.infer<typeof PluginStatisticsSchema>;
+export type PluginRegistryEntry = z.infer<typeof PluginRegistryEntrySchema>;
+export type PluginSearchFilters = z.infer<typeof PluginSearchFiltersSchema>;
+export type PluginInstallConfig = z.infer<typeof PluginInstallConfigSchema>;
diff --git a/packages/spec/src/system/index.ts b/packages/spec/src/system/index.ts
index f441582fb..d3298d978 100644
--- a/packages/spec/src/system/index.ts
+++ b/packages/spec/src/system/index.ts
@@ -17,6 +17,7 @@ export * from './types';
 // Re-export Core System Definitions
 export * from './manifest.zod';
 export * from './plugin.zod';
+export * from './plugin-capability.zod';
 export * from './logger.zod';
 export * from './context.zod';
 export * from './scoped-storage.zod';
diff --git a/packages/spec/src/system/manifest.zod.ts b/packages/spec/src/system/manifest.zod.ts
index c8030a61d..5139dc5bc 100644
--- a/packages/spec/src/system/manifest.zod.ts
+++ b/packages/spec/src/system/manifest.zod.ts
@@ -1,4 +1,5 @@
 import { z } from 'zod';
+import { PluginCapabilityManifestSchema } from './plugin-capability.zod';
 
 /**
  * Schema for the ObjectStack Manifest.
@@ -183,6 +184,14 @@ export const ManifestSchema = z.object({
     mode: z.enum(['upsert', 'insert', 'ignore']).default('upsert').describe('Seeding mode')
   })).optional().describe('Initial seed data'),
 
+  /**
+   * Plugin Capability Manifest.
+   * Declares protocols implemented, interfaces provided, dependencies, and extension points.
+   * This enables plugin interoperability and automatic discovery.
+   */
+  capabilities: PluginCapabilityManifestSchema.optional()
+    .describe('Plugin capability declarations for interoperability'),
+
   /** 
    * Extension points contributed by this package.
    * Allows packages to extend UI components, add functionality, etc.
diff --git a/packages/spec/src/system/plugin-capability.test.ts b/packages/spec/src/system/plugin-capability.test.ts
new file mode 100644
index 000000000..1c3d279e9
--- /dev/null
+++ b/packages/spec/src/system/plugin-capability.test.ts
@@ -0,0 +1,330 @@
+import { describe, it, expect } from 'vitest';
+import {
+  CapabilityConformanceLevelSchema,
+  ProtocolVersionSchema,
+  ProtocolReferenceSchema,
+  PluginCapabilitySchema,
+  PluginInterfaceSchema,
+  PluginDependencySchema,
+  ExtensionPointSchema,
+  PluginCapabilityManifestSchema,
+  ProtocolFeatureSchema,
+} from './plugin-capability.zod';
+
+describe('Plugin Capability Schemas', () => {
+  describe('CapabilityConformanceLevelSchema', () => {
+    it('should accept valid conformance levels', () => {
+      expect(CapabilityConformanceLevelSchema.parse('full')).toBe('full');
+      expect(CapabilityConformanceLevelSchema.parse('partial')).toBe('partial');
+      expect(CapabilityConformanceLevelSchema.parse('experimental')).toBe('experimental');
+      expect(CapabilityConformanceLevelSchema.parse('deprecated')).toBe('deprecated');
+    });
+
+    it('should reject invalid conformance levels', () => {
+      expect(() => CapabilityConformanceLevelSchema.parse('invalid')).toThrow();
+    });
+  });
+
+  describe('ProtocolVersionSchema', () => {
+    it('should accept valid semantic versions', () => {
+      const version = ProtocolVersionSchema.parse({ major: 1, minor: 2, patch: 3 });
+      expect(version).toEqual({ major: 1, minor: 2, patch: 3 });
+    });
+
+    it('should reject negative version numbers', () => {
+      expect(() => ProtocolVersionSchema.parse({ major: -1, minor: 0, patch: 0 })).toThrow();
+    });
+
+    it('should reject non-integer versions', () => {
+      expect(() => ProtocolVersionSchema.parse({ major: 1.5, minor: 0, patch: 0 })).toThrow();
+    });
+  });
+
+  describe('ProtocolReferenceSchema', () => {
+    it('should accept valid protocol identifiers', () => {
+      const protocol = ProtocolReferenceSchema.parse({
+        id: 'com.objectstack.protocol.storage.v1',
