diff --git a/apps/x/apps/renderer/src/App.tsx b/apps/x/apps/renderer/src/App.tsx
index 2f4337a9..f9019ede 100644
--- a/apps/x/apps/renderer/src/App.tsx
+++ b/apps/x/apps/renderer/src/App.tsx
@@ -30,7 +30,7 @@ import { BgTasksView } from '@/components/bg-tasks-view';
 import { EmailView } from '@/components/email-view';
 import { WorkspaceView } from '@/components/workspace-view';
 import { CodingRunBlock } from '@/components/coding-run';
-import { KnowledgeView } from '@/components/knowledge-view';
+import { KnowledgeView, type KnowledgeViewMode } from '@/components/knowledge-view';
 import { ChatHistoryView } from '@/components/chat-history-view';
 import { HomeView } from '@/components/home-view';
 import { MeetingsView } from '@/components/meetings-view';
@@ -591,7 +591,7 @@ type ViewState =
   | { type: 'live-notes' }
   | { type: 'email' }
   | { type: 'workspace'; path?: string }
-  | { type: 'knowledge-view'; folderPath?: string }
+  | { type: 'knowledge-view'; folderPath?: string; mode?: KnowledgeViewMode }
   | { type: 'chat-history' }
   | { type: 'home' }
   | { type: 'code' }
@@ -602,7 +602,7 @@ function viewStatesEqual(a: ViewState, b: ViewState): boolean {
   if (a.type === 'file' && b.type === 'file') return a.path === b.path
   if (a.type === 'task' && b.type === 'task') return a.name === b.name
   if (a.type === 'workspace' && b.type === 'workspace') return (a.path ?? '') === (b.path ?? '')
-  if (a.type === 'knowledge-view' && b.type === 'knowledge-view') return (a.folderPath ?? '') === (b.folderPath ?? '')
+  if (a.type === 'knowledge-view' && b.type === 'knowledge-view') return (a.folderPath ?? '') === (b.folderPath ?? '') && (a.mode ?? '') === (b.mode ?? '')
   return true // both graph
 }
 
@@ -652,7 +652,12 @@ function parseDeepLink(input: string): ViewState | null {
     }
     case 'knowledge-view': {
       const folderPath = params.get('folderPath')
-      return { type: 'knowledge-view', folderPath: folderPath ?? undefined }
+      const mode = params.get('mode')
+      return {
+        type: 'knowledge-view',
+        folderPath: folderPath ?? undefined,
+        mode: mode === 'graph' || mode === 'basis' || mode === 'files' ? mode : undefined,
+      }
     }
     case 'chat-history':
       return { type: 'chat-history' }
@@ -775,6 +780,7 @@ function App() {
   const [isWorkspaceOpen, setIsWorkspaceOpen] = useState(false)
   const [workspaceInitialPath, setWorkspaceInitialPath] = useState<string | null>(null)
   const [isKnowledgeViewOpen, setIsKnowledgeViewOpen] = useState(false)
+  const [knowledgeViewMode, setKnowledgeViewMode] = useState<KnowledgeViewMode>('graph')
   // Folder being browsed inside the knowledge view (null = root overview).
   // Lives in ViewState so folder drill-down participates in back/forward history.
   const [knowledgeViewFolderPath, setKnowledgeViewFolderPath] = useState<string | null>(null)
@@ -1197,7 +1203,7 @@ function App() {
     if (isBgTasksTabPath(tab.path)) return 'Background tasks'
     if (isEmailTabPath(tab.path)) return 'Email'
     if (isWorkspaceTabPath(tab.path)) return 'Workspace'
-    if (isKnowledgeViewTabPath(tab.path)) return 'Notes'
+    if (isKnowledgeViewTabPath(tab.path)) return 'Brain'
     if (isChatHistoryTabPath(tab.path)) return 'Chat history'
     if (isHomeTabPath(tab.path)) return 'Home'
     if (isCodeTabPath(tab.path)) return 'Code'
@@ -3627,14 +3633,14 @@ function App() {
     if (isLiveNotesOpen) return { type: 'live-notes' }
     if (isSuggestedTopicsOpen) return { type: 'suggested-topics' }
     if (isWorkspaceOpen) return { type: 'workspace', path: workspaceInitialPath ?? undefined }
-    if (isKnowledgeViewOpen) return { type: 'knowledge-view', folderPath: knowledgeViewFolderPath ?? undefined }
+    if (isKnowledgeViewOpen) return { type: 'knowledge-view', folderPath: knowledgeViewFolderPath ?? undefined, mode: knowledgeViewMode }
     if (isChatHistoryOpen) return { type: 'chat-history' }
     if (isHomeOpen) return { type: 'home' }
     if (isCodeOpen) return { type: 'code' }
     if (selectedPath) return { type: 'file', path: selectedPath }
     if (isGraphOpen) return { type: 'graph' }
     return { type: 'chat', runId }
-  }, [selectedBackgroundTask, isEmailOpen, isMeetingsOpen, isLiveNotesOpen, isBgTasksOpen, isSuggestedTopicsOpen, selectedPath, isGraphOpen, isWorkspaceOpen, isKnowledgeViewOpen, knowledgeViewFolderPath, isChatHistoryOpen, isHomeOpen, isCodeOpen, workspaceInitialPath, runId])
+  }, [selectedBackgroundTask, isEmailOpen, isMeetingsOpen, isLiveNotesOpen, isBgTasksOpen, isSuggestedTopicsOpen, selectedPath, isGraphOpen, isWorkspaceOpen, isKnowledgeViewOpen, knowledgeViewFolderPath, knowledgeViewMode, isChatHistoryOpen, isHomeOpen, isCodeOpen, workspaceInitialPath, runId])
 
