diff --git a/.claude/settings.json b/.claude/settings.json
index 69677966..2960bd1a 100644
--- a/.claude/settings.json
+++ b/.claude/settings.json
@@ -23,7 +23,6 @@
       "WebFetch(domain:docs.speechmatics.com)",
       "WebFetch(domain:docs.sentry.io)",
       "mcp__ide__getDiagnostics",
-      "mcp__o3__o3-search",
       "Bash(ls:*)",
       "Bash(cat:*)",
       "Bash(head:*)",
diff --git a/.codex/config.toml b/.codex/config.toml
index 16ac9589..bbd2472b 100644
--- a/.codex/config.toml
+++ b/.codex/config.toml
@@ -25,11 +25,6 @@ args = ["-y", "next-devtools-mcp@latest"]
 command = "npx"
 args = ["@playwright/mcp@latest"]
 
-[mcp_servers.o3]
-command = "npx"
-args = ["o3-search-mcp"]
-env = { OPENAI_API_KEY = "${OPENAI_API_KEY}", SEARCH_CONTEXT_SIZE = "medium", REASONING_EFFORT = "medium" }
-
 [mcp_servers.supabase]
 url = "https://mcp.supabase.com/mcp"
 
diff --git a/.devcontainer/claude-settings.json b/.devcontainer/claude-settings.json
index 2c2b13f3..54c02718 100644
--- a/.devcontainer/claude-settings.json
+++ b/.devcontainer/claude-settings.json
@@ -229,8 +229,6 @@
       "mcp__supabase__get_logs",
       "mcp__supabase__list_tables",
       "mcp__supabase__list_edge_functions",
-      "mcp__linear__get_issue",
-      "mcp__o3__o3-search",
       "Bash(psql:*)",
       "Bash(PGPASSWORD=postgres psql:*)",
       "Bash(docker:*)",
@@ -330,7 +328,6 @@
       "Bash(claude marketplace update:*)",
       "Bash(claude plugin install:*)",
       "Bash(claude plugin uninstall:*)",
-      "Bash(npx o3-search-mcp:*)",
       "Read(//.codex/**)",
       "Read(//.claude/plugins/**)",
       "Read(//home/vscode/**)",
diff --git a/.devcontainer/claude-settings.local.json b/.devcontainer/claude-settings.local.json
index 9bc184f4..2a98a273 100644
--- a/.devcontainer/claude-settings.local.json
+++ b/.devcontainer/claude-settings.local.json
@@ -244,7 +244,6 @@
       "Bash(supervisorctl stop:*)",
       "Bash(supervisord:*)",
       "Bash(act:*)",
-      "Bash(npx o3-search-mcp:*)",
       "Bash(cargo install:*)",
       "Bash(/home/vscode/.local/bin/mise trust)",
       "Bash(/home/vscode/.local/bin/mise ls)",
@@ -321,7 +320,7 @@
     "defaultMode": "acceptEdits"
   },
   "enableAllProjectMcpServers": true,
-  "enabledMcpjsonServers": ["playwright", "o3"],
+  "enabledMcpjsonServers": ["playwright"],
   "hooks": {
     "PreToolUse": [
       {
diff --git a/.mcp.json b/.mcp.json
index 60195888..b285f74b 100644
--- a/.mcp.json
+++ b/.mcp.json
@@ -6,23 +6,6 @@
       "args": ["@playwright/mcp@latest"],
       "env": {}
     },
-    "o3": {
-      "type": "stdio",
-      "command": "npx",
-      "args": ["o3-search-mcp"],
-      "env": {
-        "OPENAI_API_KEY": "${OPENAI_API_KEY}",
-        "SEARCH_CONTEXT_SIZE": "medium",
-        "REASONING_EFFORT": "medium"
-      }
-    },
-    "linear": {
-      "type": "http",
-      "url": "https://mcp.linear.app/mcp",
-      "headers": {
-        "Authorization": "Bearer ${LINEAR_API_KEY}"
-      }
-    },
     "github": {
       "type": "http",
       "url": "https://api.githubcopilot.com/mcp/"
diff --git a/AGENTS.md b/AGENTS.md
index 3f47f738..3c5922c8 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -60,36 +60,3 @@ The repository includes comprehensive automated workflows for continuous integra
 - **Quality Gates**: Enforced code standards and automated feedback
 - **Container Registry**: Published DevContainer images at `ghcr.io/keito4/config-base`
 - **Semantic Releases**: Automatic GitHub releases with generated release notes
-
-## Technical Assistance with o3 MCP
-
-When encountering technical challenges, unresolved errors, or implementation roadblocks during development, consult o3 MCP in English for advanced problem-solving assistance. o3 MCP specializes in:
-
-- Complex debugging scenarios
-- Architecture design decisions
-- Performance optimization strategies
-- Advanced algorithm implementation
-- Error resolution and root cause analysis
-
-### Usage Guidelines
-
-1. **When to consult o3 MCP**:
-   - Stuck on implementation details
-   - Encountering persistent errors
-   - Need architectural guidance
-   - Performance bottlenecks
-   - Complex algorithm design
-
-2. **How to engage**:
-   - Formulate your question in English
-   - Provide relevant context and error messages
-   - Include code snippets if applicable
-   - Specify what solutions you've already attempted
-
-3. **Example consultation format**:
-   ```
-   I'm encountering [specific issue] while implementing [feature/functionality].
-   Error message: [exact error]
-   What I've tried: [attempted solutions]
-   Context: [relevant code or architecture details]
-   ```
diff --git a/README.md b/README.md
index ee3543a4..63438096 100644
--- a/README.md
+++ b/README.md
@@ -645,39 +645,6 @@ The `CLAUDE.md` file defines organization-wide development standards in Japanese
 - **Git Workflow**: Conventional commits, branch naming conventions, and pull request requirements
 - **AI Prompt Design Guidelines**: Structured approach for requirements definition and implementation
 
