diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 842f8484eb..510b2c73be 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -24,3 +24,15 @@ repos:
         entry: make lint-web
         language: system
         pass_filenames: false
+
+      - id: web-typecheck
+        name: Web typecheck
+        entry: make typecheck-web
+        language: system
+        pass_filenames: false
+
+      - id: typecheck
+        name: Typecheck all apps
+        entry: make typecheck
+        language: system
+        pass_filenames: false
diff --git a/Makefile b/Makefile
index fd0b752dc2..b97bdebc53 100644
--- a/Makefile
+++ b/Makefile
@@ -198,6 +198,16 @@ fmt-web:
 	@echo "Formatting web code..."
 	@cd $(APPS_DIR) && $(PNPM) --filter @kandev/web lint -- --fix || true
 
+.PHONY: typecheck-web
+typecheck-web:
+	@echo "Type-checking web app..."
+	@cd $(APPS_DIR) && $(PNPM) --filter @kandev/web exec tsc -p tsconfig.json --noEmit
+
+.PHONY: typecheck
+typecheck:
+	@echo "Type-checking all apps..."
+	@cd $(APPS_DIR) && $(PNPM) -r exec tsc -p tsconfig.json --noEmit
+
 #
 # Cleanup
 #
diff --git a/apps/backend/cmd/kandev/main.go b/apps/backend/cmd/kandev/main.go
index b5dcbd2c53..653bb68b80 100644
--- a/apps/backend/cmd/kandev/main.go
+++ b/apps/backend/cmd/kandev/main.go
@@ -159,13 +159,14 @@ func main() {
 		log.Warn("Failed to initialize Docker client - agent features will be disabled", zap.Error(err))
 		dockerClient = nil
 	} else {
-		defer func() {
-			_ = dockerClient.Close()
-		}()
 		if err := dockerClient.Ping(ctx); err != nil {
 			log.Warn("Docker daemon not available - agent features will be disabled", zap.Error(err))
+			_ = dockerClient.Close()
 			dockerClient = nil
 		} else {
+			defer func() {
+				_ = dockerClient.Close()
+			}()
 			log.Info("Connected to Docker daemon")
 		}
 	}
diff --git a/apps/web/components/kanban-with-preview.tsx b/apps/web/components/kanban-with-preview.tsx
index 542dba75d9..bebbad2e45 100644
--- a/apps/web/components/kanban-with-preview.tsx
+++ b/apps/web/components/kanban-with-preview.tsx
@@ -45,7 +45,7 @@ export function KanbanWithPreview() {
       state: task.state,
       description: task.description,
       position: task.position,
-      repositoryUrl: task.repositoryUrl,
+      repositoryId: task.repositoryId,
     };
   }, [selectedTaskId, kanbanTasks]);
 
diff --git a/apps/web/components/task-preview-panel.tsx b/apps/web/components/task-preview-panel.tsx
index 8c90383c04..7622940f92 100644
--- a/apps/web/components/task-preview-panel.tsx
+++ b/apps/web/components/task-preview-panel.tsx
@@ -4,6 +4,8 @@ import { IconX, IconCircleCheck, IconCircleX, IconLoader2, IconAlertTriangle, Ic
 import { Button } from "@kandev/ui/button";
 import { Badge } from "@kandev/ui/badge";
 import { getRepositoryDisplayName } from "@/lib/utils";
+import { useAppStore } from "@/components/state-provider";
+import { useMemo } from "react";
 import type { Task } from "./kanban-card";
 
 interface TaskPreviewPanelProps {
@@ -66,6 +68,15 @@ function getStateDisplay(state?: string) {
 }
 
 export function TaskPreviewPanel({ task, onClose, onMaximize }: TaskPreviewPanelProps) {
+  const repositoriesByWorkspace = useAppStore((state) => state.repositories.itemsByWorkspaceId);
+  const repository = useMemo(() => {
+    if (!task?.repositoryId) return null;
+    return Object.values(repositoriesByWorkspace)
+      .flat()
+      .find((repo) => repo.id === task.repositoryId) ?? null;
+  }, [repositoriesByWorkspace, task]);
+  const repoName = getRepositoryDisplayName(repository?.local_path);
+
   if (!task) {
     return (
       <div className="flex h-full w-full flex-col border-l bg-background">
@@ -83,7 +94,6 @@ export function TaskPreviewPanel({ task, onClose, onMaximize }: TaskPreviewPanel
     );
   }
 
-  const repoName = getRepositoryDisplayName(task.repositoryUrl);
   const stateDisplay = getStateDisplay(task.state);
 
   return (
diff --git a/apps/web/components/task/chat/message-renderer.tsx b/apps/web/components/task/chat/message-renderer.tsx
index 12f2d3152e..fa38503636 100644
--- a/apps/web/components/task/chat/message-renderer.tsx
+++ b/apps/web/components/task/chat/message-renderer.tsx
@@ -1,5 +1,6 @@
 'use client';
 