   const appendUnique = useCallback((stack: ViewState[], entry: ViewState) => {
     const last = stack[stack.length - 1]
@@ -3997,6 +4003,7 @@ function App() {
         setIsEmailOpen(false)
         setIsWorkspaceOpen(false)
         setIsKnowledgeViewOpen(true)
+        setKnowledgeViewMode(view.mode ?? (view.folderPath ? 'files' : 'graph'))
         setKnowledgeViewFolderPath(view.folderPath ?? null)
         setIsChatHistoryOpen(false)
       setIsHomeOpen(false)
@@ -4223,10 +4230,9 @@ function App() {
     setBaseConfigByPath((prev) => ({ ...prev, [path]: config }))
   }, [])
 
-  const handleBaseSave = useCallback(async (name: string | null) => {
-    if (!selectedPath) return
-    const isDefault = selectedPath === BASES_DEFAULT_TAB_PATH
-    const config = baseConfigByPath[selectedPath] ?? DEFAULT_BASE_CONFIG
+  const handleBaseSave = useCallback(async (path: string, name: string | null) => {
+    const isDefault = path === BASES_DEFAULT_TAB_PATH
+    const config = baseConfigByPath[path] ?? DEFAULT_BASE_CONFIG
 
     if (isDefault && name) {
       // Save as new base file
@@ -4250,14 +4256,14 @@ function App() {
       // Save in place
       try {
         await window.ipc.invoke('workspace:writeFile', {
-          path: selectedPath,
+          path,
           data: JSON.stringify(config, null, 2),
         })
       } catch (err) {
         console.error('Failed to save base:', err)
       }
     }
-  }, [selectedPath, baseConfigByPath, loadDirectory, navigateToView])
+  }, [baseConfigByPath, loadDirectory, navigateToView])
 
   // External search set by app-navigation tool (passed to BasesView)
   const [externalBaseSearch, setExternalBaseSearch] = useState<string | undefined>(undefined)
@@ -5121,8 +5127,10 @@ function App() {
     },
   }), [knowledgeFiles, recentWikiFiles, openWikiLink, ensureWikiFile])
 
