diff --git a/apps/server/src/orchestration/Layers/ProviderCommandReactor.test.ts b/apps/server/src/orchestration/Layers/ProviderCommandReactor.test.ts
index 52f1db0dc..36958e9c2 100644
--- a/apps/server/src/orchestration/Layers/ProviderCommandReactor.test.ts
+++ b/apps/server/src/orchestration/Layers/ProviderCommandReactor.test.ts
@@ -351,6 +351,56 @@ describe("ProviderCommandReactor", () => {
     });
   });
 
+  it("forwards claude effort options through session start and turn send", async () => {
+    const harness = await createHarness();
+    const now = new Date().toISOString();
+
+    await Effect.runPromise(
+      harness.engine.dispatch({
+        type: "thread.turn.start",
+        commandId: CommandId.makeUnsafe("cmd-turn-start-claude-effort"),
+        threadId: ThreadId.makeUnsafe("thread-1"),
+        message: {
+          messageId: asMessageId("user-message-claude-effort"),
+          role: "user",
+          text: "hello with effort",
+          attachments: [],
+        },
+        provider: "claudeAgent",
+        model: "claude-sonnet-4-6",
+        modelOptions: {
+          claudeAgent: {
+            effort: "max",
+          },
+        },
+        interactionMode: DEFAULT_PROVIDER_INTERACTION_MODE,
+        runtimeMode: "approval-required",
+        createdAt: now,
+      }),
+    );
+
+    await waitFor(() => harness.startSession.mock.calls.length === 1);
+    await waitFor(() => harness.sendTurn.mock.calls.length === 1);
+    expect(harness.startSession.mock.calls[0]?.[1]).toMatchObject({
+      provider: "claudeAgent",
+      model: "claude-sonnet-4-6",
+      modelOptions: {
+        claudeAgent: {
+          effort: "max",
+        },
+      },
+    });
+    expect(harness.sendTurn.mock.calls[0]?.[0]).toMatchObject({
+      threadId: ThreadId.makeUnsafe("thread-1"),
+      model: "claude-sonnet-4-6",
+      modelOptions: {
+        claudeAgent: {
+          effort: "max",
+        },
+      },
+    });
+  });
+
   it("forwards plan interaction mode to the provider turn request", async () => {
     const harness = await createHarness();
     const now = new Date().toISOString();
@@ -531,6 +581,73 @@ describe("ProviderCommandReactor", () => {
     expect(harness.stopSession.mock.calls.length).toBe(0);
   });
 
+  it("restarts claude sessions when claude effort changes", async () => {
+    const harness = await createHarness();
+    const now = new Date().toISOString();
+
+    await Effect.runPromise(
+      harness.engine.dispatch({
+        type: "thread.turn.start",
+        commandId: CommandId.makeUnsafe("cmd-turn-start-claude-effort-1"),
+        threadId: ThreadId.makeUnsafe("thread-1"),
+        message: {
+          messageId: asMessageId("user-message-claude-effort-1"),
+          role: "user",
+          text: "first claude turn",
+          attachments: [],
+        },
+        provider: "claudeAgent",
+        model: "claude-sonnet-4-6",
+        modelOptions: {
+          claudeAgent: {
+            effort: "medium",
+          },
+        },
+        interactionMode: DEFAULT_PROVIDER_INTERACTION_MODE,
+        runtimeMode: "approval-required",
+        createdAt: now,
+      }),
+    );
+
+    await waitFor(() => harness.startSession.mock.calls.length === 1);
+    await waitFor(() => harness.sendTurn.mock.calls.length === 1);
+
+    await Effect.runPromise(
+      harness.engine.dispatch({
+        type: "thread.turn.start",
+        commandId: CommandId.makeUnsafe("cmd-turn-start-claude-effort-2"),
+        threadId: ThreadId.makeUnsafe("thread-1"),
+        message: {
+          messageId: asMessageId("user-message-claude-effort-2"),
+          role: "user",
+          text: "second claude turn",
+          attachments: [],
+        },
+        provider: "claudeAgent",
+        model: "claude-sonnet-4-6",
+        modelOptions: {
+          claudeAgent: {
+            effort: "max",
+          },
+        },
+        interactionMode: DEFAULT_PROVIDER_INTERACTION_MODE,
+        runtimeMode: "approval-required",
+        createdAt: now,
+      }),
+    );
+
+    await waitFor(() => harness.startSession.mock.calls.length === 2);
+    await waitFor(() => harness.sendTurn.mock.calls.length === 2);
+    expect(harness.startSession.mock.calls[1]?.[1]).toMatchObject({
+      provider: "claudeAgent",
+      modelOptions: {
+        claudeAgent: {
+          effort: "max",
+        },
+      },
+    });
+  });
+
   it("restarts the provider session when runtime mode is updated on the thread", async () => {
     const harness = await createHarness();
     const now = new Date().toISOString();
diff --git a/apps/server/src/orchestration/Layers/ProviderCommandReactor.ts b/apps/server/src/orchestration/Layers/ProviderCommandReactor.ts
index 38d0b7bbd..bbf3bef27 100644
--- a/apps/server/src/orchestration/Layers/ProviderCommandReactor.ts
+++ b/apps/server/src/orchestration/Layers/ProviderCommandReactor.ts
@@ -75,6 +75,11 @@ const DEFAULT_RUNTIME_MODE: RuntimeMode = "full-access";
 const WORKTREE_BRANCH_PREFIX = "t3code";
 const TEMP_WORKTREE_BRANCH_PATTERN = new RegExp(`^${WORKTREE_BRANCH_PREFIX}\\/[0-9a-f]{8}$`);
 
+const sameModelOptions = (
+  left: ProviderModelOptions | undefined,
+  right: ProviderModelOptions | undefined,
+): boolean => JSON.stringify(left ?? null) === JSON.stringify(right ?? null);
+
 function isUnknownPendingApprovalRequestError(cause: Cause.Cause<ProviderServiceError>): boolean {
   const error = Cause.squash(cause);
   if (Schema.is(ProviderAdapterRequestError)(error)) {
@@ -137,6 +142,7 @@ const make = Effect.gen(function* () {
     );
 
   const threadProviderOptions = new Map<string, ProviderStartOptions>();
+  const threadModelOptions = new Map<string, ProviderModelOptions>();
 
   const appendProviderFailureActivity = (input: {
     readonly threadId: ThreadId;
@@ -289,13 +295,23 @@ const make = Effect.gen(function* () {
           : (yield* providerService.getCapabilities(currentProvider)).sessionModelSwitch;
       const modelChanged = options?.model !== undefined && options.model !== activeSession?.model;
       const shouldRestartForModelChange = modelChanged && sessionModelSwitch === "restart-session";
+      const previousModelOptions = threadModelOptions.get(threadId);
+      const shouldRestartForModelOptionsChange =
+        currentProvider === "claudeAgent" &&
+        options?.modelOptions !== undefined &&
+        !sameModelOptions(previousModelOptions, options.modelOptions);
 
-      if (!runtimeModeChanged && !providerChanged && !shouldRestartForModelChange) {
+      if (
+        !runtimeModeChanged &&
+        !providerChanged &&
+        !shouldRestartForModelChange &&
+        !shouldRestartForModelOptionsChange
+      ) {
         return existingSessionThreadId;
       }
 
       const resumeCursor =
-        providerChanged || shouldRestartForModelChange
+        providerChanged || shouldRestartForModelChange || shouldRestartForModelOptionsChange
           ? undefined
           : (activeSession?.resumeCursor ?? undefined);
       yield* Effect.logInfo("provider command reactor restarting provider session", {
@@ -309,6 +325,7 @@ const make = Effect.gen(function* () {
         providerChanged,
         modelChanged,
         shouldRestartForModelChange,
+        shouldRestartForModelOptionsChange,
         hasResumeCursor: resumeCursor !== undefined,
       });
       const restartedSession = yield* startProviderSession({
@@ -348,15 +365,18 @@ const make = Effect.gen(function* () {
     if (!thread) {
       return;
     }
-    if (input.providerOptions !== undefined) {
-      threadProviderOptions.set(input.threadId, input.providerOptions);
-    }
     yield* ensureSessionForThread(input.threadId, input.createdAt, {
       ...(input.provider !== undefined ? { provider: input.provider } : {}),
       ...(input.model !== undefined ? { model: input.model } : {}),
       ...(input.modelOptions !== undefined ? { modelOptions: input.modelOptions } : {}),
       ...(input.providerOptions !== undefined ? { providerOptions: input.providerOptions } : {}),
     });
+    if (input.providerOptions !== undefined) {
+      threadProviderOptions.set(input.threadId, input.providerOptions);
+    }
+    if (input.modelOptions !== undefined) {
+      threadModelOptions.set(input.threadId, input.modelOptions);
+    }
     const normalizedInput = toNonEmptyProviderInput(input.messageText);
     const normalizedAttachments = input.attachments ?? [];
     const activeSession = yield* providerService
@@ -657,13 +677,13 @@ const make = Effect.gen(function* () {
             return;
           }
           const cachedProviderOptions = threadProviderOptions.get(event.payload.threadId);
-          yield* ensureSessionForThread(
-            event.payload.threadId,
-            event.occurredAt,
-            cachedProviderOptions !== undefined
+          const cachedModelOptions = threadModelOptions.get(event.payload.threadId);
+          yield* ensureSessionForThread(event.payload.threadId, event.occurredAt, {
+            ...(cachedProviderOptions !== undefined
               ? { providerOptions: cachedProviderOptions }
-              : undefined,
-          );
+              : {}),
+            ...(cachedModelOptions !== undefined ? { modelOptions: cachedModelOptions } : {}),
+          });
           return;
         }
         case "thread.turn-start-requested":
diff --git a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts
index 2592287f7..84276011a 100644
--- a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts
+++ b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts
@@ -1412,6 +1412,7 @@ describe("ProviderRuntimeIngestion", () => {
       payload: {
         taskId: "turn-task-1",
         description: "Comparing the desktop rollout chunks to the app-server stream.",
+        summary: "Code reviewer is validating the desktop rollout chunks.",
       },
     });
 
@@ -1474,8 +1475,9 @@ describe("ProviderRuntimeIngestion", () => {
     expect(started?.kind).toBe("task.started");
     expect(started?.summary).toBe("Plan task started");
     expect(progress?.kind).toBe("task.progress");
-    expect(progressPayload?.detail).toBe(
-      "Comparing the desktop rollout chunks to the app-server stream.",
+    expect(progressPayload?.detail).toBe("Code reviewer is validating the desktop rollout chunks.");
+    expect(progressPayload?.summary).toBe(
+      "Code reviewer is validating the desktop rollout chunks.",
     );
     expect(completed?.kind).toBe("task.completed");
     expect(completedPayload?.detail).toBe("<proposed_plan>\n# Plan title\n</proposed_plan>");
diff --git a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts
index 417e93c8d..49970be92 100644
--- a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts
+++ b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts
@@ -370,7 +370,8 @@ function runtimeEventToActivities(
           summary: "Reasoning update",
           payload: {
             taskId: event.payload.taskId,
-            detail: truncateDetail(event.payload.description),
+            detail: truncateDetail(event.payload.summary ?? event.payload.description),
+            ...(event.payload.summary ? { summary: truncateDetail(event.payload.summary) } : {}),
             ...(event.payload.lastToolName ? { lastToolName: event.payload.lastToolName } : {}),
             ...(event.payload.usage !== undefined ? { usage: event.payload.usage } : {}),
           },
diff --git a/apps/server/src/provider/Layers/ClaudeAdapter.test.ts b/apps/server/src/provider/Layers/ClaudeAdapter.test.ts
index 5792c5307..c4ea1333b 100644
--- a/apps/server/src/provider/Layers/ClaudeAdapter.test.ts
+++ b/apps/server/src/provider/Layers/ClaudeAdapter.test.ts
@@ -156,6 +156,28 @@ function makeDeterministicRandomService(seed = 0x1234_5678): {
   };
 }
 
+async function readFirstPromptText(
+  input:
+    | {
+        readonly prompt: AsyncIterable<SDKUserMessage>;
+      }
+    | undefined,
+): Promise<string | undefined> {
+  const iterator = input?.prompt[Symbol.asyncIterator]();
+  if (!iterator) {
+    return undefined;
+  }
+  const next = await iterator.next();
+  if (next.done) {
+    return undefined;
+  }
+  const content = next.value.message.content[0];
+  if (!content || content.type !== "text") {
+    return undefined;
+  }
+  return content.text;
+}
+
 const THREAD_ID = ThreadId.makeUnsafe("thread-claude-1");
 const RESUME_THREAD_ID = ThreadId.makeUnsafe("thread-claude-resume");
 
@@ -229,6 +251,65 @@ describe("ClaudeAdapterLive", () => {
     );
   });
 
+  it.effect("forwards claude effort levels into query options", () => {
+    const harness = makeHarness();
+    return Effect.gen(function* () {
+      const adapter = yield* ClaudeAdapter;
+      yield* adapter.startSession({
+        threadId: THREAD_ID,
+        provider: "claudeAgent",
+        runtimeMode: "full-access",
+        modelOptions: {
+          claudeAgent: {
+            effort: "max",
+          },
+        },
+      });
+
+      const createInput = harness.getLastCreateQueryInput();
+      assert.equal(createInput?.options.effort, "max");
+    }).pipe(
+      Effect.provideService(Random.Random, makeDeterministicRandomService()),
+      Effect.provide(harness.layer),
+    );
+  });
+
+  it.effect("maps ultrathink to max effort and prefixes the prompt", () => {
+    const harness = makeHarness();
+    return Effect.gen(function* () {
+      const adapter = yield* ClaudeAdapter;
+      const session = yield* adapter.startSession({
+        threadId: THREAD_ID,
+        provider: "claudeAgent",
+        runtimeMode: "full-access",
+        modelOptions: {
+          claudeAgent: {
+            effort: "ultrathink",
+          },
+        },
+      });
+
+      yield* adapter.sendTurn({
+        threadId: session.threadId,
+        input: "Investigate the edge cases",
+        attachments: [],
+        modelOptions: {
+          claudeAgent: {
+            effort: "ultrathink",
+          },
+        },
+      });
+
+      const createInput = harness.getLastCreateQueryInput();
+      assert.equal(createInput?.options.effort, "max");
+      const promptText = yield* Effect.promise(() => readFirstPromptText(createInput));
+      assert.equal(promptText, "Ultrathink:\nInvestigate the edge cases");
+    }).pipe(
+      Effect.provideService(Random.Random, makeDeterministicRandomService()),
+      Effect.provide(harness.layer),
+    );
+  });
+
   it.effect("maps Claude stream/runtime messages to canonical provider runtime events", () => {
     const harness = makeHarness();
     return Effect.gen(function* () {
@@ -582,6 +663,129 @@ describe("ClaudeAdapterLive", () => {
     );
   });
 
