Add effort level control for Claude sessions

Author: charlesvien

apps/code/src/main/services/agent/schemas.ts

@@ -46,6 +46,7 @@ export const startSessionInput = z.object({
   adapter: z.enum(["claude", "codex"]).optional(),
   additionalDirectories: z.array(z.string()).optional(),
   customInstructions: z.string().max(2000).optional(),
+  effort: z.enum(["low", "medium", "high", "max"]).optional(),
 });
 
 export type StartSessionInput = z.infer<typeof startSessionInput>;

apps/code/src/main/services/agent/service.ts

@@ -200,6 +200,8 @@ interface SessionConfig {
   permissionMode?: string;
   /** Custom instructions injected into the system prompt */
   customInstructions?: string;
+  /** Effort level for Claude sessions */
+  effort?: "low" | "medium" | "high" | "max";
 }
 
 interface ManagedSession {
@@ -632,6 +634,7 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
       additionalDirectories,
       permissionMode,
       customInstructions,
+      effort,
     } = config;
 
     // Preview sessions don't need a real repo — use a temp directory
@@ -783,6 +786,7 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
                 ...(additionalDirectories?.length && {
                   additionalDirectories,
                 }),
+                ...(effort && { effort }),
                 plugins,
               },
             },
@@ -811,6 +815,7 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
             claudeCode: {
               options: {
                 ...(additionalDirectories?.length && { additionalDirectories }),
+                ...(effort && { effort }),
                 plugins,
               },
             },
@@ -1551,6 +1556,7 @@ For git operations while detached:
         "permissionMode" in params ? params.permissionMode : undefined,
       customInstructions:
         "customInstructions" in params ? params.customInstructions : undefined,
+      effort: "effort" in params ? params.effort : undefined,
     };
   }
 

apps/code/src/renderer/features/message-editor/components/EditorToolbar.tsx

@@ -1,5 +1,4 @@
 import { ModelSelector } from "@features/sessions/components/ModelSelector";
-import { ReasoningLevelSelector } from "@features/sessions/components/ReasoningLevelSelector";
 import { Paperclip } from "@phosphor-icons/react";
 import { Flex, IconButton, Tooltip } from "@radix-ui/themes";
 import { useRef } from "react";
@@ -45,7 +44,7 @@ export function EditorToolbar({
   };
 
   return (
-    <Flex align="center" gap="1">
+    <Flex align="center" gap="3">
       <input
         ref={fileInputRef}
         type="file"
@@ -68,14 +67,7 @@ export function EditorToolbar({
         </IconButton>
       </Tooltip>
       {!hideSelectors && (
-        <>
-          <ModelSelector
-            taskId={taskId}
-            adapter={adapter}
-            disabled={disabled}
-          />
-          <ReasoningLevelSelector taskId={taskId} disabled={disabled} />
-        </>
+        <ModelSelector taskId={taskId} adapter={adapter} disabled={disabled} />
       )}
     </Flex>
   );

apps/code/src/renderer/features/sessions/components/ReasoningLevelSelector.tsx

@@ -2,6 +2,7 @@ import { Select, Text } from "@radix-ui/themes";
 import { getSessionService } from "../service/service";
 import {
   flattenSelectOptions,
+  useAdapterForTask,
   useSessionForTask,
   useThoughtLevelConfigOptionForTask,
 } from "../stores/sessionStore";
@@ -17,6 +18,7 @@ export function ReasoningLevelSelector({
 }: ReasoningLevelSelectorProps) {
   const session = useSessionForTask(taskId);
   const thoughtOption = useThoughtLevelConfigOptionForTask(taskId);
+  const adapter = useAdapterForTask(taskId);
 
   if (!thoughtOption) {
     return null;
@@ -57,7 +59,7 @@ export function ReasoningLevelSelector({
         }}
       >
         <Text size="1" style={{ fontFamily: "var(--font-mono)" }}>
-          Reasoning: {activeLabel}
+          {adapter === "codex" ? "Reasoning" : "Effort"}: {activeLabel}
         </Text>
       </Select.Trigger>
       <Select.Content position="popper" sideOffset={4}>

apps/code/src/renderer/features/sessions/service/service.ts

@@ -537,6 +537,7 @@ export class SessionService {
       permissionMode: executionMode,
       adapter,
       customInstructions: startCustomInstructions || undefined,
+      effort: reasoningLevel as "low" | "medium" | "high" | "max" | undefined,
     });
 
     const session = this.createBaseSession(taskRun.id, taskId, taskTitle);