+  const isBrainGraphOpen = isKnowledgeViewOpen && knowledgeViewMode === 'graph'
+
   useEffect(() => {
-    if (!isGraphOpen) return
+    if (!isGraphOpen && !isBrainGraphOpen) return
     let cancelled = false
 
     const buildGraph = async () => {
@@ -5237,7 +5245,7 @@ function App() {
     return () => {
       cancelled = true
     }
-  }, [isGraphOpen, knowledgeFilePaths])
+  }, [isGraphOpen, isBrainGraphOpen, knowledgeFilePaths])
 
   const renderConversationItem = (
     item: ConversationItem,
@@ -5760,12 +5768,44 @@ function App() {
                       revealInFileManager: knowledgeActions.revealInFileManager,
                       onOpenInNewTab: knowledgeActions.onOpenInNewTab,
                     }}
+                    mode={knowledgeViewMode}
+                    onModeChange={setKnowledgeViewMode}
+                    graphContent={(
+                      <GraphView
+                        nodes={graphData.nodes}
+                        edges={graphData.edges}
+                        isLoading={false}
+                        error={graphStatus === 'error' ? (graphError ?? 'Failed to build graph') : null}
+                        onSelectNode={(path) => {
+                          navigateToFile(path)
+                        }}
+                      />
+                    )}
+                    basisContent={(
+                      <BasesView
+                        tree={tree}
+                        onSelectNote={(path) => navigateToFile(path)}
+                        config={baseConfigByPath[BASES_DEFAULT_TAB_PATH] ?? DEFAULT_BASE_CONFIG}
+                        onConfigChange={(cfg) => handleBaseConfigChange(BASES_DEFAULT_TAB_PATH, cfg)}
+                        isDefaultBase
+                        onSave={(name) => void handleBaseSave(BASES_DEFAULT_TAB_PATH, name)}
+                        externalSearch={externalBaseSearch}
+                        onExternalSearchConsumed={() => setExternalBaseSearch(undefined)}
+                        actions={{
+                          rename: knowledgeActions.rename,
+                          remove: knowledgeActions.remove,
+                          copyPath: knowledgeActions.copyPath,
+                          revealInFileManager: knowledgeActions.revealInFileManager,
+                        }}
+                      />
+                    )}
                     folderPath={knowledgeViewFolderPath}
-                    onNavigateFolder={(path) => { void navigateToView({ type: 'knowledge-view', folderPath: path ?? undefined }) }}
+                    onNavigateFolder={(path) => {
+                      setKnowledgeViewMode('files')
+                      void navigateToView({ type: 'knowledge-view', folderPath: path ?? undefined, mode: 'files' })
+                    }}
                     onOpenNote={(path) => navigateToFile(path)}
-                    onOpenGraph={() => knowledgeActions.openGraph()}
                     onOpenSearch={() => { setSearchDefaultScope('knowledge'); setIsSearchOpen(true) }}
-                    onOpenBases={() => knowledgeActions.openBases()}
                     onVoiceNoteCreated={handleVoiceNoteCreated}
                   />
                 </div>
@@ -5796,7 +5836,7 @@ function App() {
                     config={baseConfigByPath[selectedPath] ?? DEFAULT_BASE_CONFIG}
                     onConfigChange={(cfg) => handleBaseConfigChange(selectedPath, cfg)}
                     isDefaultBase={selectedPath === BASES_DEFAULT_TAB_PATH}
-                    onSave={(name) => void handleBaseSave(name)}
+                    onSave={(name) => void handleBaseSave(selectedPath, name)}
                     externalSearch={externalBaseSearch}
                     onExternalSearchConsumed={() => setExternalBaseSearch(undefined)}
                     actions={{
diff --git a/apps/x/apps/renderer/src/components/knowledge-view.tsx b/apps/x/apps/renderer/src/components/knowledge-view.tsx
index e7ebe780..0945ffcf 100644
--- a/apps/x/apps/renderer/src/components/knowledge-view.tsx
+++ b/apps/x/apps/renderer/src/components/knowledge-view.tsx
@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { useCallback, useEffect, useMemo, useRef, useState, type ReactNode } from 'react'
 import {
   ArrowLeft,
   ChevronRight,
@@ -46,17 +46,21 @@ export type KnowledgeViewActions = {
   onOpenInNewTab?: (path: string) => void
 }
 
