diff --git a/tests/integration/all-apis-comprehensive.test.ts b/tests/integration/all-apis-comprehensive.test.ts
index 5f793f37..d0390b56 100644
--- a/tests/integration/all-apis-comprehensive.test.ts
+++ b/tests/integration/all-apis-comprehensive.test.ts
@@ -224,7 +224,7 @@ describe('Comprehensive All-APIs Test', () => {
     let vfs: any
 
     it('vfs.init() - should initialize VFS', async () => {
-      vfs = brain.vfs()
+      vfs = brain.vfs
       await vfs.init()
 
       expect(vfs).toBeDefined()
diff --git a/tests/integration/entity-confidence-weight.test.ts b/tests/integration/entity-confidence-weight.test.ts
index f678389a..b902e589 100644
--- a/tests/integration/entity-confidence-weight.test.ts
+++ b/tests/integration/entity-confidence-weight.test.ts
@@ -308,7 +308,7 @@ describe('Entity Confidence & Weight Exposure', () => {
 
   describe('VFS integration', () => {
     it('should expose confidence/weight for VFS entities', async () => {
-      const vfs = brain.vfs()
+      const vfs = brain.vfs
       await vfs.init()
 
       await vfs.writeFile('/test.txt', 'VFS test content')
diff --git a/tests/integration/remaining-apis.test.ts b/tests/integration/remaining-apis.test.ts
index 5420c0d6..97637b3a 100644
--- a/tests/integration/remaining-apis.test.ts
+++ b/tests/integration/remaining-apis.test.ts
@@ -121,7 +121,7 @@ Carol,35,Manager`
       expect(result.stats.vfsFilesCreated).toBeGreaterThan(0)
 
       // Verify VFS file was created
-      const vfs = brain.vfs()
+      const vfs = brain.vfs
       await vfs.init()
       const exists = await vfs.exists('/imports/test-data.csv')
       expect(exists).toBe(true)
@@ -173,7 +173,7 @@ Gadget,20`
     let vfs: any
 
     beforeAll(async () => {
-      vfs = brain.vfs()
+      vfs = brain.vfs
       await vfs.init()
     })
 
@@ -348,7 +348,7 @@ Gadget,20`
       console.log('\n📋 Test: neural.clusters() VFS filtering')
 
       // Create VFS files
-      const vfs = brain.vfs()
+      const vfs = brain.vfs
       await vfs.writeFile('/cluster-test1.txt', 'VFS file content')
       await vfs.writeFile('/cluster-test2.txt', 'Another VFS file')
 
@@ -416,7 +416,7 @@ Gadget,20`
     it('should handle VFS file operations at scale', async () => {
       console.log('\n📋 Test: VFS operations at scale')
 
-      const vfs = brain.vfs()
+      const vfs = brain.vfs
       const start = Date.now()
 
       // Create 20 files
diff --git a/tests/integration/vfs-and-graph-entities.test.ts b/tests/integration/vfs-and-graph-entities.test.ts
index 9fb15c3b..0850f764 100644
--- a/tests/integration/vfs-and-graph-entities.test.ts
+++ b/tests/integration/vfs-and-graph-entities.test.ts
@@ -89,7 +89,7 @@ describe('VFS + Graph Entities Integration Test', () => {
     console.log('='.repeat(80))
 
     // Initialize VFS
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
 
     // ASSERTION 4: VFS directory structure exists
diff --git a/tests/integration/vfs-api-wiring.test.ts b/tests/integration/vfs-api-wiring.test.ts
index 137f3bd9..9911b320 100644
--- a/tests/integration/vfs-api-wiring.test.ts
+++ b/tests/integration/vfs-api-wiring.test.ts
@@ -47,7 +47,7 @@ describe('VFS API Wiring Verification', () => {
     })
 
     // Create VFS file
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
     await vfs.writeFile('/typescript.md', 'TypeScript programming guide')
 
@@ -81,7 +81,7 @@ describe('VFS API Wiring Verification', () => {
   it('should verify vfs.search() finds VFS files', async () => {
     console.log('\n📋 Test 2: vfs.search() finds VFS files')
 
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()  // Required before using VFS operations
 
