diff --git a/aicard-web-oauth/.env.development b/aicard-web-oauth/.env.development
index 97c77d4..23e281d 100644
--- a/aicard-web-oauth/.env.development
+++ b/aicard-web-oauth/.env.development
@@ -1,4 +1,9 @@
 # Development environment variables
 VITE_APP_HOST=http://localhost:4173
 VITE_OAUTH_CLIENT_ID=http://localhost:4173/client-metadata.json
-VITE_OAUTH_REDIRECT_URI=http://localhost:4173/oauth/callback
\ No newline at end of file
+VITE_OAUTH_REDIRECT_URI=http://localhost:4173/oauth/callback
+VITE_ADMIN_DID=did:plc:uqzpqmrjnptsxezjx4xuh2mn
+
+# Optional: Override collection names (if not set, auto-generated from host)
+# VITE_COLLECTION_COMMENT=ai.syui.log
+# VITE_COLLECTION_USER=ai.syui.log.user
\ No newline at end of file
diff --git a/aicard-web-oauth/.env.production b/aicard-web-oauth/.env.production
index 15692f4..cdee24b 100644
--- a/aicard-web-oauth/.env.production
+++ b/aicard-web-oauth/.env.production
@@ -1,4 +1,9 @@
 # Production environment variables
 VITE_APP_HOST=https://log.syui.ai
 VITE_OAUTH_CLIENT_ID=https://log.syui.ai/client-metadata.json
-VITE_OAUTH_REDIRECT_URI=https://log.syui.ai/oauth/callback
\ No newline at end of file
+VITE_OAUTH_REDIRECT_URI=https://log.syui.ai/oauth/callback
+VITE_ADMIN_DID=did:plc:uqzpqmrjnptsxezjx4xuh2mn
+
+# Optional: Override collection names (if not set, auto-generated from host)
+# VITE_COLLECTION_COMMENT=ai.syui.log
+# VITE_COLLECTION_USER=ai.syui.log.user
\ No newline at end of file
diff --git a/aicard-web-oauth/src/App.tsx b/aicard-web-oauth/src/App.tsx
index 03232a0..98c6404 100644
--- a/aicard-web-oauth/src/App.tsx
+++ b/aicard-web-oauth/src/App.tsx
@@ -2,6 +2,7 @@ import React, { useState, useEffect } from 'react';
 import { OAuthCallback } from './components/OAuthCallback';
 import { authService, User } from './services/auth';
 import { atprotoOAuthService } from './services/atproto-oauth';
+import { appConfig } from './config/app';
 import './App.css';
 
 function App() {
@@ -54,14 +55,14 @@ function App() {
         ws.onopen = () => {
           console.log('Jetstream connected');
           ws.send(JSON.stringify({
-            wantedCollections: ['ai.syui.log']
+            wantedCollections: [appConfig.collections.comment]
           }));
         };
         
         ws.onmessage = (event) => {
           try {
             const data = JSON.parse(event.data);
-            if (data.collection === 'ai.syui.log' && data.commit?.operation === 'create') {
+            if (data.collection === appConfig.collections.comment && data.commit?.operation === 'create') {
               console.log('New comment detected via Jetstream:', data);
               // Optionally reload comments
               // loadAllComments(window.location.href);
@@ -146,7 +147,7 @@ function App() {
         loadAllComments();
         
         // Load user list records if admin
-        if (userProfile.did === 'did:plc:uqzpqmrjnptsxezjx4xuh2mn') {
+        if (userProfile.did === appConfig.adminDid) {
           loadUserListRecords();
         }
         
@@ -166,7 +167,7 @@ function App() {
         loadAllComments();
         
         // Load user list records if admin
-        if (verifiedUser.did === 'did:plc:uqzpqmrjnptsxezjx4xuh2mn') {
+        if (verifiedUser.did === appConfig.adminDid) {
           loadUserListRecords();
         }
       }
@@ -225,7 +226,7 @@ function App() {
       // Get comments from current user
       const response = await agent.api.com.atproto.repo.listRecords({
         repo: did,
-        collection: 'ai.syui.log',
+        collection: appConfig.collections.comment,
         limit: 100,
       });
 
@@ -268,10 +269,10 @@ function App() {
   // JSONからユーザーリストを取得
   const loadUsersFromRecord = async () => {
     try {
-      // 管理者のユーザーリストを取得 (ai.syui.log.user collection)
-      const adminDid = 'did:plc:uqzpqmrjnptsxezjx4xuh2mn'; // syui.ai
+      // 管理者のユーザーリストを取得
+      const adminDid = appConfig.adminDid;
       console.log('Fetching user list from admin DID:', adminDid);
-      const response = await fetch(`https://bsky.social/xrpc/com.atproto.repo.listRecords?repo=${encodeURIComponent(adminDid)}&collection=ai.syui.log.user&limit=100`);
+      const response = await fetch(`https://bsky.social/xrpc/com.atproto.repo.listRecords?repo=${encodeURIComponent(adminDid)}&collection=${encodeURIComponent(appConfig.collections.user)}&limit=100`);
       
