diff --git a/.vscode/settings.json b/.vscode/settings.json
index 4e0d5b7..c3b651b 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -7,7 +7,27 @@
   "biome.enabled": true,
   // autofix
   "editor.formatOnSave": false,
-  "[typescript][typescriptreact][javascript][javascriptreact][json][jsonc][json][yaml]": {
+  "[typescript]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "biomejs.biome"
+  },
+  "[typescriptreact]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "biomejs.biome"
+  },
+  "[javascript]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "biomejs.biome"
+  },
+  "[javascriptreact]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "biomejs.biome"
+  },
+  "[json]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "biomejs.biome"
+  },
+  "[jsonc]": {
     "editor.formatOnSave": true,
     "editor.defaultFormatter": "biomejs.biome"
   },
diff --git a/src/app/projects/[projectId]/components/chatForm/useChatMutations.ts b/src/app/projects/[projectId]/components/chatForm/useChatMutations.ts
index 88e0b2d..72d49ab 100644
--- a/src/app/projects/[projectId]/components/chatForm/useChatMutations.ts
+++ b/src/app/projects/[projectId]/components/chatForm/useChatMutations.ts
@@ -32,13 +32,7 @@ export const useNewChatMutation = (
     },
     onSuccess: async (response) => {
       onSuccess?.();
-      router.push(
-        `/projects/${projectId}/sessions/${response.sessionId}` +
-          response.userMessageId !==
-          undefined
-          ? `#message-${response.userMessageId}`
-          : "",
-      );
+      router.push(`/projects/${projectId}/sessions/${response.sessionId}`);
     },
   });
 };
@@ -70,9 +64,7 @@ export const useResumeChatMutation = (projectId: string, sessionId: string) => {
     },
     onSuccess: async (response) => {
       if (sessionId !== response.sessionId) {
-        router.push(
-          `/projects/${projectId}/sessions/${response.sessionId}#message-${response.userMessageId}`,
-        );
+        router.push(`/projects/${projectId}/sessions/${response.sessionId}`);
       }
     },
   });
diff --git a/src/server/hono/initialize.ts b/src/server/hono/initialize.ts
index d0d79a0..2b32e02 100644
--- a/src/server/hono/initialize.ts
+++ b/src/server/hono/initialize.ts
@@ -27,13 +27,13 @@ export const initialize = async (deps: {
 
     console.log("Initializing sessions cache");
     const results = await Promise.all(
-      projects.map((project) => deps.sessionRepository.getSessions(project.id))
+      projects.map((project) => deps.sessionRepository.getSessions(project.id)),
     );
     console.log(
       `${results.reduce(
         (s, { sessions }) => s + sessions.length,
-        0
-      )} sessions cache initialized`
+        0,
+      )} sessions cache initialized`,
     );
   } catch {
     // do nothing
diff --git a/src/server/hono/route.ts b/src/server/hono/route.ts
index e033cc9..c437935 100644
--- a/src/server/hono/route.ts
+++ b/src/server/hono/route.ts
@@ -337,7 +337,6 @@ export const routes = async (app: HonoAppType) => {
           return c.json({
             taskId: task.id,
             sessionId: task.sessionId,
-            userMessageId: task.userMessageId,
           });
         },
       )
@@ -373,7 +372,6 @@ export const routes = async (app: HonoAppType) => {
           return c.json({
             taskId: task.id,
             sessionId: task.sessionId,
-            userMessageId: task.userMessageId,
           });
         },
       )
@@ -385,7 +383,6 @@ export const routes = async (app: HonoAppType) => {
               id: task.id,
               status: task.status,
               sessionId: task.sessionId,
-              userMessageId: task.userMessageId,
             }),
           ),
         });
diff --git a/src/server/lib/storage/FileCacheStorage.ts b/src/server/lib/storage/FileCacheStorage.ts
index 34d71fc..ed333e9 100644
--- a/src/server/lib/storage/FileCacheStorage.ts
+++ b/src/server/lib/storage/FileCacheStorage.ts
@@ -13,7 +13,7 @@ export class FileCacheStorage<const T> {
 
   public static load<const LoadSchema>(
     key: string,
-    schema: z.ZodType<LoadSchema>
+    schema: z.ZodType<LoadSchema>,
   ) {
     const instance = new FileCacheStorage<LoadSchema>(key);
 
diff --git a/src/server/lib/storage/InMemoryCacheStorage.ts b/src/server/lib/storage/InMemoryCacheStorage.ts
index 5433d07..8f19e5e 100644
--- a/src/server/lib/storage/InMemoryCacheStorage.ts
+++ b/src/server/lib/storage/InMemoryCacheStorage.ts
@@ -1,8 +1,6 @@
 export class InMemoryCacheStorage<const T> {
   private storage = new Map<string, T>();
 