     // Create test files
@@ -111,7 +111,7 @@ describe('VFS API Wiring Verification', () => {
   it('should verify vfs.findSimilar() finds similar VFS files', async () => {
     console.log('\n📋 Test 3: vfs.findSimilar() finds similar VFS files')
 
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()  // Required before using VFS operations
 
     // Create similar files
@@ -143,7 +143,7 @@ describe('VFS API Wiring Verification', () => {
   it('should verify vfs.searchEntities() finds VFS entities', async () => {
     console.log('\n📋 Test 4: vfs.searchEntities() finds VFS entities')
 
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()  // Required before using VFS operations
 
     // Create entity in VFS (if supported)
@@ -164,7 +164,7 @@ describe('VFS API Wiring Verification', () => {
   it('should verify VFS semantic projections work', async () => {
     console.log('\n📋 Test 5: VFS semantic projections')
 
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()  // Required before using VFS operations
 
     // Create files with metadata for projections
@@ -282,7 +282,7 @@ describe('VFS API Wiring Verification', () => {
   it('should verify production scale performance', async () => {
     console.log('\n📋 Test 8: Production scale performance')
 
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()  // Required before using VFS operations
 
     // Create batch of files
diff --git a/tests/integration/vfs-debug.test.ts b/tests/integration/vfs-debug.test.ts
index a5bf99b1..e0f0563b 100644
--- a/tests/integration/vfs-debug.test.ts
+++ b/tests/integration/vfs-debug.test.ts
@@ -14,7 +14,7 @@ describe('VFS Debug', () => {
     console.log('✅ Brain initialized')
 
     // Get VFS and initialize
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
 
     console.log('✅ VFS initialized')
diff --git a/tests/integration/vfs-import-verification.test.ts b/tests/integration/vfs-import-verification.test.ts
index 37688e75..3241be4e 100644
--- a/tests/integration/vfs-import-verification.test.ts
+++ b/tests/integration/vfs-import-verification.test.ts
@@ -100,7 +100,7 @@ describe('VFS Import Verification (Workshop Bug Investigation)', () => {
     console.log('\n📂 Step 3: Initialize VFS and query...')
 
     // Get VFS instance
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     console.log('   - Got VFS instance')
 
     // Initialize VFS
@@ -180,10 +180,10 @@ describe('VFS Import Verification (Workshop Bug Investigation)', () => {
     })
 
     console.log('📂 Get VFS (should be initialized by import)...')
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
 
     // AFTER REFACTOR: This should work without calling vfs.init()
-    // Because VFSStructureGenerator uses brain.vfs() which caches the instance
+    // Because VFSStructureGenerator uses brain.vfs which caches the instance
     console.log('🔍 Query root (without manual init)...')
 
     try {
@@ -238,7 +238,7 @@ describe('VFS Import Verification (Workshop Bug Investigation)', () => {
 
     // Workshop team's check: Initialize VFS
     console.log('\n📂 Initializing VFS (Workshop fix)...')
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
 
     // Workshop team's check: Query root
diff --git a/tests/integration/vfs-knowledge-separation.test.ts b/tests/integration/vfs-knowledge-separation.test.ts
index 1d6e8744..16882990 100644
--- a/tests/integration/vfs-knowledge-separation.test.ts
+++ b/tests/integration/vfs-knowledge-separation.test.ts
@@ -42,7 +42,7 @@ describe('VFS-Knowledge Separation (Option 3C)', () => {
 
   it('should exclude VFS entities from brain.find() by default', async () => {
     // Create VFS file entity
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
     await vfs.mkdir('/docs', { recursive: true })
     await vfs.writeFile('/docs/readme.md', '# Hello World')
diff --git a/tests/manual/simple-vfs-filter-test.test.ts b/tests/manual/simple-vfs-filter-test.test.ts
index c70b7161..4b8065f7 100644
--- a/tests/manual/simple-vfs-filter-test.test.ts
+++ b/tests/manual/simple-vfs-filter-test.test.ts
@@ -47,7 +47,7 @@ describe('Simple VFS Filter Test', () => {
 