       if (!response.ok) {
         console.warn('Failed to fetch user list from admin, using default users. Status:', response.status);
@@ -331,8 +332,8 @@ function App() {
   const loadUserListRecords = async () => {
     try {
       console.log('Loading user list records...');
-      const adminDid = 'did:plc:uqzpqmrjnptsxezjx4xuh2mn'; // syui.ai
-      const response = await fetch(`https://bsky.social/xrpc/com.atproto.repo.listRecords?repo=${encodeURIComponent(adminDid)}&collection=ai.syui.log.user&limit=100`);
+      const adminDid = appConfig.adminDid;
+      const response = await fetch(`https://bsky.social/xrpc/com.atproto.repo.listRecords?repo=${encodeURIComponent(adminDid)}&collection=${encodeURIComponent(appConfig.collections.user)}&limit=100`);
       
       if (!response.ok) {
         console.warn('Failed to fetch user list records');
@@ -358,8 +359,8 @@ function App() {
 
   const getDefaultUsers = () => {
     const defaultUsers = [
-      // bsky.social - 実際のDIDを使用
-      { did: 'did:plc:uqzpqmrjnptsxezjx4xuh2mn', handle: 'syui.ai', pds: 'https://bsky.social' },
+      // Default admin user
+      { did: appConfig.adminDid, handle: 'syui.ai', pds: 'https://bsky.social' },
     ];
     
     // 現在ログインしているユーザーも追加（重複チェック）
@@ -393,7 +394,7 @@ function App() {
           console.log(`Fetching comments from user: ${user.handle} (${user.did}) at ${user.pds}`);
           
           // Public API使用（認証不要）
-          const response = await fetch(`${user.pds}/xrpc/com.atproto.repo.listRecords?repo=${encodeURIComponent(user.did)}&collection=ai.syui.log&limit=100`);
+          const response = await fetch(`${user.pds}/xrpc/com.atproto.repo.listRecords?repo=${encodeURIComponent(user.did)}&collection=${encodeURIComponent(appConfig.collections.comment)}&limit=100`);
           
           if (!response.ok) {
             console.warn(`Failed to fetch from ${user.handle} (${response.status}): ${response.statusText}`);
@@ -490,12 +491,13 @@ function App() {
         throw new Error('No agent available');
       }
 
-      // Create comment record with ISO datetime rkey
+      // Create comment record with post-specific rkey
       const now = new Date();
-      const rkey = now.toISOString().replace(/[:.]/g, '-'); // Replace : and . with - for valid rkey
+      // Use post rkey if on post page, otherwise use timestamp-based rkey
+      const rkey = appConfig.rkey || now.toISOString().replace(/[:.]/g, '-');
       
       const record = {
-        $type: 'ai.syui.log',
+        $type: appConfig.collections.comment,
         text: commentText,
         url: window.location.href,
         createdAt: now.toISOString(),
@@ -510,7 +512,7 @@ function App() {
       // Post to ATProto with rkey
       const response = await agent.api.com.atproto.repo.putRecord({
         repo: user.did,
-        collection: 'ai.syui.log',
+        collection: appConfig.collections.comment,
         rkey: rkey,
         record: record,
       });
@@ -553,7 +555,7 @@ function App() {
       // Delete the record
       await agent.api.com.atproto.repo.deleteRecord({
         repo: user.did,
-        collection: 'ai.syui.log',
+        collection: appConfig.collections.comment,
         rkey: rkey,
       });
 
@@ -578,7 +580,7 @@ function App() {
 
   // 管理者チェック
   const isAdmin = (user: User | null): boolean => {
-    return user?.did === 'did:plc:uqzpqmrjnptsxezjx4xuh2mn'; // syui.ai
+    return user?.did === appConfig.adminDid;
   };
 
   // ユーザーリスト投稿
@@ -640,7 +642,7 @@ function App() {
       const rkey = now.toISOString().replace(/[:.]/g, '-');
       
       const record = {
-        $type: 'ai.syui.log.user',
+        $type: appConfig.collections.user,
         users: users,
         createdAt: now.toISOString(),
         updatedBy: {
@@ -652,7 +654,7 @@ function App() {
       // Post to ATProto with rkey
       const response = await agent.api.com.atproto.repo.putRecord({
         repo: user.did,
-        collection: 'ai.syui.log.user',
+        collection: appConfig.collections.user,
         rkey: rkey,
         record: record,
       });
@@ -697,7 +699,7 @@ function App() {
       // Delete the record
       await agent.api.com.atproto.repo.deleteRecord({
         repo: user.did,
-        collection: 'ai.syui.log.user',
+        collection: appConfig.collections.user,
         rkey: rkey,
       });
 
@@ -743,6 +745,22 @@ function App() {
     }
   };
 