+import type { ReactElement } from 'react';
 import type { Message } from '@/lib/types/http';
 import { ChatMessage } from '@/components/task/chat/messages/chat-message';
 import { StatusMessage } from '@/components/task/chat/messages/status-message';
@@ -13,7 +14,7 @@ type AdapterContext = {
 
 type MessageAdapter = {
   matches: (comment: Message, ctx: AdapterContext) => boolean;
-  render: (comment: Message, ctx: AdapterContext) => JSX.Element;
+  render: (comment: Message, ctx: AdapterContext) => ReactElement;
 };
 
 const adapters: MessageAdapter[] = [
diff --git a/apps/web/components/task/chat/messages/rich-blocks.tsx b/apps/web/components/task/chat/messages/rich-blocks.tsx
index a2fd32a826..d9c4380c25 100644
--- a/apps/web/components/task/chat/messages/rich-blocks.tsx
+++ b/apps/web/components/task/chat/messages/rich-blocks.tsx
@@ -13,13 +13,13 @@ function resolveDiffPayload(diff: unknown): DiffPayload | null {
     return null;
   }
   if (Array.isArray(diff)) {
-    return { hunks: diff };
+    return { hunks: diff.map((hunk) => String(hunk)) };
   }
   if (typeof diff === 'object' && diff !== null) {
     const candidate = diff as Partial<DiffPayload>;
     if (Array.isArray(candidate.hunks)) {
       return {
-        hunks: candidate.hunks,
+        hunks: candidate.hunks.map((hunk) => String(hunk)),
         oldFile: candidate.oldFile,
         newFile: candidate.newFile,
       };
diff --git a/apps/web/components/task/chat/types.ts b/apps/web/components/task/chat/types.ts
index 1c7a0ba7b5..74b6c447ab 100644
--- a/apps/web/components/task/chat/types.ts
+++ b/apps/web/components/task/chat/types.ts
@@ -27,7 +27,7 @@ export type RichMetadata = {
 };
 
 export type DiffPayload = {
-  hunks: unknown[];
+  hunks: string[];
   oldFile?: { fileName?: string; fileLang?: string };
   newFile?: { fileName?: string; fileLang?: string };
 };
diff --git a/apps/web/components/task/task-chat-panel.tsx b/apps/web/components/task/task-chat-panel.tsx
index 22c03ef435..50bb71b375 100644
--- a/apps/web/components/task/task-chat-panel.tsx
+++ b/apps/web/components/task/task-chat-panel.tsx
@@ -177,7 +177,6 @@ export function TaskChatPanel({
     const trimmed = messageInput.trim();
     if (!trimmed || isSending) return;
     setIsSending(true);
-    setIsAwaitingResponse(true);
     flushSync(() => {
       setMessageInput('');
     });
diff --git a/apps/web/hooks/use-kanban-preview.ts b/apps/web/hooks/use-kanban-preview.ts
index 94a8d6d533..9eec2eaf00 100644
--- a/apps/web/hooks/use-kanban-preview.ts
+++ b/apps/web/hooks/use-kanban-preview.ts
@@ -12,7 +12,7 @@ export function useKanbanPreview(options: UseKanbanPreviewOptions = {}) {
   // Always start with default values to avoid hydration mismatch
   const [selectedTaskId, setSelectedTaskId] = useState<string | null>(null);
   const [isOpen, setIsOpen] = useState(false);
-  const [previewWidthPx, setPreviewWidthPx] = useState(PREVIEW_PANEL.DEFAULT_WIDTH_PX);
+  const [previewWidthPx, setPreviewWidthPx] = useState<number>(PREVIEW_PANEL.DEFAULT_WIDTH_PX);
   const containerRef = useRef<HTMLDivElement | null>(null);
 
   // Load persisted state from localStorage AFTER hydration
diff --git a/apps/web/hooks/use-task-messages.ts b/apps/web/hooks/use-task-messages.ts
index b14c446e68..9003d1e6d5 100644
--- a/apps/web/hooks/use-task-messages.ts
+++ b/apps/web/hooks/use-task-messages.ts
@@ -1,8 +1,7 @@
 import { useEffect, useRef, useState } from 'react';
 import { getWebSocketClient } from '@/lib/ws/connection';
 import { useAppStore, useAppStoreApi } from '@/components/state-provider';
-import type { Message } from '@/lib/types/http';
-import type { AgentSessionState } from '@/lib/types/http';
+import type { AgentSessionState, Message } from '@/lib/types/http';
 
 interface UseTaskMessagesReturn {
   isLoading: boolean;
@@ -130,8 +129,8 @@ export function useTaskMessages(
     if (!agentSessionId || !agentSessionState || !taskId) return;
     if (hasAgentMessage) return;
 