+        label: 'Storage Protocol',
+        version: { major: 1, minor: 0, patch: 0 },
+      });
+      expect(protocol.id).toBe('com.objectstack.protocol.storage.v1');
+    });
+
+    it('should accept protocol with subcategories', () => {
+      const protocol = ProtocolReferenceSchema.parse({
+        id: 'com.objectstack.protocol.auth.oauth2.v2',
+        label: 'OAuth2 Authentication Protocol',
+        version: { major: 2, minor: 0, patch: 0 },
+      });
+      expect(protocol.id).toBe('com.objectstack.protocol.auth.oauth2.v2');
+    });
+
+    it('should reject invalid protocol format', () => {
+      expect(() => ProtocolReferenceSchema.parse({
+        id: 'invalid-protocol',
+        label: 'Invalid',
+        version: { major: 1, minor: 0, patch: 0 },
+      })).toThrow();
+    });
+
+    it('should reject protocol without version suffix', () => {
+      expect(() => ProtocolReferenceSchema.parse({
+        id: 'com.objectstack.protocol.storage',
+        label: 'Storage',
+        version: { major: 1, minor: 0, patch: 0 },
+      })).toThrow();
+    });
+  });
+
+  describe('ProtocolFeatureSchema', () => {
+    it('should accept minimal feature flag', () => {
+      const feature = ProtocolFeatureSchema.parse({
+        name: 'advanced_caching',
+      });
+      expect(feature.name).toBe('advanced_caching');
+      expect(feature.enabled).toBe(true);
+    });
+
+    it('should accept feature with deprecation info', () => {
+      const feature = ProtocolFeatureSchema.parse({
+        name: 'legacy_api',
+        enabled: false,
+        deprecatedSince: '2.0.0',
+      });
+      expect(feature.deprecatedSince).toBe('2.0.0');
+    });
+  });
+
+  describe('PluginCapabilitySchema', () => {
+    it('should accept full conformance capability', () => {
+      const capability = PluginCapabilitySchema.parse({
+        protocol: {
+          id: 'com.objectstack.protocol.storage.v1',
+          label: 'Storage Protocol',
+          version: { major: 1, minor: 0, patch: 0 },
+        },
+        conformance: 'full',
+        certified: true,
+      });
+      expect(capability.conformance).toBe('full');
+    });
+
+    it('should accept partial conformance with features', () => {
+      const capability = PluginCapabilitySchema.parse({
+        protocol: {
+          id: 'com.objectstack.protocol.storage.v1',
+          label: 'Storage Protocol',
+          version: { major: 1, minor: 0, patch: 0 },
+        },
+        conformance: 'partial',
+        implementedFeatures: ['read', 'write', 'delete'],
+      });
+      expect(capability.implementedFeatures).toHaveLength(3);
+    });
+
+    it('should default to full conformance', () => {
+      const capability = PluginCapabilitySchema.parse({
+        protocol: {
+          id: 'com.objectstack.protocol.storage.v1',
+          label: 'Storage Protocol',
+          version: { major: 1, minor: 0, patch: 0 },
+        },
+      });
+      expect(capability.conformance).toBe('full');
+    });
+  });
+
+  describe('PluginInterfaceSchema', () => {
+    it('should accept valid interface declaration', () => {
+      const iface = PluginInterfaceSchema.parse({
+        id: 'com.acme.crm.interface.contact_service',
+        name: 'ContactService',
+        version: { major: 1, minor: 0, patch: 0 },
+        methods: [
+          {
+            name: 'getContact',
+            description: 'Retrieve a contact by ID',
+            parameters: [
+              { name: 'id', type: 'string', required: true },
+            ],
+            returnType: 'Contact',
+            async: true,
+          },
+        ],
+      });
+      expect(iface.methods).toHaveLength(1);
+      expect(iface.stability).toBe('stable');
+    });
+
+    it('should accept interface with events', () => {
+      const iface = PluginInterfaceSchema.parse({
+        id: 'com.acme.crm.interface.contact_service',
+        name: 'ContactService',