     // 2. Create VFS file
     console.log('\n2. Creating VFS file...')
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
     await vfs.writeFile('/test.txt', 'VFS file')
     console.log('   VFS file created')
diff --git a/tests/manual/vfs-isvfs-diagnostic.test.ts b/tests/manual/vfs-isvfs-diagnostic.test.ts
index b90667b9..41d6002f 100644
--- a/tests/manual/vfs-isvfs-diagnostic.test.ts
+++ b/tests/manual/vfs-isvfs-diagnostic.test.ts
@@ -35,7 +35,7 @@ describe('isVFS Flag Diagnostic', () => {
 
   it('should show what entities are created', async () => {
     // Create VFS file
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
     await vfs.writeFile('/test.txt', 'Hello World')
 
diff --git a/tests/manual/vfs-multiple-init-diagnostic.test.ts b/tests/manual/vfs-multiple-init-diagnostic.test.ts
index e07b8c5d..b6a589fb 100644
--- a/tests/manual/vfs-multiple-init-diagnostic.test.ts
+++ b/tests/manual/vfs-multiple-init-diagnostic.test.ts
@@ -44,7 +44,7 @@ describe('VFS Multiple Init Diagnostic', () => {
   })
 
   it('should not create duplicate roots when calling vfs.init() multiple times on SAME instance', async () => {
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
 
     // Call init multiple times
     await vfs.init()
@@ -74,10 +74,10 @@ describe('VFS Multiple Init Diagnostic', () => {
 
   it('should not create duplicate roots when creating MULTIPLE VFS instances (Workshop scenario)', async () => {
     // Simulate Workshop's scenario: Getting VFS on multiple requests
-    // brain.vfs() returns cached instance, so this should be safe
-    const vfs1 = brain.vfs()
-    const vfs2 = brain.vfs()
-    const vfs3 = brain.vfs()
+    // brain.vfs returns cached instance, so this should be safe
+    const vfs1 = brain.vfs
+    const vfs2 = brain.vfs
+    const vfs3 = brain.vfs
 
     await vfs1.init()
     await vfs2.init()
@@ -142,7 +142,7 @@ describe('VFS Multiple Init Diagnostic', () => {
 
   it('should verify readdir works after multiple inits', async () => {
     // Create a test directory
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.mkdir('/test-dir', { recursive: true })
     await vfs.writeFile('/test-dir/test.txt', 'Hello')
 
@@ -170,7 +170,7 @@ describe('VFS Multiple Init Diagnostic', () => {
   })
 
   it('should show if Contains relationships are created', async () => {
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
 
     // Get root entity ID using workaround
     const collections = await brain.find({
diff --git a/tests/manual/vfs-search-debug.test.ts b/tests/manual/vfs-search-debug.test.ts
index 59954e7c..e4423ad3 100644
--- a/tests/manual/vfs-search-debug.test.ts
+++ b/tests/manual/vfs-search-debug.test.ts
@@ -33,7 +33,7 @@ describe('VFS Search Debug', () => {
   })
 
   it('should debug vfs.search() results', async () => {
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
     await vfs.writeFile('/test.txt', 'Hello world test content')
 
diff --git a/tests/manual/vfs-where-clause-test.test.ts b/tests/manual/vfs-where-clause-test.test.ts
index c75e7801..83ede49c 100644
--- a/tests/manual/vfs-where-clause-test.test.ts
+++ b/tests/manual/vfs-where-clause-test.test.ts
@@ -37,7 +37,7 @@ describe('VFS Where Clause Diagnostic', () => {
   })
 
   it('should find root entity using where clause', async () => {
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
 
     // Method 1: Where clause (FIXED in v4.3.3!)
@@ -84,7 +84,7 @@ describe('VFS Where Clause Diagnostic', () => {
   })
 
   it('should find regular VFS files using where clause', async () => {
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.mkdir('/test', { recursive: true })
     await vfs.writeFile('/test/hello.txt', 'Hello World')
 
diff --git a/tests/unit/brainy-core.unit.test.ts b/tests/unit/brainy-core.unit.test.ts
index 9705846a..93754331 100644
--- a/tests/unit/brainy-core.unit.test.ts
+++ b/tests/unit/brainy-core.unit.test.ts
@@ -89,16 +89,17 @@ describe('Brainy 3.0 Core (Unit Tests)', () => {
     })
 