-    const terminalStates: AgentSessionState[] = ['WAITING_FOR_INPUT', 'COMPLETED', 'FAILED'];
-    if (!terminalStates.includes(agentSessionState)) {
+    const terminalStates = new Set<AgentSessionState>(['WAITING_FOR_INPUT', 'COMPLETED', 'FAILED']);
+    if (!terminalStates.has(agentSessionState)) {
       return;
     }
 
diff --git a/apps/web/lib/keyboard/constants.test.ts b/apps/web/lib/keyboard/constants.test.ts
index 9b7cf83c9a..e9d76631d4 100644
--- a/apps/web/lib/keyboard/constants.test.ts
+++ b/apps/web/lib/keyboard/constants.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { MODIFIER_KEYS, KEYS, SHORTCUTS } from './constants';
+import { MODIFIER_KEYS, KEYS, SHORTCUTS, KeyboardShortcut } from './constants';
 
 describe('MODIFIER_KEYS', () => {
   it('defines all modifier keys', () => {
@@ -69,8 +69,9 @@ describe('SHORTCUTS', () => {
 
   describe('CANCEL', () => {
     it('uses Escape key without modifiers', () => {
-      expect(SHORTCUTS.CANCEL.key).toBe('Escape');
-      expect(SHORTCUTS.CANCEL.modifiers).toBeUndefined();
+      const cancel = SHORTCUTS.CANCEL as KeyboardShortcut;
+      expect(cancel.key).toBe('Escape');
+      expect(cancel.modifiers).toBeUndefined();
     });
   });
 
@@ -110,9 +111,10 @@ describe('SHORTCUTS', () => {
 
   it('all shortcuts with modifiers have valid modifier properties', () => {
     Object.values(SHORTCUTS).forEach((shortcut) => {
-      if (shortcut.modifiers) {
+      const typedShortcut = shortcut as KeyboardShortcut;
+      if (typedShortcut.modifiers) {
         const validModifiers = ['ctrl', 'cmd', 'alt', 'shift', 'ctrlOrCmd'];
-        Object.keys(shortcut.modifiers).forEach((modifier) => {
+        Object.keys(typedShortcut.modifiers).forEach((modifier) => {
           expect(validModifiers).toContain(modifier);
         });
       }
@@ -141,4 +143,3 @@ describe('Type definitions', () => {
     expect(shortcut3.modifiers?.ctrl).toBe(true);
   });
 });
-
diff --git a/apps/web/lib/state/store.ts b/apps/web/lib/state/store.ts
index 047ebadf6e..83140d103a 100644
--- a/apps/web/lib/state/store.ts
+++ b/apps/web/lib/state/store.ts
@@ -2,6 +2,7 @@ import type { ReactNode } from 'react';
 import type {
   Agent,
   AgentDiscovery,
+  AgentSessionState,
   Branch,
   Environment,
   Executor,
@@ -171,7 +172,7 @@ export type AppState = {
   gitStatus: GitStatusState;
   connection: ConnectionState;
   messages: MessagesState;
-  agentSessionStatesByTaskId: Record<string, string>;
+  agentSessionStatesByTaskId: Record<string, AgentSessionState>;
   hydrate: (state: Partial<AppState>) => void;
   setActiveWorkspace: (workspaceId: string | null) => void;
   setWorkspaces: (workspaces: WorkspaceState['items']) => void;
@@ -201,7 +202,7 @@ export type AppState = {
   prependMessages: (messages: Message[], meta?: { hasMore?: boolean; oldestCursor?: string | null }) => void;
   setMessagesMetadata: (meta: { hasMore?: boolean; isLoading?: boolean; oldestCursor?: string | null }) => void;
   setMessagesLoading: (loading: boolean) => void;
-  setAgentSessionState: (taskId: string, state: string) => void;
+  setAgentSessionState: (taskId: string, state: AgentSessionState) => void;
   setGitStatus: (taskId: string, gitStatus: Omit<GitStatusState, 'taskId'>) => void;
   clearGitStatus: () => void;
   bumpAgentProfilesVersion: () => void;
diff --git a/apps/web/lib/ws/handlers/agent-session.ts b/apps/web/lib/ws/handlers/agent-session.ts
index 224c88820a..e0f1e635e1 100644
--- a/apps/web/lib/ws/handlers/agent-session.ts
+++ b/apps/web/lib/ws/handlers/agent-session.ts
@@ -1,6 +1,7 @@
 import type { StoreApi } from 'zustand';
 import type { AppState } from '@/lib/state/store';
 import type { WsHandlers } from '@/lib/ws/handlers/types';
+import type { AgentSessionState } from '@/lib/types/http';
 
 export function registerAgentSessionHandlers(store: StoreApi<AppState>): WsHandlers {
   return {
@@ -9,7 +10,7 @@ export function registerAgentSessionHandlers(store: StoreApi<AppState>): WsHandl
       if (!payload?.task_id || !payload?.new_state) {
         return;
       }
-      store.getState().setAgentSessionState(payload.task_id, payload.new_state);
+      store.getState().setAgentSessionState(payload.task_id, payload.new_state as AgentSessionState);
     },
   };
 }