+        version: { major: 1, minor: 0, patch: 0 },
+        methods: [],
+        events: [
+          {
+            name: 'contactCreated',
+            description: 'Fired when a new contact is created',
+            payload: 'Contact',
+          },
+        ],
+      });
+      expect(iface.events).toHaveLength(1);
+    });
+
+    it('should reject invalid interface id format', () => {
+      expect(() => PluginInterfaceSchema.parse({
+        id: 'invalid_interface',
+        name: 'Invalid',
+        version: { major: 1, minor: 0, patch: 0 },
+        methods: [],
+      })).toThrow();
+    });
+  });
+
+  describe('PluginDependencySchema', () => {
+    it('should accept valid plugin dependency', () => {
+      const dep = PluginDependencySchema.parse({
+        pluginId: 'com.objectstack.driver.postgres',
+        version: '^1.0.0',
+      });
+      expect(dep.optional).toBe(false);
+    });
+
+    it('should accept optional dependency', () => {
+      const dep = PluginDependencySchema.parse({
+        pluginId: 'com.acme.analytics',
+        version: '>=2.0.0',
+        optional: true,
+        reason: 'Enhanced analytics features',
+      });
+      expect(dep.optional).toBe(true);
+    });
+
+    it('should accept dependency with capability requirements', () => {
+      const dep = PluginDependencySchema.parse({
+        pluginId: 'com.objectstack.driver.postgres',
+        version: '1.0.0',
+        requiredCapabilities: [
+          'com.objectstack.protocol.storage.v1',
+          'com.objectstack.protocol.transactions.v1',
+        ],
+      });
+      expect(dep.requiredCapabilities).toHaveLength(2);
+    });
+
+    it('should reject invalid plugin id', () => {
+      expect(() => PluginDependencySchema.parse({
+        pluginId: 'Invalid_Plugin',
+        version: '1.0.0',
+      })).toThrow();
+    });
+  });
+
+  describe('ExtensionPointSchema', () => {
+    it('should accept valid extension point', () => {
+      const ext = ExtensionPointSchema.parse({
+        id: 'com.acme.crm.extension.contact_validator',
+        name: 'Contact Validator',
+        type: 'validator',
+        contract: {
+          input: 'Contact',
+          output: 'ValidationResult',
+        },
+      });
+      expect(ext.type).toBe('validator');
+      expect(ext.cardinality).toBe('multiple');
+    });
+
+    it('should accept single cardinality extension point', () => {
+      const ext = ExtensionPointSchema.parse({
+        id: 'com.acme.app.extension.theme_provider',
+        name: 'Theme Provider',
+        type: 'provider',
+        cardinality: 'single',
+      });
+      expect(ext.cardinality).toBe('single');
+    });
+
+    it('should accept all extension types', () => {
+      const types = ['action', 'hook', 'widget', 'provider', 'transformer', 'validator', 'decorator'];
+      types.forEach(type => {
+        const ext = ExtensionPointSchema.parse({
+          id: `com.test.extension.${type}`,
+          name: type,
+          type,
+        });
+        expect(ext.type).toBe(type);
+      });
+    });
+  });
+
+  describe('PluginCapabilityManifestSchema', () => {
+    it('should accept complete capability manifest', () => {
+      const manifest = PluginCapabilityManifestSchema.parse({
+        implements: [
+          {
+            protocol: {
+              id: 'com.objectstack.protocol.storage.v1',
+              label: 'Storage Protocol',
+              version: { major: 1, minor: 0, patch: 0 },
+            },
+            conformance: 'full',
+          },
+        ],
+        provides: [
+          {
+            id: 'com.acme.crm.interface.contact_service',
+            name: 'ContactService',
+            version: { major: 1, minor: 0, patch: 0 },
+            methods: [
+              {
+                name: 'getContact',
+                returnType: 'Contact',
+                async: true,
+              },