-  public constructor() {}
-
   public get(key: string) {
     return this.storage.get(key);
   }
diff --git a/src/server/service/claude-code/ClaudeCodeExecutor.ts b/src/server/service/claude-code/ClaudeCodeExecutor.ts
index d3c1678..b9de1b2 100644
--- a/src/server/service/claude-code/ClaudeCodeExecutor.ts
+++ b/src/server/service/claude-code/ClaudeCodeExecutor.ts
@@ -23,13 +23,17 @@ export class ClaudeCodeExecutor {
     );
   }
 
-  public get features() {
+  public get version() {
+    return this.claudeCodeVersion?.version;
+  }
+
+  public get availableFeatures() {
     return {
-      enableToolApproval:
+      canUseTool:
         this.claudeCodeVersion?.greaterThanOrEqual(
           new ClaudeCodeVersion({ major: 1, minor: 0, patch: 82 }),
         ) ?? false,
-      extractUuidFromSDKMessage:
+      uuidOnSDKMessage:
         this.claudeCodeVersion?.greaterThanOrEqual(
           new ClaudeCodeVersion({ major: 1, minor: 0, patch: 86 }),
         ) ?? false,
@@ -44,7 +48,7 @@ export class ClaudeCodeExecutor {
       options: {
         pathToClaudeCodeExecutable: this.pathToClaudeCodeExecutable,
         ...baseOptions,
-        ...(this.features.enableToolApproval ? { canUseTool } : {}),
+        ...(this.availableFeatures.canUseTool ? { canUseTool } : {}),
       },
     });
   }
diff --git a/src/server/service/claude-code/ClaudeCodeTaskController.ts b/src/server/service/claude-code/ClaudeCodeTaskController.ts
index 765f026..f7ad96c 100644
--- a/src/server/service/claude-code/ClaudeCodeTaskController.ts
+++ b/src/server/service/claude-code/ClaudeCodeTaskController.ts
@@ -2,6 +2,7 @@ import prexit from "prexit";
 import { ulid } from "ulid";
 import type { Config } from "../../config/config";
 import { eventBus } from "../events/EventBus";
+import { predictSessionsDatabase } from "../session/PredictSessionsDatabase";
 import { ClaudeCodeExecutor } from "./ClaudeCodeExecutor";
 import { createMessageGenerator } from "./createMessageGenerator";
 import type {
@@ -168,9 +169,20 @@ export class ClaudeCodeTaskController {
     );
 
     if (existingTask) {
+      console.log(
+        `Alive task for session(id=${currentSession.sessionId}) continued.`,
+      );
       const result = await this.continueTask(existingTask, message);
       return result;
     } else {
+      if (currentSession.sessionId === undefined) {
+        console.log(`New task started.`);
+      } else {
+        console.log(
+          `New task started for existing session(id=${currentSession.sessionId}).`,
+        );
+      }
+
       const result = await this.startTask(currentSession, message);
       return result;
     }
@@ -188,7 +200,7 @@ export class ClaudeCodeTaskController {
       projectId: string;
       sessionId?: string;
     },
-    message: string,
+    userMessage: string,
   ) {
     const {
       generateMessages,
@@ -196,7 +208,7 @@ export class ClaudeCodeTaskController {
       setFirstMessagePromise,
       resolveFirstMessage,
       awaitFirstMessage,
-    } = createMessageGenerator(message);
+    } = createMessageGenerator(userMessage);
 
     const task: PendingClaudeCodeTask = {
       status: "pending",
@@ -252,43 +264,62 @@ export class ClaudeCodeTaskController {
             });
           }
 
