feat(settings): add per-story toggle to expand generation thinking by default

src/components/prose/GenerationThoughts.tsx

@@ -1,6 +1,8 @@
+import { useEffect, useState } from 'react'
 import {
   ChainOfThought,
   ChainOfThoughtContent,
+  ChainOfThoughtHeader,
   ChainOfThoughtStep,
 } from '@/components/ui/chain-of-thought'
 import { Loader2, Brain, Wrench, CheckCircle2, PenLine, FileText } from 'lucide-react'
@@ -31,33 +33,38 @@ export function GenerationThoughts({
   steps,
   streaming,
   hasText,
+  defaultExpanded = true,
 }: {
   steps: ThoughtStep[]
   streaming: boolean
   hasText: boolean
+  defaultExpanded?: boolean
 }) {
   // Determine if reasoning is still actively streaming (no text yet, last step is reasoning)
   const lastStep = steps[steps.length - 1]
   const isThinking = streaming && !hasText && lastStep?.type === 'reasoning'
 
+  // Open per the story setting while generating, then collapse once it completes
+  const [open, setOpen] = useState(defaultExpanded)
+  useEffect(() => {
+    setOpen(streaming ? defaultExpanded : false)
+  }, [streaming, defaultExpanded])
 
   return (
     <div className="mb-4" data-component-id="generation-thoughts-root">
-      <ChainOfThought defaultOpen={true}>
+      <ChainOfThought open={open} onOpenChange={setOpen}>
+        <ChainOfThoughtHeader>{isThinking ? 'Thinking' : 'Thoughts'}</ChainOfThoughtHeader>
         <ChainOfThoughtContent>
           {steps.map((step, i) => {
             if (step.type === 'reasoning') {
+              // Reasoning text sits directly under the header — the header is its label
               return (
-                <ChainOfThoughtStep
+                <div
                   key={`reasoning-${i}`}
-                  icon={Brain}
-                  label="Thinking"
-                  status={isThinking && i === steps.length - 1 ? 'active' : 'complete'}
+                  className="text-[0.625rem] text-muted-foreground italic font-mono whitespace-pre-wrap leading-relaxed max-h-[200px] overflow-y-auto"
                 >
-                  <div className="text-[0.625rem] text-muted-foreground italic font-mono whitespace-pre-wrap leading-relaxed max-h-[200px] overflow-y-auto">
-                    {step.text}
-                  </div>
-                </ChainOfThoughtStep>
+                  {step.text}
+                </div>
               )
             }
             if (step.type === 'prewriter-text') {

src/components/prose/ProseBlock.tsx

@@ -119,6 +119,10 @@ export const ProseBlock = memo(function ProseBlock({
   void isFirst
   void isLast
   const queryClient = useQueryClient()
+  const { data: story } = useQuery({
+    queryKey: ['story', storyId],
+    queryFn: () => api.stories.get(storyId),
+  })
   const [actionMode, setActionMode] = useState<'regenerate' | null>(null)
   const [showUndo, setShowUndo] = useState(false)
   const [isStreamingAction, setIsStreamingAction] = useState(false)
@@ -567,6 +571,7 @@ export const ProseBlock = memo(function ProseBlock({
             steps={actionThoughtSteps}
             streaming={isStreamingAction}
             hasText={!!streamedActionText}
+            defaultExpanded={story?.settings.expandThoughtsByDefault ?? true}
           />
         )}
         <StreamMarkdown

src/components/prose/ProseChainView.tsx

@@ -91,6 +91,10 @@ function StreamingSection({
   const [fragmentCountBeforeGeneration, setFragmentCountBeforeGeneration] = useState<number | null>(null)
   const isNearBottomRef = useRef(true)
   const queryClient = useQueryClient()
+  const { data: story } = useQuery({
+    queryKey: ['story', storyId],
+    queryFn: () => api.stories.get(storyId),
+  })
 
   // Track whether user is near the bottom of the scroll area
   useEffect(() => {
@@ -148,6 +152,7 @@ function StreamingSection({
                 steps={thoughtSteps}
                 streaming={isGenerating}
                 hasText={!!streamedText}
+                defaultExpanded={story?.settings.expandThoughtsByDefault ?? true}
               />
             )}
             <StreamMarkdown content={streamedText} streaming={isGenerating} variant="prose" />

src/components/sidebar/SettingsPanel.tsx

@@ -642,6 +642,14 @@ export function SettingsPanel({
                 label="Toggle disable thinking"
               />
             </SettingRow>
+            <SettingRow label="Expand thinking by default" description="Show the model's thinking expanded while it generates, instead of collapsed">
+              <Toggle
+                checked={story.settings.expandThoughtsByDefault ?? true}
+                onChange={(next) => updateMutation.mutate({ expandThoughtsByDefault: next })}
+                disabled={updateMutation.isPending}
+                label="Toggle expand thinking by default"
+              />
+            </SettingRow>
           </SettingsGroup>
 