+            ],
+          },
+        ],
+        requires: [
+          {
+            pluginId: 'com.objectstack.driver.postgres',
+            version: '^1.0.0',
+          },
+        ],
+        extensionPoints: [
+          {
+            id: 'com.acme.crm.extension.contact_validator',
+            name: 'Contact Validator',
+            type: 'validator',
+          },
+        ],
+      });
+      expect(manifest.implements).toHaveLength(1);
+      expect(manifest.provides).toHaveLength(1);
+      expect(manifest.requires).toHaveLength(1);
+      expect(manifest.extensionPoints).toHaveLength(1);
+    });
+
+    it('should accept manifest with extensions', () => {
+      const manifest = PluginCapabilityManifestSchema.parse({
+        extensions: [
+          {
+            targetPluginId: 'com.acme.crm',
+            extensionPointId: 'com.acme.crm.extension.contact_validator',
+            implementation: './validators/email-validator.ts',
+            priority: 50,
+          },
+        ],
+      });
+      expect(manifest.extensions).toHaveLength(1);
+      expect(manifest.extensions![0].priority).toBe(50);
+    });
+
+    it('should accept empty manifest', () => {
+      const manifest = PluginCapabilityManifestSchema.parse({});
+      expect(manifest).toBeDefined();
+    });
+  });
+});
diff --git a/packages/spec/src/system/plugin-capability.zod.ts b/packages/spec/src/system/plugin-capability.zod.ts
new file mode 100644
index 000000000..b50f4db70
--- /dev/null
+++ b/packages/spec/src/system/plugin-capability.zod.ts
@@ -0,0 +1,317 @@
+import { z } from 'zod';
+
+/**
+ * # Plugin Capability Protocol
+ * 
+ * Defines the standard way plugins declare their capabilities, implementations,
+ * and conformance levels to ensure interoperability across vendors.
+ * 
+ * Based on the Protocol-Oriented Architecture pattern similar to:
+ * - Kubernetes CRDs (Custom Resource Definitions)
+ * - OSGi Service Registry
+ * - Eclipse Extension Points
+ */
+
+/**
+ * Capability Conformance Level
+ * Indicates how completely a plugin implements a given protocol.
+ */
+export const CapabilityConformanceLevelSchema = z.enum([
+  'full',        // Complete implementation of all protocol features
+  'partial',     // Subset implementation with specific features listed
+  'experimental', // Unstable/preview implementation
+  'deprecated',  // Still supported but scheduled for removal
+]).describe('Level of protocol conformance');
+
+/**
+ * Protocol Version Schema
+ * Uses semantic versioning to track protocol evolution.
+ */
+export const ProtocolVersionSchema = z.object({
+  major: z.number().int().min(0),
+  minor: z.number().int().min(0),
+  patch: z.number().int().min(0),
+}).describe('Semantic version of the protocol');
+
+/**
+ * Protocol Reference
+ * Uniquely identifies a protocol/interface that a plugin can implement.
+ * 
+ * Examples:
+ * - com.objectstack.protocol.storage.v1
+ * - com.objectstack.protocol.auth.oauth2.v2
+ * - com.acme.protocol.payment.stripe.v1
+ */
+export const ProtocolReferenceSchema = z.object({
+  /**
+   * Protocol identifier using reverse domain notation.
+   * Format: {domain}.protocol.{category}.{name}[.{subcategory}].v{major}
+   */
+  id: z.string()
+    .regex(/^([a-z][a-z0-9]*\.)+protocol\.[a-z][a-z0-9._]*\.v\d+$/)
+    .describe('Unique protocol identifier (e.g., com.objectstack.protocol.storage.v1)'),
+  
+  /**
+   * Human-readable protocol name
+   */
+  label: z.string(),
+  
+  /**
+   * Protocol version
+   */
+  version: ProtocolVersionSchema,
+  
+  /**
+   * Detailed protocol specification URL or file reference
+   */
+  specification: z.string().optional().describe('URL or path to protocol specification'),
+  
+  /**
+   * Brief description of what this protocol defines
+   */
+  description: z.string().optional(),
+});
+
+/**
+ * Protocol Feature
+ * Represents a specific capability within a protocol.