-          // 初回の system message だとまだ history ファイルが作成されていないので
-          if (message.type === "user" || message.type === "assistant") {
-            // 本来は message.uuid の存在チェックをしたいが、古いバージョンでは存在しないことがある
-            if (!resolved) {
-              console.log(
-                "[DEBUG startTask] 10. Resolving task for first time",
-              );
-
-              const runningTask: RunningClaudeCodeTask = {
-                status: "running",
-                id: task.id,
-                projectId: task.projectId,
-                cwd: task.cwd,
-                generateMessages: task.generateMessages,
-                setNextMessage: task.setNextMessage,
-                resolveFirstMessage: task.resolveFirstMessage,
-                setFirstMessagePromise: task.setFirstMessagePromise,
-                awaitFirstMessage: task.awaitFirstMessage,
-                onMessageHandlers: task.onMessageHandlers,
-                userMessageId: message.uuid,
-                sessionId: message.session_id,
-                abortController: abortController,
-              };
-              this.tasks.push(runningTask);
-              console.log(
-                "[DEBUG startTask] 11. About to call aliveTaskResolve",
-              );
-              aliveTaskResolve(runningTask);
-              resolved = true;
-              console.log(
-                "[DEBUG startTask] 12. aliveTaskResolve called, resolved=true",
-              );
-            }
-
-            resolveFirstMessage();
+          if (
+            message.type === "system" &&
+            message.subtype === "init" &&
+            currentSession.sessionId === undefined
+          ) {
+            // because it takes time for the Claude Code file to be updated, simulate the message
+            predictSessionsDatabase.createPredictSession({
+              id: message.session_id,
+              jsonlFilePath: message.session_id,
+              conversations: [
+                {
+                  type: "user",
+                  message: {
+                    role: "user",
+                    content: userMessage,
+                  },
+                  isSidechain: false,
+                  userType: "external",
+                  cwd: message.cwd,
+                  sessionId: message.session_id,
+                  version: this.claudeCode.version?.toString() ?? "unknown",
+                  uuid: message.uuid,
+                  timestamp: new Date().toISOString(),
+                  parentUuid: null,
+                },
+              ],
+              meta: {
+                firstCommand: null,
+                lastModifiedAt: new Date().toISOString(),
+                messageCount: 0,
+              },
+            });
           }
 
+          if (!resolved) {
+            const runningTask: RunningClaudeCodeTask = {
+              status: "running",
+              id: task.id,
+              projectId: task.projectId,
+              cwd: task.cwd,
+              generateMessages: task.generateMessages,
+              setNextMessage: task.setNextMessage,
+              resolveFirstMessage: task.resolveFirstMessage,
+              setFirstMessagePromise: task.setFirstMessagePromise,
+              awaitFirstMessage: task.awaitFirstMessage,
+              onMessageHandlers: task.onMessageHandlers,
+              sessionId: message.session_id,
+              abortController: abortController,
+            };
+            this.tasks.push(runningTask);
+            aliveTaskResolve(runningTask);
+            resolved = true;
+          }
+
+          resolveFirstMessage();
+
           await Promise.all(
             task.onMessageHandlers.map(async (onMessageHandler) => {
               await onMessageHandler(message);
@@ -302,6 +333,7 @@ export class ClaudeCodeTaskController {
             });
             resolved = true;
             setFirstMessagePromise();
+            predictSessionsDatabase.deletePredictSession(currentTask.sessionId);
           }
         }
 
@@ -372,7 +404,6 @@ export class ClaudeCodeTaskController {
       awaitFirstMessage: task.awaitFirstMessage,
       onMessageHandlers: task.onMessageHandlers,
       baseSessionId: task.baseSessionId,
-      userMessageId: task.userMessageId,
     });
   }
 
diff --git a/src/server/service/claude-code/ClaudeCodeVersion.ts b/src/server/service/claude-code/ClaudeCodeVersion.ts
index db3b4f3..9193a7e 100644
--- a/src/server/service/claude-code/ClaudeCodeVersion.ts
+++ b/src/server/service/claude-code/ClaudeCodeVersion.ts
@@ -43,6 +43,10 @@ export class ClaudeCodeVersion {
     return this.version.patch;
   }
 
+  public toString() {
+    return `${this.major}.${this.minor}.${this.patch}`;
+  }
+
   public equals(other: ClaudeCodeVersion) {
     return (
       this.version.major === other.version.major &&
diff --git a/src/server/service/claude-code/types.ts b/src/server/service/claude-code/types.ts
index aee0526..c920d14 100644
--- a/src/server/service/claude-code/types.ts
+++ b/src/server/service/claude-code/types.ts
@@ -20,21 +20,18 @@ export type PendingClaudeCodeTask = BaseClaudeCodeTask & {
 export type RunningClaudeCodeTask = BaseClaudeCodeTask & {
   status: "running";
   sessionId: string;
-  userMessageId: string | undefined;
   abortController: AbortController;
 };
 
 export type PausedClaudeCodeTask = BaseClaudeCodeTask & {
   status: "paused";
   sessionId: string;
-  userMessageId: string | undefined;
   abortController: AbortController;
 };
 