+  // Rkey-based comment filtering
+  // If on post page (/posts/xxx.html), only show comments with rkey=xxx
+  const shouldShowComment = (record: any): boolean => {
+    // If not on a post page, show all comments
+    if (!appConfig.rkey) {
+      return true;
+    }
+    
+    // Extract rkey from comment URI: at://did:plc:xxx/collection/rkey
+    const uriParts = record.uri.split('/');
+    const commentRkey = uriParts[uriParts.length - 1];
+    
+    // Show comment only if rkey matches current post
+    return commentRkey === appConfig.rkey;
+  };
+
   // OAuth callback is now handled by React Router in main.tsx
   console.log('=== APP.TSX URL CHECK ===');
   console.log('Full URL:', window.location.href);
@@ -896,10 +914,12 @@ function App() {
             <div className="comments-header">
               <h3>Comments</h3>
             </div>
-            {comments.length === 0 ? (
-              <p className="no-comments">No comments yet</p>
+            {comments.filter(shouldShowComment).length === 0 ? (
+              <p className="no-comments">
+                {appConfig.rkey ? `No comments for this post yet` : `No comments yet`}
+              </p>
             ) : (
-              comments.map((record, index) => (
+              comments.filter(shouldShowComment).map((record, index) => (
                 <div key={index} className="comment-item">
                   <div className="comment-header">
                     <img 
@@ -945,8 +965,8 @@ function App() {
             )}
           </div>
 
-          {/* Comment Form - Outside user section, after comments list */}
-          {user && (
+          {/* Comment Form - Only show on post pages */}
+          {user && appConfig.rkey && (
             <div className="comment-form">
               <h3>Post a Comment</h3>
               <textarea
@@ -969,6 +989,14 @@ function App() {
               {error && <p className="error">{error}</p>}
             </div>
           )}
+
+          {/* Show authentication status on non-post pages */}
+          {user && !appConfig.rkey && (
+            <div className="auth-status">
+              <p>✅ Authenticated as @{user.handle}</p>
+              <p><small>Visit a post page to comment</small></p>
+            </div>
+          )}
         </section>
       </main>
 
diff --git a/aicard-web-oauth/src/config/app.ts b/aicard-web-oauth/src/config/app.ts
new file mode 100644
index 0000000..28bac59
--- /dev/null
+++ b/aicard-web-oauth/src/config/app.ts
@@ -0,0 +1,84 @@
+// Application configuration
+export interface AppConfig {
+  adminDid: string;
+  collections: {
+    comment: string;
+    user: string;
+  };
+  host: string;
+  rkey?: string; // Current post rkey if on post page
+}
+
+// Generate collection names from host
+// Format: ${reg}.${name}.${sub}
+// Example: log.syui.ai -> ai.syui.log
+function generateCollectionNames(host: string): { comment: string; user: string } {
+  try {
+    // Remove protocol if present
+    const cleanHost = host.replace(/^https?:\/\//, '');
+    
+    // Split host into parts
+    const parts = cleanHost.split('.');
+    
+    if (parts.length < 2) {
+      throw new Error('Invalid host format');
+    }
+    
+    // Reverse the parts for collection naming
+    // log.syui.ai -> ai.syui.log
+    const reversedParts = parts.reverse();
+    const collectionBase = reversedParts.join('.');
+    
+    return {
+      comment: collectionBase,
+      user: `${collectionBase}.user`
+    };
+  } catch (error) {
+    console.warn('Failed to generate collection names from host:', host, error);
+    // Fallback to default collections
+    return {
+      comment: 'ai.syui.log',
+      user: 'ai.syui.log.user'
+    };
+  }
+}
+
+// Extract rkey from current URL
+// /posts/xxx.html -> xxx
+function extractRkeyFromUrl(): string | undefined {
+  const pathname = window.location.pathname;
+  const match = pathname.match(/\/posts\/([^/]+)\.html$/);
+  return match ? match[1] : undefined;
+}
+
+// Get application configuration from environment variables
+export function getAppConfig(): AppConfig {
+  const host = import.meta.env.VITE_APP_HOST || 'https://log.syui.ai';
+  const adminDid = import.meta.env.VITE_ADMIN_DID || 'did:plc:uqzpqmrjnptsxezjx4xuh2mn';
+  
+  // Priority: Environment variables > Auto-generated from host
+  const autoGeneratedCollections = generateCollectionNames(host);
+  const collections = {
+    comment: import.meta.env.VITE_COLLECTION_COMMENT || autoGeneratedCollections.comment,
+    user: import.meta.env.VITE_COLLECTION_USER || autoGeneratedCollections.user,
+  };
+  
+  const rkey = extractRkeyFromUrl();
+  
+  console.log('App configuration:', {
+    host,
+    adminDid,
+    collections,
+    rkey: rkey || 'none (not on post page)'
+  });
+  
+  return {
+    adminDid,
+    collections,
+    host,
+    rkey
+  };
+}
+
+// Export singleton instance
+export const appConfig = getAppConfig();
\ No newline at end of file