+  it.effect("classifies Claude Task tool invocations as collaboration agent work", () => {
+    const harness = makeHarness();
+    return Effect.gen(function* () {
+      const adapter = yield* ClaudeAdapter;
+
+      const runtimeEventsFiber = yield* Stream.take(adapter.streamEvents, 8).pipe(
+        Stream.runCollect,
+        Effect.forkChild,
+      );
+
+      const session = yield* adapter.startSession({
+        threadId: THREAD_ID,
+        provider: "claudeAgent",
+        runtimeMode: "full-access",
+      });
+
+      yield* adapter.sendTurn({
+        threadId: session.threadId,
+        input: "delegate this",
+        attachments: [],
+      });
+
+      harness.query.emit({
+        type: "stream_event",
+        session_id: "sdk-session-task",
+        uuid: "stream-task-1",
+        parent_tool_use_id: null,
+        event: {
+          type: "content_block_start",
+          index: 0,
+          content_block: {
+            type: "tool_use",
+            id: "tool-task-1",
+            name: "Task",
+            input: {
+              description: "Review the database layer",
+              prompt: "Audit the SQL changes",
+              subagent_type: "code-reviewer",
+            },
+          },
+        },
+      } as unknown as SDKMessage);
+
+      harness.query.emit({
+        type: "assistant",
+        session_id: "sdk-session-task",
+        uuid: "assistant-task-1",
+        parent_tool_use_id: null,
+        message: {
+          id: "assistant-message-task-1",
+          content: [{ type: "text", text: "Delegated" }],
+        },
+      } as unknown as SDKMessage);
+
+      harness.query.emit({
+        type: "result",
+        subtype: "success",
+        is_error: false,
+        errors: [],
+        session_id: "sdk-session-task",
+        uuid: "result-task-1",
+      } as unknown as SDKMessage);
+
+      const runtimeEvents = Array.from(yield* Fiber.join(runtimeEventsFiber));
+      const toolStarted = runtimeEvents.find((event) => event.type === "item.started");
+      assert.equal(toolStarted?.type, "item.started");
+      if (toolStarted?.type === "item.started") {
+        assert.equal(toolStarted.payload.itemType, "collab_agent_tool_call");
+        assert.equal(toolStarted.payload.title, "Subagent task");
+      }
+    }).pipe(
+      Effect.provideService(Random.Random, makeDeterministicRandomService()),
+      Effect.provide(harness.layer),
+    );
+  });
+
+  it.effect("forwards Claude task progress summaries for subagent updates", () => {
+    const harness = makeHarness();
+    return Effect.gen(function* () {
+      const adapter = yield* ClaudeAdapter;
+
+      const runtimeEventsFiber = yield* Stream.take(adapter.streamEvents, 5).pipe(
+        Stream.runCollect,
+        Effect.forkChild,
+      );
+
+      yield* adapter.startSession({
+        threadId: THREAD_ID,
+        provider: "claudeAgent",
+        runtimeMode: "full-access",
+      });
+
+      harness.query.emit({
+        type: "system",
+        subtype: "task_progress",
+        task_id: "task-subagent-1",
+        description: "Running background teammate",
+        summary: "Code reviewer checked the migration edge cases.",
+        usage: {
+          total_tokens: 123,
+          tool_uses: 4,
+          duration_ms: 987,
+        },
+        session_id: "sdk-session-task-summary",
+        uuid: "task-progress-1",
+      } as unknown as SDKMessage);
+
+      const runtimeEvents = Array.from(yield* Fiber.join(runtimeEventsFiber));
+      const progressEvent = runtimeEvents.find((event) => event.type === "task.progress");
+      assert.equal(progressEvent?.type, "task.progress");
+      if (progressEvent?.type === "task.progress") {
+        assert.equal(
+          progressEvent.payload.summary,
+          "Code reviewer checked the migration edge cases.",
+        );
+        assert.equal(progressEvent.payload.description, "Running background teammate");
+      }
+    }).pipe(
+      Effect.provideService(Random.Random, makeDeterministicRandomService()),
+      Effect.provide(harness.layer),
+    );
+  });
+
   it.effect(
     "emits completion only after turn result when assistant frames arrive before deltas",
     () => {
diff --git a/apps/server/src/provider/Layers/ClaudeAdapter.ts b/apps/server/src/provider/Layers/ClaudeAdapter.ts
index 887a2f2de..c8239bb48 100644
--- a/apps/server/src/provider/Layers/ClaudeAdapter.ts
+++ b/apps/server/src/provider/Layers/ClaudeAdapter.ts
@@ -37,6 +37,7 @@ import {
   TurnId,
   type UserInputQuestion,
 } from "@t3tools/contracts";
+import { applyClaudePromptEffortPrefix, getEffectiveClaudeCodeEffort } from "@t3tools/shared/model";
 import { Cause, DateTime, Deferred, Effect, Layer, Queue, Random, Ref, Stream } from "effect";
 
 import {
@@ -233,6 +234,14 @@ function classifyToolItemType(toolName: string): CanonicalItemType {
   if (normalized.includes("agent")) {
     return "collab_agent_tool_call";
   }
+  if (
+    normalized === "task" ||
+    normalized === "agent" ||
+    normalized.includes("subagent") ||
+    normalized.includes("sub-agent")
+  ) {
+    return "collab_agent_tool_call";
+  }
   if (
     normalized.includes("bash") ||
     normalized.includes("command") ||
@@ -311,7 +320,7 @@ function titleForTool(itemType: CanonicalItemType): string {
     case "mcp_tool_call":
       return "MCP tool call";
     case "collab_agent_tool_call":
-      return "Agent task";
+      return "Subagent task";
     case "web_search":
       return "Web search";
     case "image_view":
@@ -338,7 +347,10 @@ function buildUserMessage(input: ProviderSendTurnInput): SDKUserMessage {
     }
   }
 
-  const text = fragments.join("\n\n");
+  const text = applyClaudePromptEffortPrefix(
+    fragments.join("\n\n"),
+    input.modelOptions?.claudeAgent?.effort ?? null,
+  );
 
   return {
     type: "user",
@@ -1085,6 +1097,8 @@ function makeClaudeAdapter(options?: ClaudeAdapterLiveOptions) {
           });
           context.inFlightTools.delete(index);
         }
+        // Clear any remaining stale entries (e.g. from interrupted content blocks)
+        context.inFlightTools.clear();
 
         for (const blockIndex of turnState.assistantTextBlockOrder) {
           yield* completeAssistantTextBlock(context, blockIndex, {
@@ -1465,6 +1479,46 @@ function makeClaudeAdapter(options?: ClaudeAdapterLiveOptions) {
           return;
         }
 
+        // Auto-start a synthetic turn for assistant messages that arrive without
+        // an active turn (e.g., background agent/subagent responses between user prompts).
+        if (!context.turnState) {
+          const turnId = TurnId.makeUnsafe(yield* Random.nextUUIDv4);
+          const startedAt = yield* nowIso;
+          context.turnState = {
+            turnId,
+            startedAt,
+            items: [],
+            assistantTextBlocks: new Map(),
+            assistantTextBlockOrder: [],
+            nextSyntheticAssistantBlockIndex: -1,
+          };
+          context.session = {
+            ...context.session,
+            status: "running",
+            activeTurnId: turnId,
+            updatedAt: startedAt,
+          };
+          const turnStartedStamp = yield* makeEventStamp();
+          yield* offerRuntimeEvent({
+            type: "turn.started",
+            eventId: turnStartedStamp.eventId,
+            provider: PROVIDER,
+            createdAt: turnStartedStamp.createdAt,
+            threadId: context.session.threadId,
+            turnId,
+            payload: {},
+            providerRefs: {
+              ...nativeProviderRefs(context),
+              providerTurnId: turnId,
+            },
+            raw: {
+              source: "claude.sdk.message",
+              method: "claude/synthetic-turn-start",
+              payload: {},
+            },
+          });
+        }
+
         if (context.turnState) {
           context.turnState.items.push(message.message);
           yield* backfillAssistantTextBlocksFromSnapshot(context, message);
@@ -1604,6 +1658,7 @@ function makeClaudeAdapter(options?: ClaudeAdapterLiveOptions) {
               payload: {
                 taskId: RuntimeTaskId.makeUnsafe(message.task_id),
                 description: message.description,
+                ...(message.summary ? { summary: message.summary } : {}),
                 ...(message.usage ? { usage: message.usage } : {}),
                 ...(message.last_tool_name ? { lastToolName: message.last_tool_name } : {}),
               },
@@ -2138,6 +2193,8 @@ function makeClaudeAdapter(options?: ClaudeAdapterLiveOptions) {
           );
 
         const providerOptions = input.providerOptions?.claudeAgent;
+        const effort = input.modelOptions?.claudeAgent?.effort;
+        const effectiveEffort = getEffectiveClaudeCodeEffort(effort);
         const permissionMode =
           toPermissionMode(providerOptions?.permissionMode) ??
           (input.runtimeMode === "full-access" ? "bypassPermissions" : undefined);
@@ -2148,6 +2205,7 @@ function makeClaudeAdapter(options?: ClaudeAdapterLiveOptions) {
           ...(providerOptions?.binaryPath
             ? { pathToClaudeCodeExecutable: providerOptions.binaryPath }
             : {}),
+          ...(effectiveEffort ? { effort: effectiveEffort } : {}),
           ...(permissionMode ? { permissionMode } : {}),
           ...(permissionMode === "bypassPermissions"
             ? { allowDangerouslySkipPermissions: true }
@@ -2239,6 +2297,7 @@ function makeClaudeAdapter(options?: ClaudeAdapterLiveOptions) {
             config: {
               ...(input.model ? { model: input.model } : {}),
               ...(input.cwd ? { cwd: input.cwd } : {}),
+              ...(effectiveEffort ? { effort: effectiveEffort } : {}),
               ...(permissionMode ? { permissionMode } : {}),
               ...(providerOptions?.maxThinkingTokens !== undefined
                 ? { maxThinkingTokens: providerOptions.maxThinkingTokens }
@@ -2273,11 +2332,9 @@ function makeClaudeAdapter(options?: ClaudeAdapterLiveOptions) {
         const context = yield* requireSession(input.threadId);
 
         if (context.turnState) {
-          return yield* new ProviderAdapterValidationError({
-            provider: PROVIDER,
-            operation: "sendTurn",
-            issue: `Thread '${input.threadId}' already has an active turn '${context.turnState.turnId}'.`,
-          });
+          // Auto-close a stale synthetic turn (from background agent responses
+          // between user prompts) to prevent blocking the user's next turn.
+          yield* completeTurn(context, "completed");
         }
 
         if (input.model) {
diff --git a/apps/server/src/provider/Layers/ProviderService.test.ts b/apps/server/src/provider/Layers/ProviderService.test.ts
index 08c532062..287228751 100644
--- a/apps/server/src/provider/Layers/ProviderService.test.ts
+++ b/apps/server/src/provider/Layers/ProviderService.test.ts
@@ -600,6 +600,58 @@ routing.layer("ProviderServiceLive routing", (it) => {
     }),
   );
 
+  it.effect("recovers stale claudeAgent sessions for sendTurn using persisted cwd", () =>
+    Effect.gen(function* () {
+      const provider = yield* ProviderService;
+
+      const initial = yield* provider.startSession(asThreadId("thread-claude-send-turn"), {
+        provider: "claudeAgent",
+        threadId: asThreadId("thread-claude-send-turn"),
+        cwd: "/tmp/project-claude-send-turn",
+        modelOptions: {
+          claudeAgent: {
+            effort: "max",
+          },
+        },
+        runtimeMode: "full-access",
+      });
+
+      yield* routing.claude.stopAll();
+      routing.claude.startSession.mockClear();
+      routing.claude.sendTurn.mockClear();
+
+      yield* provider.sendTurn({
+        threadId: initial.threadId,
+        input: "resume with claude",
+        attachments: [],
+      });
+
+      assert.equal(routing.claude.startSession.mock.calls.length, 1);
+      const resumedStartInput = routing.claude.startSession.mock.calls[0]?.[0];
+      assert.equal(typeof resumedStartInput === "object" && resumedStartInput !== null, true);
+      if (resumedStartInput && typeof resumedStartInput === "object") {
+        const startPayload = resumedStartInput as {
+          provider?: string;
+          cwd?: string;
+          modelOptions?: unknown;
+          resumeCursor?: unknown;
+          threadId?: string;
+        };
+        assert.equal(startPayload.provider, "claudeAgent");
+        assert.equal(startPayload.cwd, "/tmp/project-claude-send-turn");
+        assert.deepEqual(startPayload.modelOptions, {
+          claudeAgent: {
+            effort: "max",
+          },
+        });
+        assert.deepEqual(startPayload.resumeCursor, initial.resumeCursor);
+        assert.equal(startPayload.threadId, initial.threadId);
+      }
+      assert.equal(routing.claude.sendTurn.mock.calls.length, 1);
+    }),
+  );
+
+
   it.effect("lists no sessions after adapter runtime clears", () =>
     Effect.gen(function* () {
       const provider = yield* ProviderService;
diff --git a/apps/server/src/provider/Layers/ProviderService.ts b/apps/server/src/provider/Layers/ProviderService.ts
index 8e3bc7204..0a250f965 100644
--- a/apps/server/src/provider/Layers/ProviderService.ts
+++ b/apps/server/src/provider/Layers/ProviderService.ts
@@ -88,17 +88,29 @@ function toRuntimeStatus(session: ProviderSession): "starting" | "running" | "st
 
 function toRuntimePayloadFromSession(
   session: ProviderSession,
-  extra?: { readonly providerOptions?: unknown },
+  extra?: { readonly modelOptions?: unknown; readonly providerOptions?: unknown },
 ): Record<string, unknown> {
   return {
     cwd: session.cwd ?? null,
     model: session.model ?? null,
     activeTurnId: session.activeTurnId ?? null,
     lastError: session.lastError ?? null,
+    ...(extra?.modelOptions !== undefined ? { modelOptions: extra.modelOptions } : {}),
     ...(extra?.providerOptions !== undefined ? { providerOptions: extra.providerOptions } : {}),
   };
 }
 