 type CompletedClaudeCodeTask = BaseClaudeCodeTask & {
   status: "completed";
   sessionId: string;
-  userMessageId: string | undefined;
   abortController: AbortController;
   resolveFirstMessage: () => void;
 };
@@ -56,7 +53,7 @@ export type AliveClaudeCodeTask = RunningClaudeCodeTask | PausedClaudeCodeTask;
 
 export type SerializableAliveTask = Pick<
   AliveClaudeCodeTask,
-  "id" | "status" | "sessionId" | "userMessageId"
+  "id" | "status" | "sessionId"
 >;
 
 export type PermissionRequest = {
diff --git a/src/server/service/project/id.ts b/src/server/service/project/id.ts
index 5b9f64c..f52d713 100644
--- a/src/server/service/project/id.ts
+++ b/src/server/service/project/id.ts
@@ -1,3 +1,5 @@
+import { dirname } from "node:path";
+
 export const encodeProjectId = (fullPath: string) => {
   return Buffer.from(fullPath).toString("base64url");
 };
@@ -5,3 +7,7 @@ export const encodeProjectId = (fullPath: string) => {
 export const decodeProjectId = (id: string) => {
   return Buffer.from(id, "base64url").toString("utf-8");
 };
+
+export const encodeProjectIdFromSessionFilePath = (sessionFilePath: string) => {
+  return encodeProjectId(dirname(sessionFilePath));
+};
diff --git a/src/server/service/project/projectMetaStorage.ts b/src/server/service/project/projectMetaStorage.ts
index 63d616f..e12814c 100644
--- a/src/server/service/project/projectMetaStorage.ts
+++ b/src/server/service/project/projectMetaStorage.ts
@@ -3,15 +3,15 @@ import { readdir, readFile } from "node:fs/promises";
 import { basename, resolve } from "node:path";
 import { z } from "zod";
 import { FileCacheStorage } from "../../lib/storage/FileCacheStorage";
+import { InMemoryCacheStorage } from "../../lib/storage/InMemoryCacheStorage";
 import { parseJsonl } from "../parseJsonl";
 import type { ProjectMeta } from "../types";
 import { decodeProjectId } from "./id";
-import { InMemoryCacheStorage } from "../../lib/storage/InMemoryCacheStorage";
 
 class ProjectMetaStorage {
   private projectPathCache = FileCacheStorage.load(
     "project-path-cache",
-    z.string().nullable()
+    z.string().nullable(),
   );
   private projectMetaCache = new InMemoryCacheStorage<ProjectMeta>();
 
@@ -31,7 +31,7 @@ class ProjectMetaStorage {
           ({
             fullPath: resolve(claudeProjectPath, d.name),
             stats: statSync(resolve(claudeProjectPath, d.name)),
-          } as const)
+          }) as const,
       )
       .sort((a, b) => {
         return a.stats.mtime.getTime() - b.stats.mtime.getTime();
@@ -70,7 +70,7 @@ class ProjectMetaStorage {
   }
 
   private async extractProjectPathFromJsonl(
-    filePath: string
+    filePath: string,
   ): Promise<string | null> {
     const cached = this.projectPathCache.get(filePath);
     if (cached !== undefined) {
diff --git a/src/server/service/session/PredictSessionsDatabase.ts b/src/server/service/session/PredictSessionsDatabase.ts
new file mode 100644
index 0000000..161b273
--- /dev/null
+++ b/src/server/service/session/PredictSessionsDatabase.ts
@@ -0,0 +1,34 @@
+import { encodeProjectIdFromSessionFilePath } from "../project/id";
+import type { Session, SessionDetail } from "../types";
+
+/**
+ * For interactively experience, handle sessions not already persisted to the filesystem.
+ */
+class PredictSessionsDatabase {
+  private storage = new Map<string, SessionDetail>();
+
+  public getPredictSessions(projectId: string): Session[] {
+    return Array.from(this.storage.values()).filter(
+      ({ jsonlFilePath }) =>
+        encodeProjectIdFromSessionFilePath(jsonlFilePath) === projectId,
+    );
+  }
+
+  public getPredictSession(sessionId: string): SessionDetail {
+    const session = this.storage.get(sessionId);
+    if (!session) {
+      throw new Error("Session not found");
+    }
+    return session;
+  }
+
+  public createPredictSession(session: SessionDetail) {
+    this.storage.set(session.id, session);
+  }
+
+  public deletePredictSession(sessionId: string) {
+    this.storage.delete(sessionId);
+  }
+}
+
+export const predictSessionsDatabase = new PredictSessionsDatabase();
diff --git a/src/server/service/session/SessionRepository.ts b/src/server/service/session/SessionRepository.ts
index 7242025..2fc9c28 100644
--- a/src/server/service/session/SessionRepository.ts
+++ b/src/server/service/session/SessionRepository.ts
@@ -1,9 +1,11 @@
+import { existsSync } from "node:fs";
 import { readdir, readFile } from "node:fs/promises";
 import { resolve } from "node:path";
 import { parseJsonl } from "../parseJsonl";
 import { decodeProjectId } from "../project/id";
 import type { Session, SessionDetail } from "../types";
 import { decodeSessionId, encodeSessionId } from "./id";
+import { predictSessionsDatabase } from "./PredictSessionsDatabase";
 import { sessionMetaStorage } from "./sessionMetaStorage";
 