-#### Technical Assistance with o3 MCP
-
-When encountering technical challenges, unresolved errors, or implementation roadblocks during development, consult o3 MCP (integrated via Model Context Protocol) for advanced problem-solving assistance. o3 MCP specializes in:
-
-- Complex debugging scenarios and error resolution
-- Architecture design decisions and pattern recommendations
-- Performance optimization strategies
-- Advanced algorithm implementation
-- Real-time web search for latest documentation and solutions
-- Root cause analysis for persistent issues
-
-**Usage Guidelines:**
-
-1. **When to consult o3 MCP**:
-   - Stuck on complex implementation details
-   - Encountering persistent errors or bugs
-   - Need architectural guidance or design review
-   - Performance bottlenecks requiring optimization
-   - Complex algorithm design and implementation
-
-2. **Integration with Claude Code**:
-   - o3 MCP is accessible through Claude Code's MCP integration
-   - Formulate questions in English for optimal results
-   - Include relevant context, error messages, and code snippets
-   - Specify what solutions you've already attempted
-
-3. **Example consultation**:
-   ```
-   @claude Use o3 MCP to help debug this async/await deadlock issue
-   @claude Consult o3 MCP for optimizing this database query performance
-   @claude Ask o3 MCP about best practices for implementing this design pattern
-   ```
-
 #### Slack Notifications Integration
 
 The repository includes automated Slack notifications for development workflow events:
diff --git a/docs/mcp-servers-guide.md b/docs/mcp-servers-guide.md
index f1b21e4f..17498092 100644
--- a/docs/mcp-servers-guide.md
+++ b/docs/mcp-servers-guide.md
@@ -20,37 +20,6 @@ MCPサーバーは `.mcp.json` ファイルで設定します。このファイ
 
 ## 利用可能なMCPサーバー
 
-### Linear
-
-Linearプロジェクト管理ツールとの統合。Issue/Project操作が可能になります。
-
-**設定:**
-
-```json
-{
-  "mcpServers": {
-    "linear": {
-      "type": "http",
-      "url": "https://mcp.linear.app/mcp",
-      "headers": {
-        "Authorization": "Bearer ${LINEAR_API_KEY}"
-      }
-    }
-  }
-}
-```
-
-**必要な環境変数:**
-
-- `LINEAR_API_KEY`: Linear APIキー（Settings > API > Personal API keysで取得）
-
-**利用可能な操作:**
-
-- Issueの作成・更新・検索
-- Projectの管理
-- Cycleの操作
-- チームメンバーの確認
-
 ### Playwright
 
 ブラウザ自動化とE2Eテスト支援。
@@ -77,38 +46,6 @@ Linearプロジェクト管理ツールとの統合。Issue/Project操作が可
 - スクリーンショット取得
 - アクセシビリティスナップショット
 
-### o3-search (OpenAI)
-
-高度なWeb検索とリサーチ機能。
-
-**設定:**
-
-```json
-{
-  "mcpServers": {
-    "o3": {
-      "type": "stdio",
-      "command": "npx",
-      "args": ["o3-search-mcp"],
-      "env": {
-        "OPENAI_API_KEY": "${OPENAI_API_KEY}",
-        "SEARCH_CONTEXT_SIZE": "medium",
-        "REASONING_EFFORT": "medium"
-      }
-    }
-  }
-}
-```
-
-**必要な環境変数:**
-
-- `OPENAI_API_KEY`: OpenAI APIキー
-
-**オプション設定:**
-
-- `SEARCH_CONTEXT_SIZE`: `small`, `medium`, `large`
-- `REASONING_EFFORT`: `low`, `medium`, `high`
-
 ### GitHub
 
 GitHub操作の統合。
@@ -196,23 +133,6 @@ Supabaseデータベースとの統合。
       "args": ["@playwright/mcp@latest"],
       "env": {}
     },
-    "o3": {
-      "type": "stdio",
-      "command": "npx",
-      "args": ["o3-search-mcp"],
-      "env": {
-        "OPENAI_API_KEY": "${OPENAI_API_KEY}",
-        "SEARCH_CONTEXT_SIZE": "medium",
-        "REASONING_EFFORT": "medium"
-      }
-    },
-    "linear": {
-      "type": "http",
-      "url": "https://mcp.linear.app/mcp",
-      "headers": {
-        "Authorization": "Bearer ${LINEAR_API_KEY}"
-      }
-    },
     "github": {
       "type": "http",
       "url": "https://api.githubcopilot.com/mcp/"
@@ -235,19 +155,19 @@ Supabaseデータベースとの統合。
 1. **シェルで直接設定**
 
    ```bash
-   export LINEAR_API_KEY="lin_api_xxx"
+   export SUPABASE_URL="https://xxx.supabase.co"
    ```
 
 2. **1Passwordなどのシークレット管理ツール**
 
    ```bash
-   export LINEAR_API_KEY=$(op read "op://vault/linear/api-key")
+   export SUPABASE_KEY=$(op read "op://vault/supabase/api-key")
    ```
 
 3. **direnvを使用**
    ```bash
    # .envrc
-   export LINEAR_API_KEY="lin_api_xxx"
+   export SUPABASE_URL="https://xxx.supabase.co"
    ```
 
 ## トラブルシューティング