+function readPersistedModelOptions(
+  runtimePayload: ProviderRuntimeBinding["runtimePayload"],
+): Record<string, unknown> | undefined {
+  if (!runtimePayload || typeof runtimePayload !== "object" || Array.isArray(runtimePayload)) {
+    return undefined;
+  }
+  const raw = "modelOptions" in runtimePayload ? runtimePayload.modelOptions : undefined;
+  if (!raw || typeof raw !== "object" || Array.isArray(raw)) return undefined;
+  return raw as Record<string, unknown>;
+}
+
 function readPersistedProviderOptions(
   runtimePayload: ProviderRuntimeBinding["runtimePayload"],
 ): Record<string, unknown> | undefined {
@@ -150,7 +162,7 @@ const makeProviderService = (options?: ProviderServiceLiveOptions) =>
     const upsertSessionBinding = (
       session: ProviderSession,
       threadId: ThreadId,
-      extra?: { readonly providerOptions?: unknown },
+      extra?: { readonly modelOptions?: unknown; readonly providerOptions?: unknown },
     ) =>
       directory.upsert({
         threadId,
@@ -213,12 +225,14 @@ const makeProviderService = (options?: ProviderServiceLiveOptions) =>
         }
 
         const persistedCwd = readPersistedCwd(input.binding.runtimePayload);
+        const persistedModelOptions = readPersistedModelOptions(input.binding.runtimePayload);
         const persistedProviderOptions = readPersistedProviderOptions(input.binding.runtimePayload);
 
         const resumed = yield* adapter.startSession({
           threadId: input.binding.threadId,
           provider: input.binding.provider,
           ...(persistedCwd ? { cwd: persistedCwd } : {}),
+          ...(persistedModelOptions ? { modelOptions: persistedModelOptions } : {}),
           ...(persistedProviderOptions ? { providerOptions: persistedProviderOptions } : {}),
           ...(hasResumeCursor ? { resumeCursor: input.binding.resumeCursor } : {}),
           runtimeMode: input.binding.runtimeMode ?? "full-access",
@@ -292,6 +306,7 @@ const makeProviderService = (options?: ProviderServiceLiveOptions) =>
         }
 
         yield* upsertSessionBinding(session, threadId, {
+          modelOptions: input.modelOptions,
           providerOptions: input.providerOptions,
         });
         yield* analytics.record("provider.session.started", {
diff --git a/apps/server/src/provider/Services/ProviderHealth.ts b/apps/server/src/provider/Services/ProviderHealth.ts
index 318d7e18d..ec3b2d318 100644
--- a/apps/server/src/provider/Services/ProviderHealth.ts
+++ b/apps/server/src/provider/Services/ProviderHealth.ts
@@ -1,8 +1,8 @@
 /**
  * ProviderHealth - Provider readiness snapshot service.
  *
- * Owns startup-time provider health checks (install/auth reachability) and
- * exposes the cached results to transport layers.
+ * Owns provider health checks (install/auth reachability) and exposes the
+ * latest results to transport layers.
  *
  * @module ProviderHealth
  */
@@ -12,7 +12,7 @@ import type { Effect } from "effect";
 
 export interface ProviderHealthShape {
   /**
-   * Read provider health statuses computed at server startup.
+   * Read the latest provider health statuses.
    */
   readonly getStatuses: Effect.Effect<ReadonlyArray<ServerProviderStatus>>;
 }
diff --git a/apps/web/src/components/ChatView.tsx b/apps/web/src/components/ChatView.tsx
index f71a2f3f0..937d162cc 100644
--- a/apps/web/src/components/ChatView.tsx
+++ b/apps/web/src/components/ChatView.tsx
@@ -1,9 +1,9 @@
 import {
   type ApprovalRequestId,
   DEFAULT_MODEL_BY_PROVIDER,
+  type ClaudeCodeEffort,
   type EditorId,
   type KeybindingCommand,
-  type CodexReasoningEffort,
   type MessageId,
   type ProjectId,
   type ProjectEntry,
@@ -15,6 +15,7 @@ import {
   type ProviderApprovalDecision,
   type ServerProviderStatus,
   type ProviderKind,
+  type ProviderReasoningEffort,
   type ThreadId,
   type TurnId,
   OrchestrationThreadActivity,
@@ -22,10 +23,12 @@ import {
   ProviderInteractionMode,
 } from "@t3tools/contracts";
 import {
+  applyClaudePromptEffortPrefix,
   getDefaultModel,
   getDefaultReasoningEffort,
   getReasoningEffortOptions,
   normalizeModelSlug,
+  resolveReasoningEffortForProvider,
   resolveModelSlugForProvider,
 } from "@t3tools/shared/model";
 import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState } from "react";
@@ -137,7 +140,7 @@ import { buildExpandedImagePreview, ExpandedImagePreview } from "./chat/Expanded
 import { AVAILABLE_PROVIDER_OPTIONS, ProviderModelPicker } from "./chat/ProviderModelPicker";
 import { ComposerCommandItem, ComposerCommandMenu } from "./chat/ComposerCommandMenu";
 import { ComposerPendingApprovalActions } from "./chat/ComposerPendingApprovalActions";
-import { CodexTraitsPicker } from "./chat/CodexTraitsPicker";
+import { ProviderTraitsPicker } from "./chat/CodexTraitsPicker";
 import { CompactComposerControlsMenu } from "./chat/CompactComposerControlsMenu";
 import { ComposerPendingApprovalPanel } from "./chat/ComposerPendingApprovalPanel";
 import { ComposerPendingUserInputPanel } from "./chat/ComposerPendingUserInputPanel";
@@ -170,6 +173,17 @@ const EMPTY_PROJECT_ENTRIES: ProjectEntry[] = [];
 const EMPTY_AVAILABLE_EDITORS: EditorId[] = [];
 const EMPTY_PROVIDER_STATUSES: ServerProviderStatus[] = [];
 const EMPTY_PENDING_USER_INPUT_ANSWERS: Record<string, PendingUserInputDraftAnswer> = {};
+
+function formatOutgoingPrompt(params: {
+  provider: ProviderKind;
+  effort: ProviderReasoningEffort | null;
+  text: string;
+}): string {
+  if (params.provider !== "claudeAgent") {
+    return params.text;
+  }
+  return applyClaudePromptEffortPrefix(params.text, params.effort as ClaudeCodeEffort | null);
+}
 const COMPOSER_PATH_QUERY_DEBOUNCE_MS = 120;
 const SCRIPT_TERMINAL_COLS = 120;
 const SCRIPT_TERMINAL_ROWS = 30;
@@ -521,19 +535,45 @@ export default function ChatView({ threadId }: ChatViewProps) {
   }, [baseThreadModel, composerDraft.model, customModelsForSelectedProvider, selectedProvider]);
   const reasoningOptions = getReasoningEffortOptions(selectedProvider);
   const supportsReasoningEffort = reasoningOptions.length > 0;
-  const selectedEffort = composerDraft.effort ?? getDefaultReasoningEffort(selectedProvider);
+  const selectedCodexEffort =
+    selectedProvider === "codex"
+      ? (resolveReasoningEffortForProvider("codex", composerDraft.effort) ??
+        getDefaultReasoningEffort("codex"))
+      : null;
+  const selectedClaudeEffort =
+    selectedProvider === "claudeAgent"
+      ? (resolveReasoningEffortForProvider("claudeAgent", composerDraft.effort) ??
+        getDefaultReasoningEffort("claudeAgent"))
+      : null;
+  const selectedEffort = selectedCodexEffort ?? selectedClaudeEffort;
   const selectedCodexFastModeEnabled =
     selectedProvider === "codex" ? composerDraft.codexFastMode : false;
+  const isClaudeUltrathink = selectedClaudeEffort === "ultrathink";
   const selectedModelOptionsForDispatch = useMemo(() => {
-    if (selectedProvider !== "codex") {
-      return undefined;
+    if (selectedProvider === "codex") {
+      const codexOptions = {
+        ...(supportsReasoningEffort && selectedCodexEffort
+          ? { reasoningEffort: selectedCodexEffort }
+          : {}),
+        ...(selectedCodexFastModeEnabled ? { fastMode: true } : {}),
+      };
+      return Object.keys(codexOptions).length > 0 ? { codex: codexOptions } : undefined;
     }
-    const codexOptions = {
-      ...(supportsReasoningEffort && selectedEffort ? { reasoningEffort: selectedEffort } : {}),
-      ...(selectedCodexFastModeEnabled ? { fastMode: true } : {}),
-    };
-    return Object.keys(codexOptions).length > 0 ? { codex: codexOptions } : undefined;
-  }, [selectedCodexFastModeEnabled, selectedEffort, selectedProvider, supportsReasoningEffort]);
+    if (selectedProvider === "claudeAgent" && selectedClaudeEffort) {
+      return {
+        claudeAgent: {
+          effort: selectedClaudeEffort,
+        },
+      };
+    }
+    return undefined;
+  }, [
+    selectedClaudeEffort,
+    selectedCodexEffort,
+    selectedCodexFastModeEnabled,
+    selectedProvider,
+    supportsReasoningEffort,
+  ]);
   const providerOptionsForDispatch = useMemo(() => {
     if (!settings.codexBinaryPath && !settings.codexHomePath) {
       return undefined;
@@ -2266,6 +2306,11 @@ export default function ChatView({ threadId }: ChatViewProps) {
     const composerImagesSnapshot = [...composerImages];
     const messageIdForSend = newMessageId();
     const messageCreatedAt = new Date().toISOString();
+    const outgoingMessageText = formatOutgoingPrompt({
+      provider: selectedProvider,
+      effort: selectedEffort,
+      text: trimmed || IMAGE_ONLY_BOOTSTRAP_PROMPT,
+    });
     const turnAttachmentsPromise = Promise.all(
       composerImagesSnapshot.map(async (image) => ({
         type: "image" as const,
@@ -2288,7 +2333,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
       {
         id: messageIdForSend,
         role: "user",
-        text: trimmed,
+        text: outgoingMessageText,
         ...(optimisticAttachments.length > 0 ? { attachments: optimisticAttachments } : {}),
         createdAt: messageCreatedAt,
         streaming: false,
@@ -2426,7 +2471,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
         message: {
           messageId: messageIdForSend,
           role: "user",
-          text: trimmed || IMAGE_ONLY_BOOTSTRAP_PROMPT,
+          text: outgoingMessageText,
           attachments: turnAttachments,
         },
         model: selectedModel || undefined,
@@ -2667,6 +2712,11 @@ export default function ChatView({ threadId }: ChatViewProps) {
       const threadIdForSend = activeThread.id;
       const messageIdForSend = newMessageId();
       const messageCreatedAt = new Date().toISOString();
+      const outgoingMessageText = formatOutgoingPrompt({
+        provider: selectedProvider,
+        effort: selectedEffort,
+        text: trimmed,
+      });
 
