Revert CLAUDE_API_KEY to ANTHROPIC_API_KEY throughout the repository

Reverted all instances of CLAUDE_API_KEY back to ANTHROPIC_API_KEY to maintain
compatibility with existing infrastructure and GitHub secrets. This affects:
- Environment variable examples (.env.example files)
- Python scripts and notebooks
- Documentation and README files
- Evaluation scripts and test files

Other naming changes (Claude API, Claude Console, Claude Docs, Claude Cookbook) remain intact.

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

Author: zealoushacker

.claude/commands/notebook-review.md

@@ -17,7 +17,7 @@ https://docs.claude.com/en/docs/about-claude/models/overview.md
 - Python code follows PEP 8 conventions
 - Proper error handling
 - Clear variable names and documentation
-- No hardcoded API keys (use os.getenv("CLAUDE_API_KEY"))
+- No hardcoded API keys (use os.getenv("ANTHROPIC_API_KEY"))
 
 ## Notebook Structure
 - Clear introduction explaining what the notebook demonstrates and why it's useful

.env.example

@@ -2,7 +2,7 @@
 # Copy this file to .env and add your API key
 # Get your API key at: https://platform.claude.com/settings/keys
 
-CLAUDE_API_KEY=sk-ant-api03-...
+ANTHROPIC_API_KEY=sk-ant-api03-...
 
 # Optional: Default model for testing (recommended for cost savings)
 CLAUDE_MODEL=claude-3-5-haiku-latest

CONTRIBUTING.md

@@ -113,7 +113,7 @@ If a hook fails, fix the issues and try committing again.
 1. **Use environment variables for API keys**:
    ```python
    import os
-   api_key = os.environ.get("CLAUDE_API_KEY")
+   api_key = os.environ.get("ANTHROPIC_API_KEY")
    ```
 
 2. **Use current Claude models**:

claude_code_sdk/.env.example

@@ -6,4 +6,4 @@ GITHUB_TOKEN="your-github-personal-access-token-here"
 # Claude API Key
 # Required for using Claude SDK
 # Get your key at: https://platform.claude.com/settings/keys
-CLAUDE_API_KEY="sk-ant-api03-your-api-key-here"
+ANTHROPIC_API_KEY="sk-ant-api03-your-api-key-here"

claude_code_sdk/README.md

@@ -26,7 +26,7 @@ A tutorial series demonstrating how to build sophisticated general-purpose agent
 1. Visit [platform.claude.com](https://platform.claude.com/dashboard)
 2. Sign up or log in to your account
 3. Click on "Get API keys"
-4. Copy the key and paste it into your `.env` file as ```CLAUDE_API_KEY=```
+4. Copy the key and paste it into your `.env` file as ```ANTHROPIC_API_KEY=```
 
 #### 5. GitHub Token for Notebook 02
 If you plan to work through the Observability Agent notebook:

extended_thinking/extended_thinking.ipynb

@@ -59,7 +59,7 @@
     "import os\n",
     "\n",
     "# Set your API key as an environment variable or directly\n",
-    "# os.environ[\"CLAUDE_API_KEY\"] = \"your-api-key-here\"\n",
+    "# os.environ[\"ANTHROPIC_API_KEY\"] = \"your-api-key-here\"\n",
     "\n",
     "# Initialize the client\n",
     "client = anthropic.Anthropic()\n",

extended_thinking/extended_thinking_with_tool_use.ipynb

@@ -63,7 +63,7 @@
     "THINKING_BUDGET_TOKENS = 2000\n",
     "\n",
     "# Set your API key as an environment variable or directly\n",
-    "# os.environ[\"CLAUDE_API_KEY\"] = \"your_api_key_here\"\n",
+    "# os.environ[\"ANTHROPIC_API_KEY\"] = \"your_api_key_here\"\n",
     "\n",
     "# Initialize the client\n",
     "client = anthropic.Anthropic()\n",

misc/illustrated_responses.ipynb

@@ -39,9 +39,9 @@
    "outputs": [],
    "source": [
     "STABILITY_API_KEY = \"\" # Stability API key goes here\n",
-    "CLAUDE_API_KEY = \"\" # Claude API key goes here\n",
+    "ANTHROPIC_API_KEY = \"\" # Claude API key goes here\n",
     "MODEL_NAME = \"claude-3-opus-20240229\"\n",
-    "CLIENT = anthropic.Anthropic(api_key=CLAUDE_API_KEY)"
+    "CLIENT = anthropic.Anthropic(api_key=ANTHROPIC_API_KEY)"
    ]
   },
   {

misc/mc_qa.ipynb

@@ -47,7 +47,7 @@
     "import anthropic, os, re, requests, trio, pandas as pd\n",
     "import numpy as np\n",
     "from bs4 import BeautifulSoup\n",
-    "API_KEY = os.environ['CLAUDE_API_KEY']\n",
+    "API_KEY = os.environ['ANTHROPIC_API_KEY']\n",
     "CLIENT = anthropic.Anthropic(api_key=API_KEY)"
    ]
   },

misc/metaprompt.ipynb

@@ -48,9 +48,9 @@
    "outputs": [],
    "source": [
     "import anthropic, re\n",
-    "CLAUDE_API_KEY = \"\" # Put your API key here!\n",
+    "ANTHROPIC_API_KEY = \"\" # Put your API key here!\n",
     "MODEL_NAME = \"claude-3-5-sonnet-20241022\"\n",
-    "CLIENT = anthropic.Anthropic(api_key=CLAUDE_API_KEY)"
+    "CLIENT = anthropic.Anthropic(api_key=ANTHROPIC_API_KEY)"
    ]
   },
   {