adding support for claude code routing (#575)

* fixed for claude code routing. first commit

* removing redundant enum tags for cache_control

* making sure that claude code can run via the archgw cli

* fixing broken config

* adding a README.md and updated the cli to use more of our defined patterns for params

* fixed config.yaml

* minor fixes to make sure PR is clean. Ready to ship

* adding claude-sonnet-4-5 to the config

* fixes based on PR

* fixed alias for README

* fixed 400 error handling tests, now that we write temperature to 1.0 for GPT-5

---------

Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-257.local>
Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-288.local>

demos/use_cases/claude_code/README.md

@@ -0,0 +1,133 @@
+# Claude Code Routing with (Preference-aligned) Intelligence
+
+## Why This Matters
+
+**Claude Code is powerful, but what if you could access the best of ALL AI models through one familiar interface?**
+
+Instead of being locked into a set of LLMs from one provier, imagine:
+- Using **DeepSeek's coding expertise** for complex algorithms
+- Leveraging **GPT-5's reasoning** for architecture decisions
+- Tapping **Claude's analysis** for code reviews
+- Accessing **Grok's speed** for quick iterations
+
+**All through the same Claude Code interface you already love.**
+
+## The Solution: Intelligent Multi-LLM Routing
+
+Arch Gateway transforms Claude Code into a **universal AI development interface** that:
+
+### 🌐 **Connects to Any LLM Provider**
+- **OpenAI**: GPT-4.1, GPT-5, etc.
+- **Anthropic**: Claude 3.5 Sonnet, Claude 3 Haiku, Claude 4.5
+- **DeepSeek**: DeepSeek-V3, DeepSeek-Coder-V2
+- **Grok**: Grok-2, Grok-2-mini
+- **Others**: Gemini, Llama, Mistral, local models via Ollama
+
+### 🧠 **Routes Intelligently Based on Task**
+Our research-backed routing system automatically selects the optimal model by analyzing:
+- **Task complexity** (simple refactoring vs. architectural design)
+- **Content type** (code generation vs. debugging vs. documentation)
+
+
+## Quick Start
+
+### Prerequisites
+- Claude Code installed: `npm install -g @anthropic-ai/claude-code`
+- Docker running on your system
+- Create a python virtual environment in your current working directory
+
+### 1. Get the Configuration File
+Download the demo configuration file using one of these methods:
+
+**Option A: Direct download**
+```bash
+curl -O https://raw.githubusercontent.com/katanemo/arch/main/demos/use_cases/claude_code/config.yaml
+```
+
+**Option B: Clone the repository**
+```bash
+git clone https://github.com/katanemo/arch.git
+cd arch/demos/use_cases/claude_code
+
+```
+
+### 2. Set Up Your API Keys
+Set up your environment variables with your actual API keys:
+```bash
+export OPENAI_API_KEY="your-openai-api-key"
+export ANTHROPIC_API_KEY="your-anthropic-api-key"
+export AZURE_API_KEY="your-azure-api-key"  # Optional
+```
+
+Alternatively, create a `.env` file in your working directory:
+```bash
+echo "OPENAI_API_KEY=your-openai-api-key" > .env
+echo "ANTHROPIC_API_KEY=your-anthropic-api-key" >> .env
+```
+
+### 3. Install and Start Arch Gateway
+```bash
+pip install archgw
+archgw up
+```
+
+### 4. Launch Claude Code with Multi-LLM Support
+```bash
+archgw cli-agent claude
+```
+
+That's it! Claude Code now has access to multiple LLM providers with intelligent routing.
+
+## What You'll Experience
+
+### Screenshot Placeholder
+![Claude Code with Multi-LLM Routing](screenshot-placeholder.png)
+*Claude Code interface enhanced with intelligent model routing and multi-provider access*
+
+### Real-Time Model Selection
+When you interact with Claude Code, you'll get:
+- **Automatic model selection** based on your query type
+- **Transparent routing decisions** showing which model was chosen and why
+- **Seamless failover** if a model becomes unavailable
+
+## Configuration
+
+The setup uses the included `config.yaml` file which defines:
+
+### Multi-Provider Access
+```yaml
+llm_providers:
+  - model: openai/gpt-4.1-2025-04-14
+    access_key: $OPENAI_API_KEY
+    routing_preferences:
+    - name: code generation
+        description: generating new code snippets and functions
+  - model: anthropic/claude-3-5-sonnet-20241022
+    access_key: $ANTHROPIC_API_KEY
+    routing_preferences:
+        name: code understanding
+        description: explaining and analyzing existing code
+```
+## Advanced Usage
+
+### Custom Model Selection
+```bash
+# Force a specific model for this session
+archgw cli-agent claude --settings='{"ANTHROPIC_SMALL_FAST_MODEL": "deepseek-coder-v2"}'
+
+# Enable detailed routing information
+archgw cli-agent claude --settings='{"statusLine": {"type": "command", "command": "ccr statusline"}}'
+```
+
+### Environment Variables
+The system automatically configures:
+```bash
+ANTHROPIC_BASE_URL=http://127.0.0.1:12000  # Routes through Arch Gateway
+ANTHROPIC_SMALL_FAST_MODEL=arch.claude.code.small.fast    # Uses intelligent alias
+```
+
+## Real Developer Workflows
+
+This intelligent routing is powered by our research in preference-aligned LLMM routing:
+- **Research Paper**: [Preference-Aligned LLM Router](https://arxiv.org/abs/2506.16655)
+- **Technical Docs**: [docs.archgw.com](https://docs.archgw.com)