       sendInFlightRef.current = true;
       beginSendPhase("sending-turn");
@@ -2676,7 +2726,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
         {
           id: messageIdForSend,
           role: "user",
-          text: trimmed,
+          text: outgoingMessageText,
           createdAt: messageCreatedAt,
           streaming: false,
         },
@@ -2704,7 +2754,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
           message: {
             messageId: messageIdForSend,
             role: "user",
-            text: trimmed,
+            text: outgoingMessageText,
             attachments: [],
           },
           provider: selectedProvider,
@@ -2748,6 +2798,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
       persistThreadSettingsForNextTurn,
       resetSendPhase,
       runtimeMode,
+      selectedEffort,
       selectedModel,
       selectedModelOptionsForDispatch,
       providerOptionsForDispatch,
@@ -2777,6 +2828,11 @@ export default function ChatView({ threadId }: ChatViewProps) {
     const nextThreadId = newThreadId();
     const planMarkdown = activeProposedPlan.planMarkdown;
     const implementationPrompt = buildPlanImplementationPrompt(planMarkdown);
+    const outgoingImplementationPrompt = formatOutgoingPrompt({
+      provider: selectedProvider,
+      effort: selectedEffort,
+      text: implementationPrompt,
+    });
     const nextThreadTitle = truncateTitle(buildPlanImplementationThreadTitle(planMarkdown));
     const nextThreadModel: ModelSlug =
       selectedModel ||
@@ -2813,7 +2869,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
           message: {
             messageId: newMessageId(),
             role: "user",
-            text: implementationPrompt,
+            text: outgoingImplementationPrompt,
             attachments: [],
           },
           provider: selectedProvider,
@@ -2871,6 +2927,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
     navigate,
     resetSendPhase,
     runtimeMode,
+    selectedEffort,
     selectedModel,
     selectedModelOptionsForDispatch,
     providerOptionsForDispatch,
@@ -2903,7 +2960,7 @@ export default function ChatView({ threadId }: ChatViewProps) {
     ],
   );
   const onEffortSelect = useCallback(
-    (effort: CodexReasoningEffort) => {
+    (effort: ProviderReasoningEffort) => {
       setComposerDraftEffort(threadId, effort);
       scheduleComposerFocus();
     },
@@ -3335,474 +3392,504 @@ export default function ChatView({ threadId }: ChatViewProps) {
               data-chat-composer-form="true"
             >
               <div
-                className={`group rounded-[20px] border bg-card transition-colors duration-200 focus-within:border-ring/45 ${
-                  isDragOverComposer ? "border-primary/70 bg-accent/30" : "border-border"
-                }`}
+                className={cn(
+                  "group rounded-[22px] transition-colors duration-200",
+                  isClaudeUltrathink ? "ultrathink-frame p-[2px]" : "p-px",
+                )}
                 onDragEnter={onComposerDragEnter}
                 onDragOver={onComposerDragOver}
                 onDragLeave={onComposerDragLeave}
                 onDrop={onComposerDrop}
               >
-                {activePendingApproval ? (
-                  <div className="rounded-t-[19px] border-b border-border/65 bg-muted/20">
-                    <ComposerPendingApprovalPanel
-                      approval={activePendingApproval}
-                      pendingCount={pendingApprovals.length}
-                    />
-                  </div>
-                ) : pendingUserInputs.length > 0 ? (
-                  <div className="rounded-t-[19px] border-b border-border/65 bg-muted/20">
-                    <ComposerPendingUserInputPanel
-                      pendingUserInputs={pendingUserInputs}
-                      respondingRequestIds={respondingRequestIds}
-                      answers={activePendingDraftAnswers}
-                      questionIndex={activePendingQuestionIndex}
-                      onSelectOption={onSelectActivePendingUserInputOption}
-                      onAdvance={onAdvanceActivePendingUserInput}
-                    />
-                  </div>
-                ) : showPlanFollowUpPrompt && activeProposedPlan ? (
-                  <div className="rounded-t-[19px] border-b border-border/65 bg-muted/20">
-                    <ComposerPlanFollowUpBanner
-                      key={activeProposedPlan.id}
-                      planTitle={proposedPlanTitle(activeProposedPlan.planMarkdown) ?? null}
-                    />
-                  </div>
-                ) : null}
-
-                {/* Textarea area */}
                 <div
                   className={cn(
-                    "relative px-3 pb-2 sm:px-4",
-                    hasComposerHeader ? "pt-2.5 sm:pt-3" : "pt-3.5 sm:pt-4",
+                    "rounded-[20px] border bg-card transition-colors duration-200 focus-within:border-ring/45",
+                    isDragOverComposer ? "border-primary/70 bg-accent/30" : "border-border",
+                    isClaudeUltrathink ? "shadow-[0_0_0_1px_rgba(255,255,255,0.04)_inset]" : "",
                   )}
                 >
-                  {composerMenuOpen && !isComposerApprovalState && (
-                    <div className="absolute inset-x-0 bottom-full z-20 mb-2 px-1">
-                      <ComposerCommandMenu
-                        items={composerMenuItems}
-                        resolvedTheme={resolvedTheme}
-                        isLoading={isComposerMenuLoading}
-                        triggerKind={composerTriggerKind}
-                        activeItemId={activeComposerMenuItem?.id ?? null}
-                        onHighlightedItemChange={onComposerMenuItemHighlighted}
-                        onSelect={onSelectComposerItem}
+                  {activePendingApproval ? (
+                    <div className="rounded-t-[19px] border-b border-border/65 bg-muted/20">
+                      <ComposerPendingApprovalPanel
+                        approval={activePendingApproval}
+                        pendingCount={pendingApprovals.length}
                       />
                     </div>
-                  )}
+                  ) : pendingUserInputs.length > 0 ? (
+                    <div className="rounded-t-[19px] border-b border-border/65 bg-muted/20">
+                      <ComposerPendingUserInputPanel
+                        pendingUserInputs={pendingUserInputs}
+                        respondingRequestIds={respondingRequestIds}
+                        answers={activePendingDraftAnswers}
+                        questionIndex={activePendingQuestionIndex}
+                        onSelectOption={onSelectActivePendingUserInputOption}
+                        onAdvance={onAdvanceActivePendingUserInput}
+                      />
+                    </div>
+                  ) : showPlanFollowUpPrompt && activeProposedPlan ? (
+                    <div className="rounded-t-[19px] border-b border-border/65 bg-muted/20">
+                      <ComposerPlanFollowUpBanner
+                        key={activeProposedPlan.id}
+                        planTitle={proposedPlanTitle(activeProposedPlan.planMarkdown) ?? null}
+                      />
+                    </div>
+                  ) : null}
 
-                  {!isComposerApprovalState &&
-                    pendingUserInputs.length === 0 &&
-                    composerImages.length > 0 && (
-                      <div className="mb-3 flex flex-wrap gap-2">
-                        {composerImages.map((image) => (
-                          <div
-                            key={image.id}
-                            className="relative h-16 w-16 overflow-hidden rounded-lg border border-border/80 bg-background"
-                          >
-                            {image.previewUrl ? (
-                              <button
-                                type="button"
-                                className="h-full w-full cursor-zoom-in"
-                                aria-label={`Preview ${image.name}`}
-                                onClick={() => {
-                                  const preview = buildExpandedImagePreview(
-                                    composerImages,
-                                    image.id,
-                                  );
-                                  if (!preview) return;
-                                  setExpandedImage(preview);
-                                }}
-                              >
-                                <img
-                                  src={image.previewUrl}
-                                  alt={image.name}
-                                  className="h-full w-full object-cover"
-                                />
-                              </button>
-                            ) : (
-                              <div className="flex h-full w-full items-center justify-center px-1 text-center text-[10px] text-muted-foreground/70">
-                                {image.name}
-                              </div>
-                            )}
-                            {nonPersistedComposerImageIdSet.has(image.id) && (
-                              <Tooltip>
-                                <TooltipTrigger
-                                  render={
-                                    <span
-                                      role="img"
-                                      aria-label="Draft attachment may not persist"
-                                      className="absolute left-1 top-1 inline-flex items-center justify-center rounded bg-background/85 p-0.5 text-amber-600"
-                                    >
-                                      <CircleAlertIcon className="size-3" />
-                                    </span>
-                                  }
-                                />
-                                <TooltipPopup
-                                  side="top"
-                                  className="max-w-64 whitespace-normal leading-tight"
-                                >
-                                  Draft attachment could not be saved locally and may be lost on
-                                  navigation.
-                                </TooltipPopup>
-                              </Tooltip>
-                            )}
-                            <Button
-                              variant="ghost"
-                              size="icon-xs"
-                              className="absolute right-1 top-1 bg-background/80 hover:bg-background/90"
-                              onClick={() => removeComposerImage(image.id)}
-                              aria-label={`Remove ${image.name}`}
-                            >
-                              <XIcon />
-                            </Button>
-                          </div>
-                        ))}
+                  {/* Textarea area */}
+                  <div
+                    className={cn(
+                      "relative px-3 pb-2 sm:px-4",
+                      hasComposerHeader ? "pt-2.5 sm:pt-3" : "pt-3.5 sm:pt-4",
+                    )}
+                  >
+                    {isClaudeUltrathink ? (
+                      <div className="mb-2 flex items-center gap-2">
+                        <span className="ultrathink-pill inline-flex items-center rounded-md border border-transparent px-2.5 py-0.5 font-medium text-[12px] sm:text-[13px]">
+                          <span className="ultrathink-word">Ultrathink</span>
+                        </span>
+                      </div>
+                    ) : null}
+                    {composerMenuOpen && !isComposerApprovalState && (
+                      <div className="absolute inset-x-0 bottom-full z-20 mb-2 px-1">
+                        <ComposerCommandMenu
+                          items={composerMenuItems}
+                          resolvedTheme={resolvedTheme}
+                          isLoading={isComposerMenuLoading}
+                          triggerKind={composerTriggerKind}
+                          activeItemId={activeComposerMenuItem?.id ?? null}
+                          onHighlightedItemChange={onComposerMenuItemHighlighted}
+                          onSelect={onSelectComposerItem}
+                        />
                       </div>
                     )}
-                  <ComposerPromptEditor
-                    ref={composerEditorRef}
-                    value={
-                      isComposerApprovalState
-                        ? ""
-                        : activePendingProgress
-                          ? activePendingProgress.customAnswer
-                          : prompt
-                    }
-                    cursor={composerCursor}
-                    onChange={onPromptChange}
-                    onCommandKeyDown={onComposerCommandKey}
-                    onPaste={onComposerPaste}
-                    placeholder={
-                      isComposerApprovalState
-                        ? (activePendingApproval?.detail ??
-                          "Resolve this approval request to continue")
-                        : activePendingProgress
-                          ? "Type your own answer, or leave this blank to use the selected option"
-                          : showPlanFollowUpPrompt && activeProposedPlan
-                            ? "Add feedback to refine the plan, or leave this blank to implement it"
-                            : phase === "disconnected"
-                              ? "Ask for follow-up changes or attach images"
-                              : "Ask anything, @tag files/folders, or use / to show available commands"
-                    }
-                    disabled={isConnecting || isComposerApprovalState}
-                  />
-                </div>
 
-                {/* Bottom toolbar */}
-                {activePendingApproval ? (
-                  <div className="flex items-center justify-end gap-2 px-2.5 pb-2.5 sm:px-3 sm:pb-3">
-                    <ComposerPendingApprovalActions
-                      requestId={activePendingApproval.requestId}
-                      isResponding={respondingRequestIds.includes(activePendingApproval.requestId)}
-                      onRespondToApproval={onRespondToApproval}
+                    {!isComposerApprovalState &&
+                      pendingUserInputs.length === 0 &&
+                      composerImages.length > 0 && (
+                        <div className="mb-3 flex flex-wrap gap-2">
+                          {composerImages.map((image) => (
+                            <div
+                              key={image.id}
+                              className="relative h-16 w-16 overflow-hidden rounded-lg border border-border/80 bg-background"
+                            >
+                              {image.previewUrl ? (
+                                <button
+                                  type="button"
+                                  className="h-full w-full cursor-zoom-in"
+                                  aria-label={`Preview ${image.name}`}
+                                  onClick={() => {
+                                    const preview = buildExpandedImagePreview(
+                                      composerImages,
+                                      image.id,
+                                    );
+                                    if (!preview) return;
+                                    setExpandedImage(preview);
+                                  }}
+                                >
+                                  <img
+                                    src={image.previewUrl}
+                                    alt={image.name}
+                                    className="h-full w-full object-cover"
+                                  />
+                                </button>
+                              ) : (
+                                <div className="flex h-full w-full items-center justify-center px-1 text-center text-[10px] text-muted-foreground/70">
+                                  {image.name}
+                                </div>
+                              )}
+                              {nonPersistedComposerImageIdSet.has(image.id) && (
+                                <Tooltip>
+                                  <TooltipTrigger
+                                    render={
+                                      <span
+                                        role="img"
+                                        aria-label="Draft attachment may not persist"
+                                        className="absolute left-1 top-1 inline-flex items-center justify-center rounded bg-background/85 p-0.5 text-amber-600"
+                                      >
+                                        <CircleAlertIcon className="size-3" />
+                                      </span>
+                                    }
+                                  />
+                                  <TooltipPopup
+                                    side="top"
+                                    className="max-w-64 whitespace-normal leading-tight"
+                                  >
+                                    Draft attachment could not be saved locally and may be lost on
+                                    navigation.
+                                  </TooltipPopup>
+                                </Tooltip>
+                              )}
+                              <Button
+                                variant="ghost"
+                                size="icon-xs"
+                                className="absolute right-1 top-1 bg-background/80 hover:bg-background/90"
+                                onClick={() => removeComposerImage(image.id)}
+                                aria-label={`Remove ${image.name}`}
+                              >
+                                <XIcon />
+                              </Button>
+                            </div>
+                          ))}
+                        </div>
+                      )}
+                    <ComposerPromptEditor
+                      ref={composerEditorRef}
+                      value={
+                        isComposerApprovalState
+                          ? ""
+                          : activePendingProgress
+                            ? activePendingProgress.customAnswer
+                            : prompt
+                      }
+                      cursor={composerCursor}
+                      onChange={onPromptChange}
+                      onCommandKeyDown={onComposerCommandKey}
+                      onPaste={onComposerPaste}
+                      placeholder={
+                        isComposerApprovalState
+                          ? (activePendingApproval?.detail ??
+                            "Resolve this approval request to continue")
+                          : activePendingProgress
+                            ? "Type your own answer, or leave this blank to use the selected option"
+                            : showPlanFollowUpPrompt && activeProposedPlan
+                              ? "Add feedback to refine the plan, or leave this blank to implement it"
+                              : phase === "disconnected"
+                                ? "Ask for follow-up changes or attach images"
+                                : "Ask anything, @tag files/folders, or use / to show available commands"
+                      }
+                      disabled={isConnecting || isComposerApprovalState}
                     />
                   </div>
-                ) : (
-                  <div
-                    data-chat-composer-footer="true"
-                    className={cn(
-                      "flex items-center justify-between px-2.5 pb-2.5 sm:px-3 sm:pb-3",
-                      isComposerFooterCompact
-                        ? "gap-1.5"
-                        : "flex-wrap gap-2 sm:flex-nowrap sm:gap-0",
-                    )}
-                  >
+
+                  {/* Bottom toolbar */}
+                  {activePendingApproval ? (
+                    <div className="flex items-center justify-end gap-2 px-2.5 pb-2.5 sm:px-3 sm:pb-3">
+                      <ComposerPendingApprovalActions
+                        requestId={activePendingApproval.requestId}
+                        isResponding={respondingRequestIds.includes(
+                          activePendingApproval.requestId,
+                        )}
+                        onRespondToApproval={onRespondToApproval}
+                      />
+                    </div>
+                  ) : (
                     <div
+                      data-chat-composer-footer="true"
                       className={cn(
-                        "flex min-w-0 flex-1 items-center",
+                        "flex items-center justify-between px-2.5 pb-2.5 sm:px-3 sm:pb-3",
                         isComposerFooterCompact
-                          ? "gap-1 overflow-hidden"
-                          : "gap-1 overflow-x-auto [scrollbar-width:none] [&::-webkit-scrollbar]:hidden sm:min-w-max sm:overflow-visible",
+                          ? "gap-1.5"
+                          : "flex-wrap gap-2 sm:flex-nowrap sm:gap-0",
                       )}
                     >
-                      {/* Provider/model picker */}
-                      <ProviderModelPicker
-                        compact={isComposerFooterCompact}
-                        provider={selectedProvider}
-                        model={selectedModelForPickerWithCustomFallback}
-                        lockedProvider={lockedProvider}
-                        modelOptionsByProvider={modelOptionsByProvider}
-                        onProviderModelChange={onProviderModelSelect}
-                      />
-
-                      {isComposerFooterCompact ? (
-                        <CompactComposerControlsMenu
-                          activePlan={Boolean(activePlan || activeProposedPlan || planSidebarOpen)}
-                          interactionMode={interactionMode}
-                          planSidebarOpen={planSidebarOpen}
-                          runtimeMode={runtimeMode}
-                          selectedEffort={selectedEffort}
-                          selectedProvider={selectedProvider}
-                          selectedCodexFastModeEnabled={selectedCodexFastModeEnabled}
-                          reasoningOptions={reasoningOptions}
-                          onEffortSelect={onEffortSelect}
-                          onCodexFastModeChange={onCodexFastModeChange}
-                          onToggleInteractionMode={toggleInteractionMode}
-                          onTogglePlanSidebar={togglePlanSidebar}
-                          onToggleRuntimeMode={toggleRuntimeMode}
+                      <div
+                        className={cn(
+                          "flex min-w-0 flex-1 items-center",
+                          isComposerFooterCompact
+                            ? "gap-1 overflow-hidden"
+                            : "gap-1 overflow-x-auto [scrollbar-width:none] [&::-webkit-scrollbar]:hidden sm:min-w-max sm:overflow-visible",
+                        )}
+                      >
+                        {/* Provider/model picker */}
+                        <ProviderModelPicker
+                          compact={isComposerFooterCompact}
+                          provider={selectedProvider}
+                          model={selectedModelForPickerWithCustomFallback}
+                          lockedProvider={lockedProvider}
+                          modelOptionsByProvider={modelOptionsByProvider}
+                          ultrathinkActive={isClaudeUltrathink}
+                          onProviderModelChange={onProviderModelSelect}
                         />
-                      ) : (
-                        <>
-                          {selectedProvider === "codex" && selectedEffort != null ? (
-                            <>
-                              <Separator
-                                orientation="vertical"
-                                className="mx-0.5 hidden h-4 sm:block"
-                              />
-                              <CodexTraitsPicker
-                                effort={selectedEffort}
-                                fastModeEnabled={selectedCodexFastModeEnabled}
-                                options={reasoningOptions}
-                                onEffortChange={onEffortSelect}
-                                onFastModeChange={onCodexFastModeChange}
-                              />
-                            </>
-                          ) : null}
-
-                          <Separator
-                            orientation="vertical"
-                            className="mx-0.5 hidden h-4 sm:block"
-                          />
 