apps/code/src/renderer/features/task-detail/components/TaskInputEditor.tsx

@@ -210,7 +210,7 @@ export const TaskInputEditor = forwardRef<
         </Flex>
 
         <Flex justify="between" align="center" px="3" pb="3">
-          <Flex align="center" gap="1">
+          <Flex align="center" gap="3">
             <EditorToolbar
               disabled={isCreatingTask}
               adapter={adapter}

packages/agent/src/adapters/claude/claude-agent.ts

@@ -558,6 +558,8 @@ export class ClaudeAcpAgent extends BaseAcpAgent {
       const sdkModelId = toSdkModelId(params.value);
       await this.session.query.setModel(sdkModelId);
       this.session.modelId = params.value;
+    } else if (params.configId === "effort") {
+      this.session.effort = params.value as "low" | "medium" | "high" | "max";
     }
 
     this.session.configOptions = this.session.configOptions.map((o) =>
@@ -623,6 +625,12 @@ export class ClaudeAcpAgent extends BaseAcpAgent {
 
     const meta = params._meta as NewSessionMeta | undefined;
     const taskId = meta?.persistence?.taskId;
+    const effort = meta?.claudeCode?.options?.effort as
+      | "low"
+      | "medium"
+      | "high"
+      | "max"
+      | undefined;
 
     // We want to create a new session id unless it is resume,
     // but not resume + forkSession.
@@ -673,6 +681,7 @@ export class ClaudeAcpAgent extends BaseAcpAgent {
       onModeChange: this.createOnModeChange(),
       onProcessSpawned: this.options?.onProcessSpawned,
       onProcessExited: this.options?.onProcessExited,
+      effort,
     });
 
     // Use the same abort controller that buildSessionOptions gave to the query
@@ -693,6 +702,7 @@ export class ClaudeAcpAgent extends BaseAcpAgent {
         cachedReadTokens: 0,
         cachedWriteTokens: 0,
       },
+      effort,
       configOptions: [],
       promptRunning: false,
       pendingMessages: new Map(),
@@ -790,7 +800,11 @@ export class ClaudeAcpAgent extends BaseAcpAgent {
       ),
     };
 
-    const configOptions = this.buildConfigOptions(permissionMode, modelOptions);
+    const configOptions = this.buildConfigOptions(
+      permissionMode,
+      modelOptions,
+      effort ?? "high",
+    );
     session.configOptions = configOptions;
 
     if (!creationOpts.skipBackgroundFetches) {
@@ -844,6 +858,7 @@ export class ClaudeAcpAgent extends BaseAcpAgent {
       currentModelId: string;
       options: SessionConfigSelectOption[];
     },
+    currentEffort: "low" | "medium" | "high" | "max" = "high",
   ): SessionConfigOption[] {
     const modeOptions = getAvailableModes().map((mode) => ({
       value: mode.id,
@@ -871,6 +886,20 @@ export class ClaudeAcpAgent extends BaseAcpAgent {
         category: "model" as SessionConfigOptionCategory,
         description: "Choose which model Claude should use",
       },
+      {
+        id: "effort",
+        name: "Effort",
+        type: "select",
+        currentValue: currentEffort,
+        options: [
+          { value: "low", name: "Low" },
+          { value: "medium", name: "Medium" },
+          { value: "high", name: "High" },
+          { value: "max", name: "Max" },
+        ],
+        category: "thought_level" as SessionConfigOptionCategory,
+        description: "Controls how much effort Claude puts into its response",
+      },
     ];
   }
 

packages/agent/src/adapters/claude/session/options.ts

@@ -43,6 +43,7 @@ export interface BuildOptionsParams {
   onModeChange?: OnModeChange;
   onProcessSpawned?: (info: ProcessSpawnedInfo) => void;
   onProcessExited?: (pid: number) => void;
+  effort?: "low" | "medium" | "high" | "max";
 }
 
 const BRANCH_NAMING_INSTRUCTIONS = `
@@ -295,6 +296,10 @@ export function buildSessionOptions(params: BuildOptionsParams): Options {
     options.additionalDirectories = params.additionalDirectories;
   }
 
+  if (params.effort) {
+    options.effort = params.effort;
+  }
+
   clearStatsigCache();
   return options;
 }

packages/agent/src/adapters/claude/types.ts

@@ -46,6 +46,7 @@ export type Session = BaseSession & {
   taskRunId?: string;
   lastPlanFilePath?: string;
   lastPlanContent?: string;
+  effort?: "low" | "medium" | "high" | "max";
   configOptions: SessionConfigOption[];
   accumulatedUsage: AccumulatedUsage;
   promptRunning: boolean;