 const getTime = (date: string | null) => {
@@ -19,6 +21,17 @@ export class SessionRepository {
     session: SessionDetail;
   }> {
     const sessionPath = decodeSessionId(projectId, sessionId);
+    if (!existsSync(sessionPath)) {
+      const predictSession =
+        predictSessionsDatabase.getPredictSession(sessionId);
+      if (predictSession) {
+        return {
+          session: predictSession,
+        };
+      }
+
+      throw new Error("Session not found");
+    }
     const content = await readFile(sessionPath, "utf-8");
 
     const conversations = parseJsonl(content);
@@ -53,9 +66,16 @@ export class SessionRepository {
             ),
           })),
       );
+      const sessionMap = new Map<string, Session>(
+        sessions.map((session) => [session.id, session]),
+      );
+
+      const predictSessions = predictSessionsDatabase
+        .getPredictSessions(projectId)
+        .filter((session) => !sessionMap.has(session.id));
 
       return {
-        sessions: sessions.sort((a, b) => {
+        sessions: [...predictSessions, ...sessions].sort((a, b) => {
           return (
             getTime(b.meta.lastModifiedAt) - getTime(a.meta.lastModifiedAt)
           );
diff --git a/src/server/service/session/sessionMetaStorage.ts b/src/server/service/session/sessionMetaStorage.ts
index b1dc26a..975db76 100644
--- a/src/server/service/session/sessionMetaStorage.ts
+++ b/src/server/service/session/sessionMetaStorage.ts
@@ -1,16 +1,15 @@
 import { statSync } from "node:fs";
 import { readFile } from "node:fs/promises";
 import { FileCacheStorage } from "../../lib/storage/FileCacheStorage";
+import { InMemoryCacheStorage } from "../../lib/storage/InMemoryCacheStorage";
 import {
   type ParsedCommand,
   parseCommandXml,
   parsedCommandSchema,
 } from "../parseCommandXml";
 import { parseJsonl } from "../parseJsonl";
-import { sessionMetaSchema } from "../schema";
 import type { SessionMeta } from "../types";
 import { decodeSessionId } from "./id";
-import { InMemoryCacheStorage } from "../../lib/storage/InMemoryCacheStorage";
 
 const ignoreCommands = [
   "/clear",
@@ -24,13 +23,13 @@ const ignoreCommands = [
 class SessionMetaStorage {
   private firstCommandCache = FileCacheStorage.load(
     "first-command-cache",
-    parsedCommandSchema
+    parsedCommandSchema,
   );
   private sessionMetaCache = new InMemoryCacheStorage<SessionMeta>();
 
   public async getSessionMeta(
     projectId: string,
-    sessionId: string
+    sessionId: string,
   ): Promise<SessionMeta> {
     const cached = this.sessionMetaCache.get(sessionId);
     if (cached !== undefined) {
@@ -60,7 +59,7 @@ class SessionMetaStorage {
 
   private getFirstCommand = (
     jsonlFilePath: string,
-    lines: string[]
+    lines: string[],
   ): ParsedCommand | null => {
     const cached = this.firstCommandCache.get(jsonlFilePath);
     if (cached !== undefined) {
@@ -80,14 +79,14 @@ class SessionMetaStorage {
         conversation === null
           ? null
           : typeof conversation.message.content === "string"
-          ? conversation.message.content
-          : (() => {
-              const firstContent = conversation.message.content.at(0);
-              if (firstContent === undefined) return null;
-              if (typeof firstContent === "string") return firstContent;
-              if (firstContent.type === "text") return firstContent.text;
-              return null;
-            })();
+            ? conversation.message.content
+            : (() => {
+                const firstContent = conversation.message.content.at(0);
+                if (firstContent === undefined) return null;
+                if (typeof firstContent === "string") return firstContent;
+                if (firstContent.type === "text") return firstContent.text;
+                return null;
+              })();
 
       if (firstUserText === null) {
         continue;