diff --git a/README.md b/README.md
index 868b762d..1c93bdb8 100644
--- a/README.md
+++ b/README.md
@@ -9,13 +9,11 @@ It includes settings for various tools, such as the shell (Zsh), Git, npm, and V
 - `brew/`: Contains Brewfiles for different operating systems (Linux, macOS) and dependency configurations, including lock files for reproducible package installations. Supports categorized package management and dependency analysis.
 - `credentials/`: Contains templates and scripts for secure credential management using 1Password CLI integration.
 - `dot/`: Directory for dotfiles and configuration files that are typically placed in the home directory.
-- `.devcontainer/`: Contains shared DevContainer configuration files, including Docker setup, versioning documentation, and task completion notification scripts for development environment containerization.
 - `git/`: Contains Git configuration files including gitconfig, gitignore, and modular configuration files in the `gitconfig.d/` subdirectory.
 - `npm/`: Contains npm global package configuration.
 - `script/`: Contains utility scripts for exporting configuration settings (`export.sh`), importing configuration settings (`import.sh`), checking for changes and making commits (`commit_changes.sh`), credential management (`credentials.sh`), Homebrew dependency management (`brew-deps.sh`), and version management (`version.sh`).
 - `supabase/`: Contains Supabase-related configuration and documentation.
 - `vscode/`: Contains Visual Studio Code configuration including extensions list and installation documentation.
-- `.claude/`: Contains Claude AI development guidelines and quality standards, including conversation guidelines and development philosophy documentation.
 
 ## Security
 
@@ -119,46 +117,6 @@ make brew-deps pkg=<package>
 make brew-uses pkg=<package>
 ```
 
-### DevContainer Support
-
-This repository includes shared DevContainer configuration for consistent development environments across projects.
-
-#### Features
-- **Shared configuration**: Reusable DevContainer setup that can be referenced from other repositories
-- **Automated setup**: Automatically applies repository configurations via `script/import.sh` when container starts
-- **Semantic versioning**: Support for versioned DevContainer images using git tags
-- **Task notifications**: Bell notification system for task completion feedback
-
-#### Usage
-Reference the shared DevContainer configuration in your project's `devcontainer.json`:
-
-```jsonc
-{
-  "features": {
-    "../features/common": {}
-  }
-}
-```
-
-#### Versioning
-Create versioned releases of the DevContainer image:
-
-```bash
-# Create a patch version (1.0.0 -> 1.0.1)
-make version-patch
-
-# Create a minor version (1.0.0 -> 1.1.0)  
-make version-minor
-
-# Create a major version (1.0.0 -> 2.0.0)
-make version-major
-
-# Preview next version without creating tag
-make version-dry-run
-```
-
-For detailed DevContainer versioning information, see [.devcontainer/VERSIONING.md](.devcontainer/VERSIONING.md).
-
 ### Automated Releases
 
 This repository uses semantic-release for automated version management and releases based on commit messages. Follow conventional commit format:
@@ -182,7 +140,6 @@ Releases are automatically created when changes are pushed to the main branch.
 - **Supabase**: An open-source Firebase alternative providing backend-as-a-service features.
 - **Semantic Release**: Automated version management and release process based on commit messages.
 - **GitHub Actions**: CI/CD platform integrated with GitHub for automating workflows.
-- **Claude**: AI assistant with development guidelines and quality standards defined in the `.claude/` directory.
 
 ## Disclaimer
 
diff --git a/credentials/README.md b/credentials/README.md
index 5a161708..3e806749 100644
--- a/credentials/README.md
+++ b/credentials/README.md
@@ -7,11 +7,10 @@
 ```
 credentials/
 ├── README.md              # このファイル
+├── setup.md              # 詳細なセットアップガイド
 ├── templates/             # 各種サービスのテンプレート
-│   ├── aws.env.template
-│   ├── github.env.template
-│   ├── npm.env.template
-│   └── general.env.template
+│   ├── aws.env.template   # AWS認証情報用テンプレート
+│   └── simple.env.template # 汎用環境変数テンプレート
 └── .gitignore            # 生成されたファイルを無視
 ```
 
diff --git a/credentials/setup.md b/credentials/setup.md
index 6283e10a..eff4a984 100644
--- a/credentials/setup.md
+++ b/credentials/setup.md
@@ -21,13 +21,6 @@
 
 ### アイテムの作成例
 
-#### GitHub
-- アイテム名: `GitHub`
-- フィールド:
-  - `personal_access_token`: GitHubのPAT
-  - `npm_token`: npm公開用トークン
-  - `rubygems_token`: RubyGems用トークン
-
 #### AWS
 - アイテム名: `AWS`
 - フィールド:
@@ -35,10 +28,10 @@
   - `AWS_SECRET_ACCESS_KEY`: シークレットアクセスキー
   - `AWS_REGION`: デフォルトリージョン
 
-#### OpenAI
-- アイテム名: `OpenAI`
+#### その他のクレデンシャル
+- アイテム名: `Simple`
 - フィールド:
-  - `api_key`: OpenAI APIキー
+  - 簡単な環境変数のテンプレート用
 
 ## 使用方法
 
diff --git a/vscode/README.md b/vscode/README.md
index d57373d3..ee17cb12 100644
--- a/vscode/README.md
+++ b/vscode/README.md
@@ -1,13 +1,63 @@
-## installation
+# Visual Studio Code Configuration
 
-### Unix
+This directory contains Visual Studio Code configuration files and scripts for maintaining a consistent development environment.
 
-```
+## Files
+
+- `extensions.txt`: List of VS Code extensions to be installed
+
+## Installation
+
+### Prerequisites
+
+Ensure Visual Studio Code is installed and the `code` command is available in your PATH.
+
+### Install Extensions
+
+Choose the appropriate method for your operating system:
+
+#### Unix/Linux/macOS
+
+```bash
 cat ./extensions.txt | xargs -L 1 code --install-extension
 ```
 
-### Windows
+#### Windows (PowerShell)
+
+```powershell
+Get-Content ./extensions.txt | ForEach-Object { code --install-extension $_ }
+```
+
+#### Alternative Windows Command
 
+```powershell
+cat ./extensions.txt | % { code --install-extension $_ }
 ```
-cat ./extensions.txt | % { "code --install-extension \$\_" }
+
+## Exporting Current Extensions
+
+To update the `extensions.txt` file with your currently installed extensions:
+
+```bash
+code --list-extensions > extensions.txt
 ```
+
+## Usage in Automation
+
+This extensions list can be used as part of the repository's import script (`../script/import.sh`) to automatically set up a development environment on new machines.
+
+## Troubleshooting
+
+### Extension Installation Fails
+
+- Ensure you're logged into VS Code with your Microsoft/GitHub account
+- Check your internet connection
+- Verify the extension ID is correct in `extensions.txt`
+- Try installing the problematic extension manually first
+
+### `code` Command Not Found
+
+Add VS Code to your PATH:
+- **macOS**: `Command + Shift + P` → "Shell Command: Install 'code' command in PATH"
+- **Windows**: Ensure VS Code installation directory is in your system PATH
+- **Linux**: The `code` command should be available after installation via package manager