+ */
+export const ProtocolFeatureSchema = z.object({
+  name: z.string().describe('Feature identifier within the protocol'),
+  enabled: z.boolean().default(true),
+  description: z.string().optional(),
+  sinceVersion: z.string().optional().describe('Version when this feature was added'),
+  deprecatedSince: z.string().optional().describe('Version when deprecated'),
+});
+
+/**
+ * Plugin Capability Declaration
+ * Documents what protocols a plugin implements and to what extent.
+ */
+export const PluginCapabilitySchema = z.object({
+  /**
+   * The protocol being implemented
+   */
+  protocol: ProtocolReferenceSchema,
+  
+  /**
+   * Conformance level
+   */
+  conformance: CapabilityConformanceLevelSchema.default('full'),
+  
+  /**
+   * Specific features implemented (required if conformance is 'partial')
+   */
+  implementedFeatures: z.array(z.string()).optional().describe('List of implemented feature names'),
+  
+  /**
+   * Optional feature flags indicating advanced capabilities
+   */
+  features: z.array(ProtocolFeatureSchema).optional(),
+  
+  /**
+   * Custom metadata for vendor-specific information
+   */
+  metadata: z.record(z.any()).optional(),
+  
+  /**
+   * Testing/Certification status
+   */
+  certified: z.boolean().default(false).describe('Has passed official conformance tests'),
+  certificationDate: z.string().datetime().optional(),
+});
+
+/**
+ * Plugin Interface Declaration
+ * Defines the contract for services this plugin provides to other plugins.
+ */
+export const PluginInterfaceSchema = z.object({
+  /**
+   * Unique interface identifier
+   * Format: {plugin-id}.interface.{name}
+   */
+  id: z.string()
+    .regex(/^([a-z][a-z0-9]*\.)+interface\.[a-z][a-z0-9._]+$/)
+    .describe('Unique interface identifier'),
+  
+  /**
+   * Interface name
+   */
+  name: z.string(),
+  
+  /**
+   * Description of what this interface provides
+   */
+  description: z.string().optional(),
+  
+  /**
+   * Interface version
+   */
+  version: ProtocolVersionSchema,
+  
+  /**
+   * Methods exposed by this interface
+   */
+  methods: z.array(z.object({
+    name: z.string().describe('Method name'),
+    description: z.string().optional(),
+    parameters: z.array(z.object({
+      name: z.string(),
+      type: z.string().describe('Type notation (e.g., string, number, User)'),
+      required: z.boolean().default(true),
+      description: z.string().optional(),
+    })).optional(),
+    returnType: z.string().optional().describe('Return value type'),
+    async: z.boolean().default(false).describe('Whether method returns a Promise'),
+  })),
+  
+  /**
+   * Events emitted by this interface
+   */
+  events: z.array(z.object({
+    name: z.string().describe('Event name'),
+    description: z.string().optional(),
+    payload: z.string().optional().describe('Event payload type'),
+  })).optional(),
+  
+  /**
+   * Stability level
+   */
+  stability: z.enum(['stable', 'beta', 'alpha', 'experimental']).default('stable'),
+});
+
+/**
+ * Plugin Dependency Declaration
+ * Specifies what other plugins or capabilities this plugin requires.
+ */
+export const PluginDependencySchema = z.object({
+  /**
+   * Plugin ID using reverse domain notation
+   */
+  pluginId: z.string()
+    .regex(/^([a-z][a-z0-9]*\.)+[a-z][a-z0-9-]+$/)
+    .describe('Required plugin identifier'),
+  
+  /**
+   * Version constraint (supports semver ranges)
+   * Examples: "1.0.0", "^1.2.3", ">=2.0.0 <3.0.0"
+   */
+  version: z.string().describe('Semantic version constraint'),
+  
+  /**
+   * Whether this dependency is optional
+   */
+  optional: z.boolean().default(false),
+  
+  /**
+   * Reason for the dependency
+   */
+  reason: z.string().optional(),
+  
+  /**
+   * Minimum required capabilities from the dependency
+   */
+  requiredCapabilities: z.array(z.string()).optional().describe('Protocol IDs the dependency must support'),
+});
+
+/**
+ * Extension Point Declaration
+ * Defines hooks where other plugins can extend this plugin's functionality.