-                          <Button
-                            variant="ghost"
-                            className="shrink-0 whitespace-nowrap px-2 text-muted-foreground/70 hover:text-foreground/80 sm:px-3"
-                            size="sm"
-                            type="button"
-                            onClick={toggleInteractionMode}
-                            title={
-                              interactionMode === "plan"
-                                ? "Plan mode — click to return to normal chat mode"
-                                : "Default mode — click to enter plan mode"
-                            }
-                          >
-                            <BotIcon />
-                            <span className="sr-only sm:not-sr-only">
-                              {interactionMode === "plan" ? "Plan" : "Chat"}
-                            </span>
-                          </Button>
-
-                          <Separator
-                            orientation="vertical"
-                            className="mx-0.5 hidden h-4 sm:block"
+                        {isComposerFooterCompact ? (
+                          <CompactComposerControlsMenu
+                            activePlan={Boolean(
+                              activePlan || activeProposedPlan || planSidebarOpen,
+                            )}
+                            interactionMode={interactionMode}
+                            planSidebarOpen={planSidebarOpen}
+                            runtimeMode={runtimeMode}
+                            selectedEffort={selectedEffort}
+                            selectedProvider={selectedProvider}
+                            selectedCodexFastModeEnabled={selectedCodexFastModeEnabled}
+                            reasoningOptions={reasoningOptions}
+                            onEffortSelect={onEffortSelect}
+                            onCodexFastModeChange={onCodexFastModeChange}
+                            onToggleInteractionMode={toggleInteractionMode}
+                            onTogglePlanSidebar={togglePlanSidebar}
+                            onToggleRuntimeMode={toggleRuntimeMode}
                           />
+                        ) : (
+                          <>
+                            {selectedEffort != null ? (
+                              <>
+                                <Separator
+                                  orientation="vertical"
+                                  className="mx-0.5 hidden h-4 sm:block"
+                                />
+                                <ProviderTraitsPicker
+                                  provider={selectedProvider}
+                                  effort={selectedEffort}
+                                  options={reasoningOptions}
+                                  onEffortChange={onEffortSelect}
+                                  {...(selectedProvider === "codex"
+                                    ? {
+                                        fastModeEnabled: selectedCodexFastModeEnabled,
+                                        onFastModeChange: onCodexFastModeChange,
+                                      }
+                                    : {})}
+                                />
+                              </>
+                            ) : null}
 
-                          <Button
-                            variant="ghost"
-                            className="shrink-0 whitespace-nowrap px-2 text-muted-foreground/70 hover:text-foreground/80 sm:px-3"
-                            size="sm"
-                            type="button"
-                            onClick={() =>
-                              void handleRuntimeModeChange(
-                                runtimeMode === "full-access" ? "approval-required" : "full-access",
-                              )
-                            }
-                            title={
-                              runtimeMode === "full-access"
-                                ? "Full access — click to require approvals"
-                                : "Approval required — click for full access"
-                            }
-                          >
-                            {runtimeMode === "full-access" ? <LockOpenIcon /> : <LockIcon />}
-                            <span className="sr-only sm:not-sr-only">
-                              {runtimeMode === "full-access" ? "Full access" : "Supervised"}
-                            </span>
-                          </Button>
-
-                          {activePlan || activeProposedPlan || planSidebarOpen ? (
-                            <>
-                              <Separator
-                                orientation="vertical"
-                                className="mx-0.5 hidden h-4 sm:block"
-                              />
-                              <Button
-                                variant="ghost"
-                                className={cn(
-                                  "shrink-0 whitespace-nowrap px-2 sm:px-3",
-                                  planSidebarOpen
-                                    ? "text-blue-400 hover:text-blue-300"
-                                    : "text-muted-foreground/70 hover:text-foreground/80",
-                                )}
-                                size="sm"
-                                type="button"
-                                onClick={togglePlanSidebar}
-                                title={planSidebarOpen ? "Hide plan sidebar" : "Show plan sidebar"}
-                              >
-                                <ListTodoIcon />
-                                <span className="sr-only sm:not-sr-only">Plan</span>
-                              </Button>
-                            </>
-                          ) : null}
-                        </>
-                      )}
-                    </div>
+                            <Separator
+                              orientation="vertical"
+                              className="mx-0.5 hidden h-4 sm:block"
+                            />
 