+export type KnowledgeViewMode = 'graph' | 'basis' | 'files'
+
 type KnowledgeViewProps = {
   tree: TreeNode[]
   actions: KnowledgeViewActions
+  mode: KnowledgeViewMode
+  onModeChange: (mode: KnowledgeViewMode) => void
+  graphContent: ReactNode
+  basisContent: ReactNode
   // Folder currently being browsed (null = root overview). Controlled by the
   // app so drill-down participates in the global back/forward history.
   folderPath: string | null
   onNavigateFolder: (path: string | null) => void
   onOpenNote: (path: string) => void
-  onOpenGraph: () => void
   onOpenSearch: () => void
-  onOpenBases: () => void
   onVoiceNoteCreated?: (path: string) => void
 }
 
@@ -145,12 +149,14 @@ function displayName(node: TreeNode): string {
 export function KnowledgeView({
   tree,
   actions,
+  mode,
+  onModeChange,
+  graphContent,
+  basisContent,
   folderPath,
   onNavigateFolder,
   onOpenNote,
-  onOpenGraph,
   onOpenSearch,
-  onOpenBases,
   onVoiceNoteCreated,
 }: KnowledgeViewProps) {
   const [renameTarget, setRenameTarget] = useState<string | null>(null)
@@ -184,27 +190,46 @@ export function KnowledgeView({
     <div className="flex h-full flex-col overflow-hidden">
       <div className="shrink-0 flex items-start justify-between gap-4 border-b border-border px-8 py-6">
         <div className="min-w-0">
-          <h1 className="text-2xl font-bold tracking-tight">Notes</h1>
+          <h1 className="text-2xl font-bold tracking-tight">Brain</h1>
           <p className="mt-1 text-sm text-muted-foreground">
             {totalNotes} {totalNotes === 1 ? 'note' : 'notes'} across {folders.length}{' '}
             {folders.length === 1 ? 'folder' : 'folders'}
           </p>
         </div>
         <div className="flex shrink-0 items-center gap-2">
+          <div className="inline-flex overflow-hidden rounded-lg border border-border bg-background">
+            <ViewModeButton
+              icon={Network}
+              label="Graph"
+              active={mode === 'graph'}
+              onClick={() => onModeChange('graph')}
+            />
+            <ViewModeButton
+              icon={Table2}
+              label="Base"
+              active={mode === 'basis'}
+              onClick={() => onModeChange('basis')}
+            />
+            <ViewModeButton
+              icon={FileText}
+              label="Files"
+              active={mode === 'files'}
+              onClick={() => onModeChange('files')}
+            />
+          </div>
           <VoiceNoteButton onNoteCreated={onVoiceNoteCreated} />
-          <SecondaryButton icon={SearchIcon} label="Search" onClick={onOpenSearch} />
-          <SecondaryButton icon={Network} label="Graph" onClick={onOpenGraph} />
-          <button
-            type="button"
-            onClick={() => actions.createNote(currentFolder?.path)}
-            className="inline-flex items-center gap-1.5 rounded-lg bg-primary px-3 py-1.5 text-sm font-medium text-primary-foreground transition-colors hover:bg-primary/90"
-          >
-            <FilePlus className="size-4" />
-            <span>New note</span>
-          </button>
         </div>
       </div>
 
+      {mode === 'graph' ? (
+        <div className="flex-1 min-h-0 overflow-hidden">
+          {graphContent}
+        </div>
+      ) : mode === 'basis' ? (
+        <div className="flex-1 min-h-0 overflow-hidden">
+          {basisContent}
+        </div>
+      ) : (
       <div className="flex-1 overflow-y-auto">
         <div className="mx-auto w-full max-w-3xl px-8 py-6">
           {currentFolder ? (
@@ -267,11 +292,12 @@ export function KnowledgeView({
           <QuickActions
             actions={actions}
             currentFolder={currentFolder}
-            onOpenBases={onOpenBases}
+            onOpenSearch={onOpenSearch}
             onFolderCreated={setRenameTarget}
           />
         </div>
       </div>
+      )}
     </div>
   )
 }
@@ -279,12 +305,12 @@ export function KnowledgeView({
 function QuickActions({
   actions,
   currentFolder,
-  onOpenBases,
+  onOpenSearch,
   onFolderCreated,
 }: {
   actions: KnowledgeViewActions
   currentFolder: TreeNode | null
-  onOpenBases: () => void
+  onOpenSearch: () => void
   onFolderCreated: (path: string) => void
 }) {
   // Inside a folder these target that folder; at the root they target knowledge/.
@@ -294,6 +320,7 @@ function QuickActions({
       <SectionHeader label="Quick actions" />
       <div className="flex flex-wrap gap-2">
         <QuickAction icon={FilePlus} label="New note" onClick={() => actions.createNote(parent)} />
+        <QuickAction icon={SearchIcon} label="Search" onClick={onOpenSearch} />
         <QuickAction
           icon={FolderPlus}
           label="New folder"
@@ -304,7 +331,6 @@ function QuickActions({
             } catch { /* ignore */ }
           }}
         />
-        <QuickAction icon={Table2} label="Open as base" onClick={onOpenBases} />
         <QuickAction
           icon={FolderOpen}
           label={`Reveal in ${getFileManagerName()}`}
@@ -315,20 +341,26 @@ function QuickActions({
   )
 }
 
