diff --git a/src/hooks/useThemeManager.test.ts b/src/hooks/useThemeManager.test.ts
index 37712664..9e1f0075 100644
--- a/src/hooks/useThemeManager.test.ts
+++ b/src/hooks/useThemeManager.test.ts
@@ -105,7 +105,7 @@ describe('useThemeManager', () => {
       await result.current.switchTheme('dark')
     })
 
-    expect(mockInvokeFn).toHaveBeenCalledWith('set_active_theme', { vault_path: '/vault', theme_id: 'dark' })
+    expect(mockInvokeFn).toHaveBeenCalledWith('set_active_theme', { vaultPath: '/vault', themeId: 'dark' })
     expect(result.current.activeThemeId).toBe('dark')
   })
 
@@ -140,7 +140,7 @@ describe('useThemeManager', () => {
     })
 
     expect(newId).toBe('new-theme-id')
-    expect(mockInvokeFn).toHaveBeenCalledWith('create_theme', { vault_path: '/vault', source_id: 'default' })
+    expect(mockInvokeFn).toHaveBeenCalledWith('create_theme', { vaultPath: '/vault', sourceId: 'default' })
     // Should reload after creation
     const listCalls = mockInvokeFn.mock.calls.filter(c => c[0] === 'list_themes')
     expect(listCalls.length).toBeGreaterThanOrEqual(2)
@@ -156,7 +156,7 @@ describe('useThemeManager', () => {
       await result.current.createTheme()
     })
 
-    expect(mockInvokeFn).toHaveBeenCalledWith('create_theme', { vault_path: '/vault', source_id: null })
+    expect(mockInvokeFn).toHaveBeenCalledWith('create_theme', { vaultPath: '/vault', sourceId: null })
   })
 
   it('handles load failure gracefully', async () => {
diff --git a/src/hooks/useThemeManager.ts b/src/hooks/useThemeManager.ts
index 6377b824..4dc3b0f9 100644
--- a/src/hooks/useThemeManager.ts
+++ b/src/hooks/useThemeManager.ts
@@ -74,8 +74,8 @@ export function useThemeManager(vaultPath: string | null): ThemeManager {
     if (!vaultPath) return
     try {
       const [themeList, settings] = await Promise.all([
-        tauriCall<ThemeFile[]>('list_themes', { vault_path: vaultPath }),
-        tauriCall<VaultSettings>('get_vault_settings', { vault_path: vaultPath }),
+        tauriCall<ThemeFile[]>('list_themes', { vaultPath }),
+        tauriCall<VaultSettings>('get_vault_settings', { vaultPath }),
       ])
       setThemes(themeList)
       setActiveThemeId(settings.theme)
@@ -97,7 +97,7 @@ export function useThemeManager(vaultPath: string | null): ThemeManager {
   const switchTheme = useCallback(async (themeId: string) => {
     if (!vaultPath) return
     try {
-      await tauriCall<null>('set_active_theme', { vault_path: vaultPath, theme_id: themeId })
+      await tauriCall<null>('set_active_theme', { vaultPath, themeId })
       setActiveThemeId(themeId)
     } catch (err) {
       console.error('Failed to switch theme:', err)
@@ -108,8 +108,8 @@ export function useThemeManager(vaultPath: string | null): ThemeManager {
     if (!vaultPath) return ''
     try {
       const newId = await tauriCall<string>('create_theme', {
-        vault_path: vaultPath,
-        source_id: sourceId ?? null,
+        vaultPath,
+        sourceId: sourceId ?? null,
       })
       await loadThemes()
       await switchTheme(newId)
diff --git a/src/mock-tauri/mock-handlers.ts b/src/mock-tauri/mock-handlers.ts
index 00faae39..94c5ca01 100644
--- a/src/mock-tauri/mock-handlers.ts
+++ b/src/mock-tauri/mock-handlers.ts
@@ -252,16 +252,16 @@ export const mockHandlers: Record<string, (args: any) => any> = {
   create_getting_started_vault: () => '/Users/mock/Documents/Laputa',
   register_mcp_tools: () => 'registered',
   list_themes: (): ThemeFile[] => [...mockThemes],
-  get_theme: (args: { theme_id: string }): ThemeFile => {
-    const t = mockThemes.find(t => t.id === args.theme_id)
-    if (!t) throw new Error(`Theme not found: ${args.theme_id}`)
+  get_theme: (args: { themeId: string }): ThemeFile => {
+    const t = mockThemes.find(t => t.id === args.themeId)
+    if (!t) throw new Error(`Theme not found: ${args.themeId}`)
     return { ...t }
   },
   get_vault_settings: (): VaultSettings => ({ ...mockVaultSettings }),
   save_vault_settings: (args: { settings: VaultSettings }) => { mockVaultSettings = { ...args.settings }; return null },
-  set_active_theme: (args: { theme_id: string }) => { mockVaultSettings.theme = args.theme_id; return null },
-  create_theme: (args: { source_id?: string }): string => {
-    const sourceId = args.source_id ?? 'default'
+  set_active_theme: (args: { themeId: string }) => { mockVaultSettings.theme = args.themeId; return null },
+  create_theme: (args: { sourceId?: string }): string => {
+    const sourceId = args.sourceId ?? 'default'
     const source = mockThemes.find(t => t.id === sourceId) ?? mockThemes[0]
     const newId = `untitled-${mockThemes.length}`
     mockThemes.push({ ...source, id: newId, name: 'Untitled Theme' })