-                    {/* Right side: send / stop button */}
-                    <div
-                      data-chat-composer-actions="right"
-                      className="flex shrink-0 items-center gap-2"
-                    >
-                      {isPreparingWorktree ? (
-                        <span className="text-muted-foreground/70 text-xs">
-                          Preparing worktree...
-                        </span>
-                      ) : null}
-                      {activePendingProgress ? (
-                        <div className="flex items-center gap-2">
-                          {activePendingProgress.questionIndex > 0 ? (
                             <Button
+                              variant="ghost"
+                              className="shrink-0 whitespace-nowrap px-2 text-muted-foreground/70 hover:text-foreground/80 sm:px-3"
                               size="sm"
-                              variant="outline"
-                              className="rounded-full"
-                              onClick={onPreviousActivePendingUserInputQuestion}
-                              disabled={activePendingIsResponding}
+                              type="button"
+                              onClick={toggleInteractionMode}
+                              title={
+                                interactionMode === "plan"
+                                  ? "Plan mode — click to return to normal chat mode"
+                                  : "Default mode — click to enter plan mode"
+                              }
                             >
-                              Previous
+                              <BotIcon />
+                              <span className="sr-only sm:not-sr-only">
+                                {interactionMode === "plan" ? "Plan" : "Chat"}
+                              </span>
                             </Button>
-                          ) : null}
-                          <Button
-                            type="submit"
-                            size="sm"
-                            className="rounded-full px-4"
-                            disabled={
-                              activePendingIsResponding ||
-                              (activePendingProgress.isLastQuestion
-                                ? !activePendingResolvedAnswers
-                                : !activePendingProgress.canAdvance)
-                            }
-                          >
-                            {activePendingIsResponding
-                              ? "Submitting..."
-                              : activePendingProgress.isLastQuestion
-                                ? "Submit answers"
-                                : "Next question"}
-                          </Button>
-                        </div>
-                      ) : phase === "running" ? (
-                        <button
-                          type="button"
-                          className="flex size-8 cursor-pointer items-center justify-center rounded-full bg-rose-500/90 text-white transition-all duration-150 hover:bg-rose-500 hover:scale-105 sm:h-8 sm:w-8"
-                          onClick={() => void onInterrupt()}
-                          aria-label="Stop generation"
-                        >
-                          <svg
-                            width="12"
-                            height="12"
-                            viewBox="0 0 12 12"
-                            fill="currentColor"
-                            aria-hidden="true"
-                          >
-                            <rect x="2" y="2" width="8" height="8" rx="1.5" />
-                          </svg>
-                        </button>
-                      ) : pendingUserInputs.length === 0 ? (
-                        showPlanFollowUpPrompt ? (
-                          prompt.trim().length > 0 ? (
+
+                            <Separator
+                              orientation="vertical"
+                              className="mx-0.5 hidden h-4 sm:block"
+                            />
+
+                            <Button
+                              variant="ghost"
+                              className="shrink-0 whitespace-nowrap px-2 text-muted-foreground/70 hover:text-foreground/80 sm:px-3"
+                              size="sm"
+                              type="button"
+                              onClick={() =>
+                                void handleRuntimeModeChange(
+                                  runtimeMode === "full-access"
+                                    ? "approval-required"
+                                    : "full-access",
+                                )
+                              }
+                              title={
+                                runtimeMode === "full-access"
+                                  ? "Full access — click to require approvals"
+                                  : "Approval required — click for full access"
+                              }
+                            >
+                              {runtimeMode === "full-access" ? <LockOpenIcon /> : <LockIcon />}
+                              <span className="sr-only sm:not-sr-only">
+                                {runtimeMode === "full-access" ? "Full access" : "Supervised"}
+                              </span>
+                            </Button>
+
+                            {activePlan || activeProposedPlan || planSidebarOpen ? (
+                              <>
+                                <Separator
+                                  orientation="vertical"
+                                  className="mx-0.5 hidden h-4 sm:block"
+                                />
+                                <Button
+                                  variant="ghost"
+                                  className={cn(
+                                    "shrink-0 whitespace-nowrap px-2 sm:px-3",
+                                    planSidebarOpen
+                                      ? "text-blue-400 hover:text-blue-300"
+                                      : "text-muted-foreground/70 hover:text-foreground/80",
+                                  )}
+                                  size="sm"
+                                  type="button"
+                                  onClick={togglePlanSidebar}
+                                  title={
+                                    planSidebarOpen ? "Hide plan sidebar" : "Show plan sidebar"
+                                  }
+                                >
+                                  <ListTodoIcon />
+                                  <span className="sr-only sm:not-sr-only">Plan</span>
+                                </Button>
+                              </>
+                            ) : null}
+                          </>
+                        )}
+                      </div>
+
+                      {/* Right side: send / stop button */}
+                      <div
+                        data-chat-composer-actions="right"
+                        className="flex shrink-0 items-center gap-2"
+                      >
+                        {isPreparingWorktree ? (
+                          <span className="text-muted-foreground/70 text-xs">
+                            Preparing worktree...
+                          </span>
+                        ) : null}
+                        {activePendingProgress ? (
+                          <div className="flex items-center gap-2">
+                            {activePendingProgress.questionIndex > 0 ? (
+                              <Button
+                                size="sm"
+                                variant="outline"
+                                className="rounded-full"
+                                onClick={onPreviousActivePendingUserInputQuestion}
+                                disabled={activePendingIsResponding}
+                              >
+                                Previous
+                              </Button>
+                            ) : null}
                             <Button
                               type="submit"
                               size="sm"
-                              className="h-9 rounded-full px-4 sm:h-8"
-                              disabled={isSendBusy || isConnecting}
+                              className="rounded-full px-4"
+                              disabled={
+                                activePendingIsResponding ||
+                                (activePendingProgress.isLastQuestion
+                                  ? !activePendingResolvedAnswers
+                                  : !activePendingProgress.canAdvance)
+                              }
                             >
-                              {isConnecting || isSendBusy ? "Sending..." : "Refine"}
+                              {activePendingIsResponding
+                                ? "Submitting..."
+                                : activePendingProgress.isLastQuestion
+                                  ? "Submit answers"
+                                  : "Next question"}
                             </Button>
-                          ) : (
-                            <div className="flex items-center">
+                          </div>
+                        ) : phase === "running" ? (
+                          <button
+                            type="button"
+                            className="flex size-8 cursor-pointer items-center justify-center rounded-full bg-rose-500/90 text-white transition-all duration-150 hover:bg-rose-500 hover:scale-105 sm:h-8 sm:w-8"
+                            onClick={() => void onInterrupt()}
+                            aria-label="Stop generation"
+                          >
+                            <svg
+                              width="12"
+                              height="12"
+                              viewBox="0 0 12 12"
+                              fill="currentColor"
+                              aria-hidden="true"
+                            >
+                              <rect x="2" y="2" width="8" height="8" rx="1.5" />
+                            </svg>
+                          </button>
+                        ) : pendingUserInputs.length === 0 ? (
+                          showPlanFollowUpPrompt ? (
+                            prompt.trim().length > 0 ? (
                               <Button
                                 type="submit"
                                 size="sm"
-                                className="h-9 rounded-l-full rounded-r-none px-4 sm:h-8"
+                                className="h-9 rounded-full px-4 sm:h-8"
                                 disabled={isSendBusy || isConnecting}
                               >
-                                {isConnecting || isSendBusy ? "Sending..." : "Implement"}
+                                {isConnecting || isSendBusy ? "Sending..." : "Refine"}
                               </Button>
-                              <Menu>
-                                <MenuTrigger
-                                  render={
-                                    <Button
-                                      size="sm"
-                                      variant="default"
-                                      className="h-9 rounded-l-none rounded-r-full border-l-white/12 px-2 sm:h-8"
-                                      aria-label="Implementation actions"
-                                      disabled={isSendBusy || isConnecting}
-                                    />
-                                  }
+                            ) : (
+                              <div className="flex items-center">
+                                <Button
+                                  type="submit"
+                                  size="sm"
+                                  className="h-9 rounded-l-full rounded-r-none px-4 sm:h-8"
+                                  disabled={isSendBusy || isConnecting}
                                 >
-                                  <ChevronDownIcon className="size-3.5" />
-                                </MenuTrigger>
-                                <MenuPopup align="end" side="top">
-                                  <MenuItem
-                                    disabled={isSendBusy || isConnecting}
-                                    onClick={() => void onImplementPlanInNewThread()}
+                                  {isConnecting || isSendBusy ? "Sending..." : "Implement"}
+                                </Button>
+                                <Menu>
+                                  <MenuTrigger
+                                    render={
+                                      <Button
+                                        size="sm"
+                                        variant="default"
+                                        className="h-9 rounded-l-none rounded-r-full border-l-white/12 px-2 sm:h-8"
+                                        aria-label="Implementation actions"
+                                        disabled={isSendBusy || isConnecting}
+                                      />
+                                    }
                                   >
-                                    Implement in new thread
-                                  </MenuItem>
-                                </MenuPopup>
-                              </Menu>
-                            </div>
+                                    <ChevronDownIcon className="size-3.5" />
+                                  </MenuTrigger>
+                                  <MenuPopup align="end" side="top">
+                                    <MenuItem
+                                      disabled={isSendBusy || isConnecting}
+                                      onClick={() => void onImplementPlanInNewThread()}
+                                    >
+                                      Implement in new thread
+                                    </MenuItem>
+                                  </MenuPopup>
+                                </Menu>
+                              </div>
+                            )
+                          ) : (
+                            <button
+                              type="submit"
+                              className="flex h-9 w-9 items-center justify-center rounded-full bg-primary/90 text-primary-foreground transition-all duration-150 hover:bg-primary hover:scale-105 disabled:opacity-30 disabled:hover:scale-100 sm:h-8 sm:w-8"
+                              disabled={
+                                isSendBusy ||
+                                isConnecting ||
+                                (!prompt.trim() && composerImages.length === 0)
+                              }
+                              aria-label={
+                                isConnecting
+                                  ? "Connecting"
+                                  : isPreparingWorktree
+                                    ? "Preparing worktree"
+                                    : isSendBusy
+                                      ? "Sending"
+                                      : "Send message"
+                              }
+                            >
+                              {isConnecting || isSendBusy ? (
+                                <svg
+                                  width="14"
+                                  height="14"
+                                  viewBox="0 0 14 14"
+                                  fill="none"
+                                  className="animate-spin"
+                                  aria-hidden="true"
+                                >
+                                  <circle
+                                    cx="7"
+                                    cy="7"
+                                    r="5.5"
+                                    stroke="currentColor"
+                                    strokeWidth="1.5"
+                                    strokeLinecap="round"
+                                    strokeDasharray="20 12"
+                                  />
+                                </svg>
+                              ) : (
+                                <svg
+                                  width="14"
+                                  height="14"
+                                  viewBox="0 0 14 14"
+                                  fill="none"
+                                  aria-hidden="true"
+                                >
+                                  <path
+                                    d="M7 11.5V2.5M7 2.5L3 6.5M7 2.5L11 6.5"
+                                    stroke="currentColor"
+                                    strokeWidth="1.8"
+                                    strokeLinecap="round"
+                                    strokeLinejoin="round"
+                                  />
+                                </svg>
+                              )}
+                            </button>
                           )
-                        ) : (
-                          <button
-                            type="submit"
-                            className="flex h-9 w-9 items-center justify-center rounded-full bg-primary/90 text-primary-foreground transition-all duration-150 hover:bg-primary hover:scale-105 disabled:opacity-30 disabled:hover:scale-100 sm:h-8 sm:w-8"
-                            disabled={
-                              isSendBusy ||
-                              isConnecting ||
-                              (!prompt.trim() && composerImages.length === 0)
-                            }
-                            aria-label={
-                              isConnecting
-                                ? "Connecting"
-                                : isPreparingWorktree
-                                  ? "Preparing worktree"
-                                  : isSendBusy
-                                    ? "Sending"
-                                    : "Send message"
-                            }
-                          >
-                            {isConnecting || isSendBusy ? (
-                              <svg
-                                width="14"
-                                height="14"
-                                viewBox="0 0 14 14"
-                                fill="none"
-                                className="animate-spin"
-                                aria-hidden="true"
-                              >
-                                <circle
-                                  cx="7"
-                                  cy="7"
-                                  r="5.5"
-                                  stroke="currentColor"
-                                  strokeWidth="1.5"
-                                  strokeLinecap="round"
-                                  strokeDasharray="20 12"
-                                />
-                              </svg>
-                            ) : (
-                              <svg
-                                width="14"
-                                height="14"
-                                viewBox="0 0 14 14"
-                                fill="none"
-                                aria-hidden="true"
-                              >
-                                <path
-                                  d="M7 11.5V2.5M7 2.5L3 6.5M7 2.5L11 6.5"
-                                  stroke="currentColor"
-                                  strokeWidth="1.8"
-                                  strokeLinecap="round"
-                                  strokeLinejoin="round"
-                                />
-                              </svg>
-                            )}
-                          </button>
-                        )
-                      ) : null}
+                        ) : null}
+                      </div>
                     </div>
-                  </div>
-                )}
+                  )}
+                </div>
               </div>
             </form>
           </div>
diff --git a/apps/web/src/components/Icons.tsx b/apps/web/src/components/Icons.tsx
index 9a3ddbaa0..7d210fa17 100644
--- a/apps/web/src/components/Icons.tsx
+++ b/apps/web/src/components/Icons.tsx
@@ -146,7 +146,7 @@ export const OpenAI: Icon = (props) => (
 export const ClaudeAI: Icon = (props) => (
   <svg {...props} preserveAspectRatio="xMidYMid" viewBox="0 0 256 257">
     <path
-      fill="#D97757"
+      fill="currentColor"
       d="m50.228 170.321 50.357-28.257.843-2.463-.843-1.361h-2.462l-8.426-.518-28.775-.778-24.952-1.037-24.175-1.296-6.092-1.297L0 125.796l.583-3.759 5.12-3.434 7.324.648 16.202 1.101 24.304 1.685 17.629 1.037 26.118 2.722h4.148l.583-1.685-1.426-1.037-1.101-1.037-25.147-17.045-27.22-18.017-14.258-10.37-7.713-5.25-3.888-4.925-1.685-10.758 7-7.713 9.397.649 2.398.648 9.527 7.323 20.35 15.75L94.817 91.9l3.889 3.24 1.555-1.102.195-.777-1.75-2.917-14.453-26.118-15.425-26.572-6.87-11.018-1.814-6.61c-.648-2.723-1.102-4.991-1.102-7.778l7.972-10.823L71.42 0 82.05 1.426l4.472 3.888 6.61 15.101 10.694 23.786 16.591 32.34 4.861 9.592 2.592 8.879.973 2.722h1.685v-1.556l1.36-18.211 2.528-22.36 2.463-28.776.843-8.1 4.018-9.722 7.971-5.25 6.222 2.981 5.12 7.324-.713 4.73-3.046 19.768-5.962 30.98-3.889 20.739h2.268l2.593-2.593 10.499-13.934 17.628-22.036 7.778-8.749 9.073-9.657 5.833-4.601h11.018l8.1 12.055-3.628 12.443-11.342 14.388-9.398 12.184-13.48 18.147-8.426 14.518.778 1.166 2.01-.194 30.46-6.481 16.462-2.982 19.637-3.37 8.88 4.148.971 4.213-3.5 8.62-20.998 5.184-24.628 4.926-36.682 8.685-.454.324.519.648 16.526 1.555 7.065.389h17.304l32.21 2.398 8.426 5.574 5.055 6.805-.843 5.184-12.962 6.611-17.498-4.148-40.83-9.721-14-3.5h-1.944v1.167l11.666 11.406 21.387 19.314 26.767 24.887 1.36 6.157-3.434 4.86-3.63-.518-23.526-17.693-9.073-7.972-20.545-17.304h-1.36v1.814l4.73 6.935 25.017 37.59 1.296 11.536-1.814 3.76-6.481 2.268-7.13-1.297-14.647-20.544-15.1-23.138-12.185-20.739-1.49.843-7.194 77.448-3.37 3.953-7.778 2.981-6.48-4.925-3.436-7.972 3.435-15.749 4.148-20.544 3.37-16.333 3.046-20.285 1.815-6.74-.13-.454-1.49.194-15.295 20.999-23.267 31.433-18.406 19.702-4.407 1.75-7.648-3.954.713-7.064 4.277-6.286 25.47-32.405 15.36-20.092 9.917-11.6-.065-1.686h-.583L44.07 198.125l-12.055 1.555-5.185-4.86.648-7.972 2.463-2.593 20.35-13.999-.064.065Z"
     />
   </svg>
diff --git a/apps/web/src/components/chat/CodexTraitsPicker.tsx b/apps/web/src/components/chat/CodexTraitsPicker.tsx
index 6c72f497b..529f2769e 100644
--- a/apps/web/src/components/chat/CodexTraitsPicker.tsx
+++ b/apps/web/src/components/chat/CodexTraitsPicker.tsx
@@ -1,4 +1,4 @@
-import { type CodexReasoningEffort } from "@t3tools/contracts";
+import { type ProviderKind, type ProviderReasoningEffort } from "@t3tools/contracts";
 import { getDefaultReasoningEffort } from "@t3tools/shared/model";
 import { memo, useState } from "react";
 import { ChevronDownIcon } from "lucide-react";
@@ -13,24 +13,40 @@ import {
   MenuTrigger,
 } from "../ui/menu";
 