           <SettingsGroup title="Context" description="How the prompt is assembled before generation starts.">

src/lib/api/settings.ts

@@ -28,6 +28,7 @@ export const settings = {
     guidedSceneSettingPrompt?: string
     guidedSuggestPrompt?: string
     disableThinking?: boolean
+    expandThoughtsByDefault?: boolean
   }) =>
     apiFetch<StoryMeta>(`/stories/${storyId}/settings`, {
       method: 'PATCH',

src/lib/api/types.ts

@@ -56,6 +56,7 @@ export interface StoryMeta {
     guidedSceneSettingPrompt?: string
     guidedSuggestPrompt?: string
     disableThinking?: boolean
+    expandThoughtsByDefault?: boolean
     /** erratanet provenance: installed-from pack and/or where this story is published. */
     erratanet?: {
       pack?: string

src/server/fragments/schema.ts

@@ -153,6 +153,7 @@ export const StoryMetaSchema = z.object({
       guidedSceneSettingPrompt: z.string().optional(),
       guidedSuggestPrompt: z.string().optional(),
       disableThinking: z.boolean().default(false),
+      expandThoughtsByDefault: z.boolean().default(true),
       // erratanet provenance. Absent for purely local stories.
       erratanet: z
         .object({
@@ -175,7 +176,7 @@ export const StoryMetaSchema = z.object({
         })
         .optional(),
     })
-    .default({ outputFormat: 'markdown', enabledPlugins: [], summarizationThreshold: 4, maxSteps: 10, modelOverrides: {}, generationMode: 'standard', clarifyBeforeGenerate: false, prewriterReasoning: 'normal', disableLibrarianAutoAnalysis: false, autoApplyLibrarianSuggestions: false, disableLibrarianDirections: false, disableLibrarianSuggestions: false, contextOrderMode: 'simple', fragmentOrder: [], customFragmentTypes: [], enabledBuiltinTools: [], contextCompact: { type: 'proseLimit', value: 10 }, summaryCompact: { maxCharacters: 12000, targetCharacters: 9000 }, enableHierarchicalSummary: false, disableThinking: false }),
+    .default({ outputFormat: 'markdown', enabledPlugins: [], summarizationThreshold: 4, maxSteps: 10, modelOverrides: {}, generationMode: 'standard', clarifyBeforeGenerate: false, prewriterReasoning: 'normal', disableLibrarianAutoAnalysis: false, autoApplyLibrarianSuggestions: false, disableLibrarianDirections: false, disableLibrarianSuggestions: false, contextOrderMode: 'simple', fragmentOrder: [], customFragmentTypes: [], enabledBuiltinTools: [], contextCompact: { type: 'proseLimit', value: 10 }, summaryCompact: { maxCharacters: 12000, targetCharacters: 9000 }, enableHierarchicalSummary: false, disableThinking: false, expandThoughtsByDefault: true }),
 })
 
 export type StoryMeta = z.infer<typeof StoryMetaSchema>

src/server/routes/stories.ts

@@ -42,6 +42,7 @@ export function storyRoutes(dataDir: string) {
           disableLibrarianDirections: false,
           disableLibrarianSuggestions: false,
           disableThinking: false,
+          expandThoughtsByDefault: true,
           contextOrderMode: 'simple' as const,
           fragmentOrder: [],
           customFragmentTypes: [],
@@ -170,6 +171,7 @@ export function storyRoutes(dataDir: string) {
         ...(body.summaryCompact !== undefined ? { summaryCompact: body.summaryCompact } : {}),
         ...(body.enableHierarchicalSummary !== undefined ? { enableHierarchicalSummary: body.enableHierarchicalSummary } : {}),
         ...(body.disableThinking !== undefined ? { disableThinking: body.disableThinking } : {}),
+        ...(body.expandThoughtsByDefault !== undefined ? { expandThoughtsByDefault: body.expandThoughtsByDefault } : {}),
       }
 
       const applyGuidedPrompt = (
@@ -238,6 +240,7 @@ export function storyRoutes(dataDir: string) {
         guidedSceneSettingPrompt: t.Optional(t.String()),
         guidedSuggestPrompt: t.Optional(t.String()),
         disableThinking: t.Optional(t.Boolean()),
+        expandThoughtsByDefault: t.Optional(t.Boolean()),
       }),
       detail: { summary: 'Update story settings' },
     })

tests/fragments/schema.test.ts

@@ -109,6 +109,7 @@ describe('StoryMetaSchema', () => {
     expect(result.settings.outputFormat).toBe('markdown')
     expect(result.settings.enabledPlugins).toEqual([])
     expect(result.settings.customFragmentTypes).toEqual([])
+    expect(result.settings.expandThoughtsByDefault).toBe(true)
   })
 
   it('accepts full story metadata', () => {