     it('should handle non-existent IDs according to API contract', async () => {
-      const fakeId = 'non-existent-id'
-      
+      // Use valid UUID format (stricter validation in v5.1.0)
+      const fakeId = '00000000-0000-0000-0000-000000000000'
+
       expect(await brain.get(fakeId)).toBeNull()
-      
+
       // update should handle non-existent ID gracefully
-      await expect(brain.update({ 
-        id: fakeId, 
-        data: { test: 'data' } 
+      await expect(brain.update({
+        id: fakeId,
+        data: { test: 'data' }
       })).rejects.toThrow()
-      
+
       // delete should not throw for non-existent ID
       await expect(brain.delete(fakeId)).resolves.not.toThrow()
     })
diff --git a/tests/unit/type-filtering.unit.test.ts b/tests/unit/type-filtering.unit.test.ts
index 741ab41c..c24af8d6 100644
--- a/tests/unit/type-filtering.unit.test.ts
+++ b/tests/unit/type-filtering.unit.test.ts
@@ -96,9 +96,17 @@ describe('Type Filtering (Workshop Team Issue)', () => {
     await brain.add({ data: 'Location 1', type: NounType.Location })
     await brain.add({ data: 'Concept 1', type: NounType.Concept })
 
+    // v5.1.0: VFS auto-initialization creates root directory
+    // So we now have 4 entities: 3 added + 1 root directory
     const results = await brain.find({ limit: 100 })
 
-    expect(results.length).toBe(3)
+    expect(results.length).toBeGreaterThanOrEqual(3)
+
+    // Verify our entities are included
+    const types = results.map(r => r.type)
+    expect(types).toContain('person')
+    expect(types).toContain('location')
+    expect(types).toContain('concept')
   })
 
   it('should verify entity type is set correctly', async () => {
diff --git a/tests/unit/workshop-vfs-diagnostic.test.ts b/tests/unit/workshop-vfs-diagnostic.test.ts
index f7171177..9edb5ff1 100644
--- a/tests/unit/workshop-vfs-diagnostic.test.ts
+++ b/tests/unit/workshop-vfs-diagnostic.test.ts
@@ -39,7 +39,7 @@ describe('Workshop VFS Diagnostic', () => {
     // Step 2: Use VFS to create files
     console.log('2️⃣  Creating VFS files...\n')
 
-    const vfs = brain.vfs()
+    const vfs = brain.vfs
     await vfs.init()
     await vfs.mkdir('/test', { recursive: true })
 
diff --git a/tests/vfs/vfs-bug-fixes.unit.test.ts b/tests/vfs/vfs-bug-fixes.unit.test.ts
index 82d13468..66f02e05 100644
--- a/tests/vfs/vfs-bug-fixes.unit.test.ts
+++ b/tests/vfs/vfs-bug-fixes.unit.test.ts
@@ -21,7 +21,7 @@ describe('VFS Bug Fixes', () => {
       embeddingModel: 'Q8'
     })
     await brain.init()
-    vfs = brain.vfs()
+    vfs = brain.vfs
     await vfs.init()
   })
 
diff --git a/tests/vfs/vfs-initialization.unit.test.ts b/tests/vfs/vfs-initialization.unit.test.ts
index 22b60260..9e7e98be 100644
--- a/tests/vfs/vfs-initialization.unit.test.ts
+++ b/tests/vfs/vfs-initialization.unit.test.ts
@@ -1,7 +1,7 @@
 /**
  * VFS Initialization Tests
  *
- * Tests proper VFS initialization patterns to prevent common errors
+ * Tests v5.1.0+ auto-initialization behavior
  */
 
 import { describe, it, expect } from 'vitest'
@@ -10,97 +10,55 @@ import { Brainy } from '../../src/brainy.js'
 
 describe('VFS Initialization', () => {
 
-  describe('Common Initialization Errors', () => {
-    it('should fail if VFS is not initialized before use', async () => {
+  describe('Auto-Initialization (v5.1.0+)', () => {
+    it('should auto-initialize VFS during brain.init()', async () => {
       const brain = new Brainy({
         storage: { type: 'memory' },
         silent: true
       })
       await brain.init()
 
-      const vfs = brain.vfs()
-      // Attempting to use VFS without calling init()
+      const vfs = brain.vfs
 