-export const CodexTraitsPicker = memo(function CodexTraitsPicker(props: {
-  effort: CodexReasoningEffort;
-  fastModeEnabled: boolean;
-  options: ReadonlyArray<CodexReasoningEffort>;
-  onEffortChange: (effort: CodexReasoningEffort) => void;
-  onFastModeChange: (enabled: boolean) => void;
-}) {
-  const [isMenuOpen, setIsMenuOpen] = useState(false);
-  const defaultReasoningEffort = getDefaultReasoningEffort("codex");
-  const reasoningLabelByOption: Record<CodexReasoningEffort, string> = {
+function effortLabel(provider: ProviderKind, effort: ProviderReasoningEffort): string {
+  if (provider === "codex") {
+    const codexLabels: Record<string, string> = {
+      low: "Low",
+      medium: "Medium",
+      high: "High",
+      xhigh: "Extra High",
+    };
+    return codexLabels[effort] ?? effort;
+  }
+
+  const claudeLabels: Record<string, string> = {
     low: "Low",
     medium: "Medium",
     high: "High",
-    xhigh: "Extra High",
+    max: "Max",
+    ultrathink: "Ultrathink",
   };
+  return claudeLabels[effort] ?? effort;
+}
+
+export const ProviderTraitsPicker = memo(function ProviderTraitsPicker(props: {
+  provider: ProviderKind;
+  effort: ProviderReasoningEffort;
+  fastModeEnabled?: boolean;
+  options: ReadonlyArray<ProviderReasoningEffort>;
+  onEffortChange: (effort: ProviderReasoningEffort) => void;
+  onFastModeChange?: (enabled: boolean) => void;
+}) {
+  const [isMenuOpen, setIsMenuOpen] = useState(false);
+  const defaultReasoningEffort = getDefaultReasoningEffort(props.provider);
   const triggerLabel = [
-    reasoningLabelByOption[props.effort],
-    ...(props.fastModeEnabled ? ["Fast"] : []),
+    effortLabel(props.provider, props.effort),
+    ...(props.provider === "codex" && props.fastModeEnabled ? ["Fast"] : []),
   ]
     .filter(Boolean)
     .join(" · ");
@@ -56,7 +72,9 @@ export const CodexTraitsPicker = memo(function CodexTraitsPicker(props: {
       </MenuTrigger>
       <MenuPopup align="start">
         <MenuGroup>
-          <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">Reasoning</div>
+          <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">
+            {props.provider === "codex" ? "Reasoning" : "Effort"}
+          </div>
           <MenuRadioGroup
             value={props.effort}
             onValueChange={(value) => {
@@ -68,25 +86,29 @@ export const CodexTraitsPicker = memo(function CodexTraitsPicker(props: {
           >
             {props.options.map((effort) => (
               <MenuRadioItem key={effort} value={effort}>
-                {reasoningLabelByOption[effort]}
+                {effortLabel(props.provider, effort)}
                 {effort === defaultReasoningEffort ? " (default)" : ""}
               </MenuRadioItem>
             ))}
           </MenuRadioGroup>
         </MenuGroup>
-        <MenuDivider />
-        <MenuGroup>
-          <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">Fast Mode</div>
-          <MenuRadioGroup
-            value={props.fastModeEnabled ? "on" : "off"}
-            onValueChange={(value) => {
-              props.onFastModeChange(value === "on");
-            }}
-          >
-            <MenuRadioItem value="off">off</MenuRadioItem>
-            <MenuRadioItem value="on">on</MenuRadioItem>
-          </MenuRadioGroup>
-        </MenuGroup>
+        {props.provider === "codex" && props.onFastModeChange ? (
+          <>
+            <MenuDivider />
+            <MenuGroup>
+              <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">Fast Mode</div>
+              <MenuRadioGroup
+                value={props.fastModeEnabled ? "on" : "off"}
+                onValueChange={(value) => {
+                  props.onFastModeChange?.(value === "on");
+                }}
+              >
+                <MenuRadioItem value="off">off</MenuRadioItem>
+                <MenuRadioItem value="on">on</MenuRadioItem>
+              </MenuRadioGroup>
+            </MenuGroup>
+          </>
+        ) : null}
       </MenuPopup>
     </Menu>
   );
diff --git a/apps/web/src/components/chat/CompactComposerControlsMenu.tsx b/apps/web/src/components/chat/CompactComposerControlsMenu.tsx
index 0af50ff01..6bca85efe 100644
--- a/apps/web/src/components/chat/CompactComposerControlsMenu.tsx
+++ b/apps/web/src/components/chat/CompactComposerControlsMenu.tsx
@@ -1,8 +1,8 @@
 import {
-  type CodexReasoningEffort,
   type ProviderKind,
   RuntimeMode,
   ProviderInteractionMode,
+  type ProviderReasoningEffort,
 } from "@t3tools/contracts";
 import { getDefaultReasoningEffort } from "@t3tools/shared/model";
 import { memo } from "react";
@@ -24,22 +24,24 @@ export const CompactComposerControlsMenu = memo(function CompactComposerControls
   interactionMode: ProviderInteractionMode;
   planSidebarOpen: boolean;
   runtimeMode: RuntimeMode;
-  selectedEffort: CodexReasoningEffort | null;
+  selectedEffort: ProviderReasoningEffort | null;
   selectedProvider: ProviderKind;
   selectedCodexFastModeEnabled: boolean;
-  reasoningOptions: ReadonlyArray<CodexReasoningEffort>;
-  onEffortSelect: (effort: CodexReasoningEffort) => void;
+  reasoningOptions: ReadonlyArray<ProviderReasoningEffort>;
+  onEffortSelect: (effort: ProviderReasoningEffort) => void;
   onCodexFastModeChange: (enabled: boolean) => void;
   onToggleInteractionMode: () => void;
   onTogglePlanSidebar: () => void;
   onToggleRuntimeMode: () => void;
 }) {
-  const defaultReasoningEffort = getDefaultReasoningEffort("codex");
-  const reasoningLabelByOption: Record<CodexReasoningEffort, string> = {
+  const defaultReasoningEffort = getDefaultReasoningEffort(props.selectedProvider);
+  const reasoningLabelByOption: Record<ProviderReasoningEffort, string> = {
     low: "Low",
     medium: "Medium",
     high: "High",
     xhigh: "Extra High",
+    max: "Max",
+    ultrathink: "Ultrathink",
   };
 
   return (
@@ -57,10 +59,12 @@ export const CompactComposerControlsMenu = memo(function CompactComposerControls
         <EllipsisIcon aria-hidden="true" className="size-4" />
       </MenuTrigger>
       <MenuPopup align="start">
-        {props.selectedProvider === "codex" && props.selectedEffort != null ? (
+        {props.selectedEffort != null ? (
           <>
             <MenuGroup>
-              <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">Reasoning</div>
+              <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">
+                {props.selectedProvider === "codex" ? "Reasoning" : "Effort"}
+              </div>
               <MenuRadioGroup
                 value={props.selectedEffort}
                 onValueChange={(value) => {
@@ -78,20 +82,28 @@ export const CompactComposerControlsMenu = memo(function CompactComposerControls
                 ))}
               </MenuRadioGroup>
             </MenuGroup>
-            <MenuDivider />
-            <MenuGroup>
-              <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">Fast Mode</div>
-              <MenuRadioGroup
-                value={props.selectedCodexFastModeEnabled ? "on" : "off"}
-                onValueChange={(value) => {
-                  props.onCodexFastModeChange(value === "on");
-                }}
-              >
-                <MenuRadioItem value="off">off</MenuRadioItem>
-                <MenuRadioItem value="on">on</MenuRadioItem>
-              </MenuRadioGroup>
-            </MenuGroup>
-            <MenuDivider />
+            {props.selectedProvider === "codex" ? (
+              <>
+                <MenuDivider />
+                <MenuGroup>
+                  <div className="px-2 py-1.5 font-medium text-muted-foreground text-xs">
+                    Fast Mode
+                  </div>
+                  <MenuRadioGroup
+                    value={props.selectedCodexFastModeEnabled ? "on" : "off"}
+                    onValueChange={(value) => {
+                      props.onCodexFastModeChange(value === "on");
+                    }}
+                  >
+                    <MenuRadioItem value="off">off</MenuRadioItem>
+                    <MenuRadioItem value="on">on</MenuRadioItem>
+                  </MenuRadioGroup>
+                </MenuGroup>
+                <MenuDivider />
+              </>
+            ) : (
+              <MenuDivider />
+            )}
           </>
         ) : null}
         <MenuGroup>
diff --git a/apps/web/src/components/chat/ProviderHealthBanner.tsx b/apps/web/src/components/chat/ProviderHealthBanner.tsx
index 12c7f6054..9da45ba3f 100644
--- a/apps/web/src/components/chat/ProviderHealthBanner.tsx
+++ b/apps/web/src/components/chat/ProviderHealthBanner.tsx
@@ -12,18 +12,23 @@ export const ProviderHealthBanner = memo(function ProviderHealthBanner({
     return null;
   }
 
+  const providerLabel =
+    status.provider === "codex"
+      ? "Codex"
+      : status.provider === "claudeAgent"
+        ? "Claude"
+        : status.provider;
   const defaultMessage =
     status.status === "error"
-      ? `${status.provider} provider is unavailable.`
-      : `${status.provider} provider has limited availability.`;
+      ? `${providerLabel} provider is unavailable.`
+      : `${providerLabel} provider has limited availability.`;
+  const title = providerLabel === "Codex" ? "Codex provider status" : `${providerLabel} status`;
 
   return (
     <div className="pt-3 mx-auto max-w-3xl">
       <Alert variant={status.status === "error" ? "error" : "warning"}>
         <CircleAlertIcon />
-        <AlertTitle>
-          {status.provider === "codex" ? "Codex provider status" : `${status.provider} status`}
-        </AlertTitle>
+        <AlertTitle>{title}</AlertTitle>
         <AlertDescription className="line-clamp-3" title={status.message ?? defaultMessage}>
           {status.message ?? defaultMessage}
         </AlertDescription>
diff --git a/apps/web/src/components/chat/ProviderModelPicker.tsx b/apps/web/src/components/chat/ProviderModelPicker.tsx
index 0ffb46f8c..b384496ef 100644
--- a/apps/web/src/components/chat/ProviderModelPicker.tsx
+++ b/apps/web/src/components/chat/ProviderModelPicker.tsx
@@ -79,6 +79,7 @@ export const ProviderModelPicker = memo(function ProviderModelPicker(props: {
   model: ModelSlug;
   lockedProvider: ProviderKind | null;
   modelOptionsByProvider: Record<ProviderKind, ReadonlyArray<{ slug: string; name: string }>>;
+  ultrathinkActive?: boolean;
   compact?: boolean;
   disabled?: boolean;
   onProviderModelChange: (provider: ProviderKind, model: ModelSlug) => void;
@@ -129,7 +130,16 @@ export const ProviderModelPicker = memo(function ProviderModelPicker(props: {
         <span
           className={cn("flex min-w-0 items-center gap-2", props.compact ? "max-w-36" : undefined)}
         >
-          <ProviderIcon aria-hidden="true" className="size-4 shrink-0 text-muted-foreground/70" />
+          <ProviderIcon
+            aria-hidden="true"
+            className={cn(
+              "size-4 shrink-0",
+              props.provider === "claudeAgent" ? "text-[#d97757]" : "text-muted-foreground/70",
+              props.provider === "claudeAgent" && props.ultrathinkActive
+                ? "ultrathink-chroma"
+                : undefined,
+            )}
+          />
           <span className="truncate">{selectedModelLabel}</span>
           <ChevronDownIcon aria-hidden="true" className="size-3 opacity-60" />
         </span>
diff --git a/apps/web/src/composerDraftStore.ts b/apps/web/src/composerDraftStore.ts
index f86909c89..7ead0e270 100644
--- a/apps/web/src/composerDraftStore.ts
+++ b/apps/web/src/composerDraftStore.ts
@@ -1,11 +1,12 @@
 import {
+  CLAUDE_CODE_EFFORT_OPTIONS,
   DEFAULT_REASONING_EFFORT_BY_PROVIDER,
   ProjectId,
   REASONING_EFFORT_OPTIONS_BY_PROVIDER,
   ThreadId,
-  type CodexReasoningEffort,
   type ProviderKind,
   type ProviderInteractionMode,
+  type ProviderReasoningEffort,
   type RuntimeMode,
 } from "@t3tools/contracts";
 import { normalizeModelSlug } from "@t3tools/shared/model";
@@ -78,7 +79,7 @@ interface PersistedComposerThreadDraftState {
   model?: string | null;
   runtimeMode?: RuntimeMode | null;
   interactionMode?: ProviderInteractionMode | null;
-  effort?: CodexReasoningEffort | null;
+  effort?: ProviderReasoningEffort | null;
   codexFastMode?: boolean | null;
   serviceTier?: string | null;
 }
@@ -108,7 +109,7 @@ interface ComposerThreadDraftState {
   model: string | null;
   runtimeMode: RuntimeMode | null;
   interactionMode: ProviderInteractionMode | null;
-  effort: CodexReasoningEffort | null;
+  effort: ProviderReasoningEffort | null;
   codexFastMode: boolean;
 }
 
@@ -167,7 +168,7 @@ interface ComposerDraftStoreState {
     threadId: ThreadId,
     interactionMode: ProviderInteractionMode | null | undefined,
   ) => void;
-  setEffort: (threadId: ThreadId, effort: CodexReasoningEffort | null | undefined) => void;
+  setEffort: (threadId: ThreadId, effort: ProviderReasoningEffort | null | undefined) => void;
   setCodexFastMode: (threadId: ThreadId, enabled: boolean | null | undefined) => void;
   addImage: (threadId: ThreadId, image: ComposerImageAttachment) => void;
   addImages: (threadId: ThreadId, images: ComposerImageAttachment[]) => void;
@@ -206,9 +207,14 @@ const EMPTY_THREAD_DRAFT = Object.freeze({
   codexFastMode: false,
 }) as ComposerThreadDraftState;
 
-const REASONING_EFFORT_VALUES = new Set<CodexReasoningEffort>(
-  REASONING_EFFORT_OPTIONS_BY_PROVIDER.codex,
-);
+const REASONING_EFFORT_VALUES = new Set<ProviderReasoningEffort>([
+  ...REASONING_EFFORT_OPTIONS_BY_PROVIDER.codex,
+  ...CLAUDE_CODE_EFFORT_OPTIONS,
+]);
+const DEFAULT_REASONING_EFFORT_VALUES = new Set<ProviderReasoningEffort>([
+  DEFAULT_REASONING_EFFORT_BY_PROVIDER.codex,
+  DEFAULT_REASONING_EFFORT_BY_PROVIDER.claudeAgent,
+]);
 
 function createEmptyThreadDraft(): ComposerThreadDraftState {
   return {
@@ -421,8 +427,8 @@ function normalizePersistedComposerDraftState(value: unknown): PersistedComposer
     const effortCandidate =
       typeof draftCandidate.effort === "string" ? draftCandidate.effort : null;
     const effort =
-      effortCandidate && REASONING_EFFORT_VALUES.has(effortCandidate as CodexReasoningEffort)
-        ? (effortCandidate as CodexReasoningEffort)
+      effortCandidate && REASONING_EFFORT_VALUES.has(effortCandidate as ProviderReasoningEffort)
+        ? (effortCandidate as ProviderReasoningEffort)
         : null;
     const codexFastMode =
       draftCandidate.codexFastMode === true ||
@@ -934,7 +940,7 @@ export const useComposerDraftStore = create<ComposerDraftStoreState>()(
         const nextEffort =
           effort &&
           REASONING_EFFORT_VALUES.has(effort) &&
-          effort !== DEFAULT_REASONING_EFFORT_BY_PROVIDER.codex
+          !DEFAULT_REASONING_EFFORT_VALUES.has(effort)
             ? effort
             : null;
         set((state) => {
diff --git a/apps/web/src/index.css b/apps/web/src/index.css
index 228179161..ea76f24fa 100644
--- a/apps/web/src/index.css
+++ b/apps/web/src/index.css
@@ -404,3 +404,66 @@ label:has(> select#reasoning-effort) select {
   overflow: clip;
   background: color-mix(in srgb, var(--card) 92%, var(--background));
 }
+
+@keyframes ultrathink-rainbow {
+  0% {
+    background-position: 0% 50%;
+  }
+  100% {
+    background-position: 200% 50%;
+  }
+}
+
+@keyframes ultrathink-chroma-shift {
+  0% {
+    filter: hue-rotate(0deg) saturate(1.2);
+  }
+  100% {
+    filter: hue-rotate(360deg) saturate(1.2);
+  }
+}
+
+.ultrathink-frame {
+  --ultrathink-spectrum: linear-gradient(
+    120deg,
+    #ff6b6b 0%,
+    #f59e0b 18%,
+    #22c55e 36%,
+    #14b8a6 54%,
+    #3b82f6 72%,
+    #ec4899 90%,
+    #ff6b6b 100%
+  );
+  background-image: var(--ultrathink-spectrum);
+  background-size: 220% 220%;
+  animation: ultrathink-rainbow 10s linear infinite;
+}
+
+.ultrathink-chroma {
+  animation: ultrathink-chroma-shift 10s linear infinite;
+}
+
+.ultrathink-pill {
+  background:
+    linear-gradient(var(--card), var(--card)) padding-box,
+    var(--ultrathink-spectrum) border-box;
+  background-size:
+    100% 100%,
+    220% 220%;
+  background-position:
+    0 0,
+    0% 50%;
+  animation: ultrathink-rainbow 10s linear infinite;
+  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--card) 82%, transparent);
+}
+
+.ultrathink-word {
+  display: inline-block;
+  color: transparent;
+  background-image: var(--ultrathink-spectrum);
+  background-size: 220% 220%;
+  background-position: 0% 50%;
+  background-clip: text;
+  -webkit-background-clip: text;
+  animation: ultrathink-rainbow 10s linear infinite;
+}
diff --git a/packages/contracts/src/model.ts b/packages/contracts/src/model.ts
index 95f33e180..f417aeb41 100644
--- a/packages/contracts/src/model.ts
+++ b/packages/contracts/src/model.ts
@@ -3,6 +3,9 @@ import type { ProviderKind } from "./orchestration";
 
