feat(ui): add model thinking selector

packages/ui/src/stores/preferences.tsx

@@ -39,6 +39,7 @@ export interface Preferences {
   lastUsedBinary?: string
   environmentVariables: Record<string, string>
   modelRecents: ModelPreference[]
+  modelThinkingSelections: Record<string, string>
   diffViewMode: DiffViewMode
   toolOutputExpansion: ExpansionPreference
   diagnosticsExpansion: ExpansionPreference
@@ -71,6 +72,7 @@ const defaultPreferences: Preferences = {
   showTimelineTools: true,
   environmentVariables: {},
   modelRecents: [],
+  modelThinkingSelections: {},
   diffViewMode: "split",
   toolOutputExpansion: "expanded",
   diagnosticsExpansion: "expanded",
@@ -102,6 +104,11 @@ function normalizePreferences(pref?: Partial<Preferences> & { agentModelSelectio
   const sourceModelRecents = sanitized.modelRecents ?? defaultPreferences.modelRecents
   const modelRecents = sourceModelRecents.map((item) => ({ ...item }))
 
+  const modelThinkingSelections = {
+    ...defaultPreferences.modelThinkingSelections,
+    ...(sanitized.modelThinkingSelections ?? {}),
+  }
+
   return {
     showThinkingBlocks: sanitized.showThinkingBlocks ?? defaultPreferences.showThinkingBlocks,
     thinkingBlocksExpansion: sanitized.thinkingBlocksExpansion ?? defaultPreferences.thinkingBlocksExpansion,
@@ -109,6 +116,7 @@ function normalizePreferences(pref?: Partial<Preferences> & { agentModelSelectio
     lastUsedBinary: sanitized.lastUsedBinary ?? defaultPreferences.lastUsedBinary,
     environmentVariables,
     modelRecents,
+    modelThinkingSelections,
     diffViewMode: sanitized.diffViewMode ?? defaultPreferences.diffViewMode,
     toolOutputExpansion: sanitized.toolOutputExpansion ?? defaultPreferences.toolOutputExpansion,
     diagnosticsExpansion: sanitized.diagnosticsExpansion ?? defaultPreferences.diagnosticsExpansion,
@@ -118,6 +126,35 @@ function normalizePreferences(pref?: Partial<Preferences> & { agentModelSelectio
   }
 }
 
+function getModelKey(model: { providerId: string; modelId: string }): string {
+  return `${model.providerId}/${model.modelId}`
+}
+
+function getModelThinkingSelection(model: { providerId: string; modelId: string }): string | undefined {
+  if (!model.providerId || !model.modelId) return undefined
+  return preferences().modelThinkingSelections?.[getModelKey(model)]
+}
+
+function setModelThinkingSelection(model: { providerId: string; modelId: string }, value: string | undefined): void {
+  if (!model.providerId || !model.modelId) return
+  const key = getModelKey(model)
+  const current = preferences().modelThinkingSelections?.[key]
+  if (current === value) return
+
+  updateConfig((draft) => {
+    const selections = { ...(draft.preferences.modelThinkingSelections ?? {}) }
+    if (!value) {
+      delete selections[key]
+    } else {
+      selections[key] = value
+    }
+    draft.preferences = normalizePreferences({
+      ...draft.preferences,
+      modelThinkingSelections: selections,
+    })
+  })
+}
+
 const [internalConfig, setInternalConfig] = createSignal<ConfigData>(buildFallbackConfig())
 
 const config = createMemo<DeepReadonly<ConfigData>>(() => internalConfig())
@@ -527,6 +564,8 @@ export {
   addEnvironmentVariable,
   removeEnvironmentVariable,
   addRecentModelPreference,
+  getModelThinkingSelection,
+  setModelThinkingSelection,
   setAgentModelPreference,
   getAgentModelPreference,
   setDiffViewMode,
@@ -540,4 +579,3 @@ export {
  }
  
 
-

packages/ui/src/stores/session-actions.ts

@@ -1,8 +1,8 @@
 import { resolvePastedPlaceholders } from "../lib/prompt-placeholders"
 import { instances } from "./instances"
 
-import { addRecentModelPreference, setAgentModelPreference } from "./preferences"
-import { sessions, withSession } from "./session-state"
+import { addRecentModelPreference, getModelThinkingSelection, setAgentModelPreference } from "./preferences"
+import { providers, sessions, withSession } from "./session-state"
 import { getDefaultModel, isModelValid } from "./session-models"
 import { updateSessionInfo } from "./message-v2/session-info"
 import { messageStoreBus } from "./message-v2/bus"
@@ -11,6 +11,22 @@ import { requestData } from "../lib/opencode-api"
 
 const log = getLogger("actions")
 
+function getVariantKeysForModel(instanceId: string, model: { providerId: string; modelId: string }): string[] {
+  if (!model.providerId || !model.modelId) return []
+  const instanceProviders = providers().get(instanceId) || []
+  const provider = instanceProviders.find((p) => p.id === model.providerId)
+  const match = provider?.models.find((m) => m.id === model.modelId)
+  return match?.variantKeys ?? []
+}
+
+function getThinkingVariantToSend(instanceId: string, model: { providerId: string; modelId: string }): string | undefined {
+  const selected = getModelThinkingSelection(model)
+  if (!selected) return undefined
+  const keys = getVariantKeysForModel(instanceId, model)
+  if (keys.length === 0) return undefined
+  return keys.includes(selected) ? selected : undefined
+}
+
 const ID_LENGTH = 26
 const BASE62_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
 
@@ -170,6 +186,12 @@ async function sendMessage(
           modelID: session.model.modelId,
         },
       }),
+    ...(session.model.providerId &&
+      session.model.modelId &&
+      (() => {
+        const variant = getThinkingVariantToSend(instanceId, session.model)
+        return variant ? { variant } : {}
+      })()),
   }
 
   log.info("sendMessage", {
@@ -215,6 +237,7 @@ async function executeCustomCommand(
     messageID: string
     agent?: string
     model?: string
+    variant?: string
   } = {
     command: commandName,
     arguments: args,
@@ -227,6 +250,8 @@ async function executeCustomCommand(
 
   if (session.model.providerId && session.model.modelId) {
     body.model = `${session.model.providerId}/${session.model.modelId}`
+    const variant = getThinkingVariantToSend(instanceId, session.model)
+    if (variant) body.variant = variant
   }
 
   await requestData(

packages/ui/src/stores/session-api.ts

@@ -483,6 +483,7 @@ async function fetchProviders(instanceId: string): Promise<void> {
         providerId: provider.id,
         limit: model.limit,
         cost: model.cost,
+        variantKeys: Object.keys(model.variants ?? {}),
       })),
     }))