-      await expect(vfs.writeFile('/test.txt', 'Hello'))
-        .rejects.toThrow('VFS not initialized')
-
-      await expect(vfs.readdir('/'))
-        .rejects.toThrow('VFS not initialized')
-    })
-  })
-
-  describe('Correct Initialization Pattern', () => {
-    it('should work when VFS is properly initialized', async () => {
-      // Step 1: Initialize Brainy
-      const brain = new Brainy({
-        storage: { type: 'memory' },
-        silent: true
-      })
-      await brain.init()
-
-      // Step 2: Get VFS instance
-      const vfs = brain.vfs()
-
-      // Step 3: Initialize VFS - this creates the root directory
-      await vfs.init()
-
-      // Now VFS operations work correctly
+      // VFS is ready to use immediately after brain.init()
       await vfs.writeFile('/test.txt', 'Hello World')
-      await vfs.writeFile('/data.json', '{"key": "value"}')
+      const content = await vfs.readFile('/test.txt')
+      expect(content.toString()).toBe('Hello World')
 
-      // Root directory can be listed
-      const entries = await vfs.readdir('/')
-      expect(entries).toContain('test.txt')
-      expect(entries).toContain('data.json')
-
-      // Root directory stats are available
-      const stats = await vfs.stat('/')
-      expect(stats.isDirectory()).toBe(true)
-
-      // Cleanup
-      await vfs.close()
       await brain.close()
     })
 
-    it('should automatically create root directory on init', async () => {
+    it('should automatically create root directory on brain.init()', async () => {
       const brain = new Brainy({
         storage: { type: 'memory' },
         silent: true
       })
       await brain.init()
 
-      const vfs = brain.vfs()
+      const vfs = brain.vfs
 
-      // Before init, operations fail
-      await expect(vfs.exists('/'))
-        .rejects.toThrow('VFS not initialized')
-
-      // After init, root exists
-      await vfs.init()
+      // Root directory exists after brain.init()
       expect(await vfs.exists('/')).toBe(true)
 
       // Root is a directory
       const stats = await vfs.stat('/')
       expect(stats.isDirectory()).toBe(true)
 
-      // Can list empty root
+      // Can list root directory
       const entries = await vfs.readdir('/')
       expect(Array.isArray(entries)).toBe(true)
-      expect(entries).toEqual([])
 
-      await vfs.close()
       await brain.close()
     })
 
-    it('should handle nested directories after initialization', async () => {
+    it('should handle nested directories after brain.init()', async () => {
       const brain = new Brainy({
         storage: { type: 'memory' },
         silent: true
       })
       await brain.init()
 
-      const vfs = brain.vfs()
-      await vfs.init()
+      const vfs = brain.vfs
 
       // Create nested structure
       await vfs.mkdir('/documents')
@@ -119,8 +77,30 @@ describe('VFS Initialization', () => {
       const reportEntries = await vfs.readdir('/documents/reports')
       expect(reportEntries).toContain('q1.txt')
 
-      await vfs.close()
+      await brain.close()
+    })
+
+    it('should work with VFS operations immediately', async () => {
+      const brain = new Brainy({
+        storage: { type: 'memory' },
+        silent: true
+      })
+      await brain.init()
+
+      const vfs = brain.vfs
+
+      // All VFS operations work immediately
+      await vfs.writeFile('/test.txt', 'Hello')
+      await vfs.writeFile('/data.json', '{"key": "value"}')
+
+      const entries = await vfs.readdir('/')
+      expect(entries).toContain('test.txt')
+      expect(entries).toContain('data.json')
+
+      const testContent = await vfs.readFile('/test.txt')
+      expect(testContent.toString()).toBe('Hello')
+
       await brain.close()
     })
   })
-})
\ No newline at end of file
+})
diff --git a/tests/vfs/vfs.unit.test.ts b/tests/vfs/vfs.unit.test.ts
index 447ce0ff..8cdf4f5b 100644
--- a/tests/vfs/vfs.unit.test.ts
+++ b/tests/vfs/vfs.unit.test.ts
@@ -23,7 +23,7 @@ describe('VirtualFileSystem - Production Tests', () => {
     await brain.init()
 
     // Create VFS on top of Brainy
-    vfs = brain.vfs()
+    vfs = brain.vfs
     await vfs.init()
   })