 export const CODEX_REASONING_EFFORT_OPTIONS = ["xhigh", "high", "medium", "low"] as const;
 export type CodexReasoningEffort = (typeof CODEX_REASONING_EFFORT_OPTIONS)[number];
+export const CLAUDE_CODE_EFFORT_OPTIONS = ["low", "medium", "high", "max", "ultrathink"] as const;
+export type ClaudeCodeEffort = (typeof CLAUDE_CODE_EFFORT_OPTIONS)[number];
+export type ProviderReasoningEffort = CodexReasoningEffort | ClaudeCodeEffort;
 
 export const CodexModelOptions = Schema.Struct({
   reasoningEffort: Schema.optional(Schema.Literals(CODEX_REASONING_EFFORT_OPTIONS)),
@@ -12,6 +15,7 @@ export type CodexModelOptions = typeof CodexModelOptions.Type;
 
 export const ClaudeModelOptions = Schema.Struct({
   thinking: Schema.optional(Schema.Boolean),
+  effort: Schema.optional(Schema.Literals(CLAUDE_CODE_EFFORT_OPTIONS)),
 });
 export type ClaudeModelOptions = typeof ClaudeModelOptions.Type;
 
@@ -80,10 +84,10 @@ export const MODEL_SLUG_ALIASES_BY_PROVIDER: Record<ProviderKind, Record<string,
 
 export const REASONING_EFFORT_OPTIONS_BY_PROVIDER = {
   codex: CODEX_REASONING_EFFORT_OPTIONS,
-  claudeAgent: [],
-} as const satisfies Record<ProviderKind, readonly CodexReasoningEffort[]>;
+  claudeAgent: CLAUDE_CODE_EFFORT_OPTIONS,
+} as const satisfies Record<ProviderKind, readonly ProviderReasoningEffort[]>;
 
 export const DEFAULT_REASONING_EFFORT_BY_PROVIDER = {
   codex: "high",
-  claudeAgent: null,
-} as const satisfies Record<ProviderKind, CodexReasoningEffort | null>;
+  claudeAgent: "high",
+} as const satisfies Record<ProviderKind, ProviderReasoningEffort>;
diff --git a/packages/contracts/src/provider.test.ts b/packages/contracts/src/provider.test.ts
index de0ac36b9..87c866e88 100644
--- a/packages/contracts/src/provider.test.ts
+++ b/packages/contracts/src/provider.test.ts
@@ -49,6 +49,12 @@ describe("ProviderSessionStartInput", () => {
       provider: "claudeAgent",
       cwd: "/tmp/workspace",
       model: "claude-sonnet-4-6",
+      modelOptions: {
+        claudeAgent: {
+          thinking: true,
+          effort: "max",
+        },
+      },
       providerOptions: {
         claudeAgent: {
           binaryPath: "/usr/local/bin/claude",
@@ -59,6 +65,8 @@ describe("ProviderSessionStartInput", () => {
       runtimeMode: "full-access",
     });
     expect(parsed.provider).toBe("claudeAgent");
+    expect(parsed.modelOptions?.claudeAgent?.thinking).toBe(true);
+    expect(parsed.modelOptions?.claudeAgent?.effort).toBe("max");
     expect(parsed.providerOptions?.claudeAgent?.binaryPath).toBe("/usr/local/bin/claude");
     expect(parsed.providerOptions?.claudeAgent?.permissionMode).toBe("plan");
     expect(parsed.providerOptions?.claudeAgent?.maxThinkingTokens).toBe(12_000);
@@ -83,4 +91,18 @@ describe("ProviderSendTurnInput", () => {
     expect(parsed.modelOptions?.codex?.reasoningEffort).toBe("xhigh");
     expect(parsed.modelOptions?.codex?.fastMode).toBe(true);
   });
+
+  it("accepts claude provider effort options including ultrathink", () => {
+    const parsed = decodeProviderSendTurnInput({
+      threadId: "thread-1",
+      model: "claude-sonnet-4-6",
+      modelOptions: {
+        claudeAgent: {
+          effort: "ultrathink",
+        },
+      },
+    });
+
+    expect(parsed.modelOptions?.claudeAgent?.effort).toBe("ultrathink");
+  });
 });
diff --git a/packages/contracts/src/providerRuntime.ts b/packages/contracts/src/providerRuntime.ts
index c7df3da40..2fec889b6 100644
--- a/packages/contracts/src/providerRuntime.ts
+++ b/packages/contracts/src/providerRuntime.ts
@@ -439,6 +439,7 @@ export type TaskStartedPayload = typeof TaskStartedPayload.Type;
 const TaskProgressPayload = Schema.Struct({
   taskId: RuntimeTaskId,
   description: TrimmedNonEmptyStringSchema,
+  summary: Schema.optional(TrimmedNonEmptyStringSchema),
   usage: Schema.optional(Schema.Unknown),
   lastToolName: Schema.optional(TrimmedNonEmptyStringSchema),
 });
diff --git a/packages/shared/src/model.test.ts b/packages/shared/src/model.test.ts
index 21c6ae585..08f0b71f5 100644
--- a/packages/shared/src/model.test.ts
+++ b/packages/shared/src/model.test.ts
@@ -9,12 +9,15 @@ import {
 } from "@t3tools/contracts";
 
 import {
+  applyClaudePromptEffortPrefix,
+  getEffectiveClaudeCodeEffort,
   getDefaultModel,
   getDefaultReasoningEffort,
   getModelOptions,
   getReasoningEffortOptions,
   inferProviderForModel,
   normalizeModelSlug,
+  resolveReasoningEffortForProvider,
   resolveModelSlug,
   resolveModelSlugForProvider,
 } from "./model";
@@ -88,8 +91,14 @@ describe("getReasoningEffortOptions", () => {
     expect(getReasoningEffortOptions("codex")).toEqual(REASONING_EFFORT_OPTIONS_BY_PROVIDER.codex);
   });
 
-  it("returns no reasoning options for claudeAgent", () => {
-    expect(getReasoningEffortOptions("claudeAgent")).toEqual([]);
+  it("returns claude effort options for claudeAgent", () => {
+    expect(getReasoningEffortOptions("claudeAgent")).toEqual([
+      "low",
+      "medium",
+      "high",
+      "max",
+      "ultrathink",
+    ]);
   });
 });
 
@@ -118,3 +127,42 @@ describe("getDefaultReasoningEffort", () => {
     );
   });
 });
+
+describe("resolveReasoningEffortForProvider", () => {
+  it("accepts provider-scoped effort values", () => {
+    expect(resolveReasoningEffortForProvider("codex", "xhigh")).toBe("xhigh");
+    expect(resolveReasoningEffortForProvider("claudeAgent", "ultrathink")).toBe("ultrathink");
+  });
+
+  it("rejects effort values from the wrong provider", () => {
+    expect(resolveReasoningEffortForProvider("codex", "max")).toBeNull();
+    expect(resolveReasoningEffortForProvider("claudeAgent", "xhigh")).toBeNull();
+  });
+});
+
+describe("applyClaudePromptEffortPrefix", () => {
+  it("prefixes ultrathink prompts exactly once", () => {
+    expect(applyClaudePromptEffortPrefix("Investigate this", "ultrathink")).toBe(
+      "Ultrathink:\nInvestigate this",
+    );
+    expect(applyClaudePromptEffortPrefix("Ultrathink:\nInvestigate this", "ultrathink")).toBe(
+      "Ultrathink:\nInvestigate this",
+    );
+  });
+
+  it("leaves non-ultrathink prompts unchanged", () => {
+    expect(applyClaudePromptEffortPrefix("Investigate this", "high")).toBe("Investigate this");
+  });
+});
+
+describe("getEffectiveClaudeCodeEffort", () => {
+  it("maps ultrathink to max for Claude runtime configuration", () => {
+    expect(getEffectiveClaudeCodeEffort("ultrathink")).toBe("max");
+    expect(getEffectiveClaudeCodeEffort("high")).toBe("high");
+  });
+
+  it("returns null when no claude effort is selected", () => {
+    expect(getEffectiveClaudeCodeEffort(null)).toBeNull();
+    expect(getEffectiveClaudeCodeEffort(undefined)).toBeNull();
+  });
+});
diff --git a/packages/shared/src/model.ts b/packages/shared/src/model.ts
index cd1d043ca..7468b50b2 100644
--- a/packages/shared/src/model.ts
+++ b/packages/shared/src/model.ts
@@ -1,12 +1,15 @@
 import {
+  CLAUDE_CODE_EFFORT_OPTIONS,
   CODEX_REASONING_EFFORT_OPTIONS,
   DEFAULT_MODEL_BY_PROVIDER,
   DEFAULT_REASONING_EFFORT_BY_PROVIDER,
   MODEL_OPTIONS_BY_PROVIDER,
   MODEL_SLUG_ALIASES_BY_PROVIDER,
   REASONING_EFFORT_OPTIONS_BY_PROVIDER,
+  type ClaudeCodeEffort,
   type CodexReasoningEffort,
   type ModelSlug,
+  type ProviderReasoningEffort,
   type ProviderKind,
 } from "@t3tools/contracts";
 
@@ -81,18 +84,79 @@ export function inferProviderForModel(
   return typeof model === "string" && model.trim().startsWith("claude-") ? "claudeAgent" : fallback;
 }
 
+export function getReasoningEffortOptions(provider: "codex"): ReadonlyArray<CodexReasoningEffort>;
+export function getReasoningEffortOptions(provider: "claudeAgent"): ReadonlyArray<ClaudeCodeEffort>;
+export function getReasoningEffortOptions(
+  provider?: ProviderKind,
+): ReadonlyArray<ProviderReasoningEffort>;
 export function getReasoningEffortOptions(
   provider: ProviderKind = "codex",
-): ReadonlyArray<CodexReasoningEffort> {
+): ReadonlyArray<ProviderReasoningEffort> {
   return REASONING_EFFORT_OPTIONS_BY_PROVIDER[provider];
 }
 
 export function getDefaultReasoningEffort(provider: "codex"): CodexReasoningEffort;
-export function getDefaultReasoningEffort(provider: ProviderKind): CodexReasoningEffort | null;
+export function getDefaultReasoningEffort(provider: "claudeAgent"): ClaudeCodeEffort;
+export function getDefaultReasoningEffort(provider?: ProviderKind): ProviderReasoningEffort;
 export function getDefaultReasoningEffort(
   provider: ProviderKind = "codex",
-): CodexReasoningEffort | null {
+): ProviderReasoningEffort {
   return DEFAULT_REASONING_EFFORT_BY_PROVIDER[provider];
 }
 
-export { CODEX_REASONING_EFFORT_OPTIONS };
+export function resolveReasoningEffortForProvider(
+  provider: "codex",
+  effort: string | null | undefined,
+): CodexReasoningEffort | null;
+export function resolveReasoningEffortForProvider(
+  provider: "claudeAgent",
+  effort: string | null | undefined,
+): ClaudeCodeEffort | null;
+export function resolveReasoningEffortForProvider(
+  provider: ProviderKind,
+  effort: string | null | undefined,
+): ProviderReasoningEffort | null;
+export function resolveReasoningEffortForProvider(
+  provider: ProviderKind,
+  effort: string | null | undefined,
+): ProviderReasoningEffort | null {
+  if (typeof effort !== "string") {
+    return null;
+  }
+
+  const trimmed = effort.trim();
+  if (!trimmed) {
+    return null;
+  }
+
+  const options = REASONING_EFFORT_OPTIONS_BY_PROVIDER[provider] as ReadonlyArray<string>;
+  return options.includes(trimmed) ? (trimmed as ProviderReasoningEffort) : null;
+}
+
+export function getEffectiveClaudeCodeEffort(
+  effort: ClaudeCodeEffort | null | undefined,
+): Exclude<ClaudeCodeEffort, "ultrathink"> | null {
+  if (!effort) {
+    return null;
+  }
+  return effort === "ultrathink" ? "max" : effort;
+}
+
+export function applyClaudePromptEffortPrefix(
+  text: string,
+  effort: ClaudeCodeEffort | null | undefined,
+): string {
+  const trimmed = text.trim();
+  if (!trimmed) {
+    return trimmed;
+  }
+  if (effort !== "ultrathink") {
+    return trimmed;
+  }
+  if (trimmed.startsWith("Ultrathink:")) {
+    return trimmed;
+  }
+  return `Ultrathink:\n${trimmed}`;
+}
+
+export { CLAUDE_CODE_EFFORT_OPTIONS, CODEX_REASONING_EFFORT_OPTIONS };