-function SecondaryButton({
+function ViewModeButton({
   icon: Icon,
   label,
+  active,
   onClick,
 }: {
   icon: typeof SearchIcon
   label: string
+  active: boolean
   onClick: () => void
 }) {
   return (
     <button
       type="button"
       onClick={onClick}
-      className="inline-flex items-center gap-1.5 rounded-lg border border-border bg-background px-3 py-1.5 text-sm text-foreground transition-colors hover:bg-accent"
+      aria-pressed={active}
+      className={cn(
+        'inline-flex items-center gap-1.5 px-3 py-1.5 text-sm transition-colors',
+        active ? 'bg-accent text-foreground' : 'text-muted-foreground hover:bg-accent/60 hover:text-foreground',
+      )}
     >
       <Icon className="size-4" />
       <span>{label}</span>
@@ -532,7 +564,7 @@ function FolderDetail({
           onClick={() => onNavigate(null)}
           className="rounded-md px-1.5 py-1 text-muted-foreground transition-colors hover:bg-accent hover:text-foreground"
         >
-          Notes
+          Brain
         </button>
         {crumbs.map((c, i) => (
           <span key={c.path} className="flex min-w-0 items-center gap-1.5">
diff --git a/apps/x/apps/renderer/src/components/sidebar-content.tsx b/apps/x/apps/renderer/src/components/sidebar-content.tsx
index 8de6402a..986d76cc 100644
--- a/apps/x/apps/renderer/src/components/sidebar-content.tsx
+++ b/apps/x/apps/renderer/src/components/sidebar-content.tsx
@@ -819,7 +819,7 @@ export function SidebarContentPanel({
                 >
                   <FileText className="size-4 shrink-0" />
                   <div className="flex min-w-0 flex-1 flex-col">
-                    <span className="truncate">Knowledge</span>
+                    <span className="truncate">Brain</span>
                     {knowledgeUpdatedLabel && (
                       <span className="truncate text-[11px] text-muted-foreground">{knowledgeUpdatedLabel}</span>
                     )}
diff --git a/apps/x/packages/core/src/application/assistant/instructions.ts b/apps/x/packages/core/src/application/assistant/instructions.ts
index 8ffb7751..ed3576b0 100644
--- a/apps/x/packages/core/src/application/assistant/instructions.ts
+++ b/apps/x/packages/core/src/application/assistant/instructions.ts
@@ -158,6 +158,8 @@ Unlike other AI assistants that start cold every session, you have access to a l
 When a user asks you to prep them for a call with someone, you already know every prior decision, concerns they've raised, and commitments on both sides - because memory has been accumulating across every email and call, not reconstructed on demand.
 
 ## The Knowledge Graph
+The knowledge graph is the user's **Brain**. If the user says "my brain", "the brain", "look into your brain", "check my brain", "Brain", or similar, they mean the knowledge graph stored in \`knowledge/\`. Treat "Brain" and "knowledge graph" as the same thing.
+
 The knowledge graph is stored as plain markdown with Obsidian-style backlinks in \`knowledge/\` (inside the workspace). The folder is organized into these categories:
 - **Notes/** - Default location for user-authored notes. Create new notes here unless the user specifies a different folder.
 - **People/** - Notes on individuals, tracking relationships, decisions, and commitments