+ */
+export const ExtensionPointSchema = z.object({
+  /**
+   * Extension point identifier
+   */
+  id: z.string()
+    .regex(/^([a-z][a-z0-9]*\.)+extension\.[a-z][a-z0-9._]+$/)
+    .describe('Unique extension point identifier'),
+  
+  /**
+   * Extension point name
+   */
+  name: z.string(),
+  
+  /**
+   * Description
+   */
+  description: z.string().optional(),
+  
+  /**
+   * Type of extension point
+   */
+  type: z.enum([
+    'action',          // Plugins can register executable actions
+    'hook',            // Plugins can listen to lifecycle events
+    'widget',          // Plugins can contribute UI widgets
+    'provider',        // Plugins can provide data/services
+    'transformer',     // Plugins can transform data
+    'validator',       // Plugins can validate data
+    'decorator',       // Plugins can enhance/wrap functionality
+  ]),
+  
+  /**
+   * Expected interface contract for extensions
+   */
+  contract: z.object({
+    input: z.string().optional().describe('Input type/schema'),
+    output: z.string().optional().describe('Output type/schema'),
+    signature: z.string().optional().describe('Function signature if applicable'),
+  }).optional(),
+  
+  /**
+   * Cardinality
+   */
+  cardinality: z.enum(['single', 'multiple']).default('multiple')
+    .describe('Whether multiple extensions can register to this point'),
+});
+
+/**
+ * Complete Plugin Capability Manifest
+ * This is included in the main plugin manifest to declare all capabilities.
+ */
+export const PluginCapabilityManifestSchema = z.object({
+  /**
+   * Protocols this plugin implements
+   */
+  implements: z.array(PluginCapabilitySchema).optional()
+    .describe('List of protocols this plugin conforms to'),
+  
+  /**
+   * Interfaces this plugin exposes to other plugins
+   */
+  provides: z.array(PluginInterfaceSchema).optional()
+    .describe('Services/APIs this plugin offers to others'),
+  
+  /**
+   * Dependencies on other plugins
+   */
+  requires: z.array(PluginDependencySchema).optional()
+    .describe('Required plugins and their capabilities'),
+  
+  /**
+   * Extension points this plugin defines
+   */
+  extensionPoints: z.array(ExtensionPointSchema).optional()
+    .describe('Points where other plugins can extend this plugin'),
+  
+  /**
+   * Extensions this plugin contributes to other plugins
+   */
+  extensions: z.array(z.object({
+    targetPluginId: z.string().describe('Plugin ID being extended'),
+    extensionPointId: z.string().describe('Extension point identifier'),
+    implementation: z.string().describe('Path to implementation module'),
+    priority: z.number().int().default(100).describe('Registration priority (lower = higher priority)'),
+  })).optional().describe('Extensions contributed to other plugins'),
+});
+
+// Export types
+export type CapabilityConformanceLevel = z.infer<typeof CapabilityConformanceLevelSchema>;
+export type ProtocolVersion = z.infer<typeof ProtocolVersionSchema>;
+export type ProtocolReference = z.infer<typeof ProtocolReferenceSchema>;
+export type ProtocolFeature = z.infer<typeof ProtocolFeatureSchema>;
+export type PluginCapability = z.infer<typeof PluginCapabilitySchema>;
+export type PluginInterface = z.infer<typeof PluginInterfaceSchema>;
+export type PluginDependency = z.infer<typeof PluginDependencySchema>;
+export type ExtensionPoint = z.infer<typeof ExtensionPointSchema>;
+export type PluginCapabilityManifest = z.infer<typeof PluginCapabilityManifestSchema>;