Guide to Using Claude Code via ZenMux

Claude Code is Anthropic’s official coding agent. Through its integration with ZenMux, you can access a broader selection of models beyond the official Claude API. This guide provides two usage options: the Direct Configuration approach and the Proxy approach.

Comparison of the Two Approaches

We provide two different approaches. Choose based on your specific needs:

Feature	Method 1: Direct Configuration	Method 2: Proxy Approach
Configuration	Simple; environment variables	Moderate; requires a proxy
Model Support	Claude family only for now	All models on ZenMux
Startup	Start Claude Code directly	Start the proxy first
Resource Usage	Lightweight	Additional proxy process
Use Case	Quick migration for Claude	Users needing multi-model

Recommendation

• If you primarily use the Claude family, we recommend Method 1 for simpler setup.
• If you need to switch among multiple models, we recommend Method 2 for broader functionality.

Method 1: Direct Configuration (Claude Models)

Install Claude Code

npm/pnpm

# Install with pnpm (recommended)
pnpm install -g @anthropic-ai/claude-code

# Or install with npm
npm install -g @anthropic-ai/claude-code

Configure Environment Variables

Set the following environment variables to use ZenMux with the Anthropic API format:

# Set ZenMux API base URL (Anthropic format)
export ANTHROPIC_BASE_URL=https://zenmux.ai/api/anthropic   

# Set your ZenMux API Key
export ANTHROPIC_AUTH_TOKEN=sk-ai-v1-xxx  

# Specify the model to use (Claude family)
export ANTHROPIC_MODEL=anthropic/claude-sonnet-4  
export ANTHROPIC_SMALL_FAST_MODEL=anthropic/claude-sonnet-4  

Important Configuration

Make sure to replace sk-ai-v1-xxx with your actual ZenMux API Key. You can obtain your API Key from the ZenMux Console.

Start Directly

After configuring the environment variables, navigate to your project directory and start Claude Code:

# Go to the project directory
cd my-project

# Start Claude Code directly
claude

Convenience

You can add the environment variables to your shell configuration file to avoid setting them manually each time:

# Add to your .bashrc or .zshrc
export ANTHROPIC_BASE_URL=https://zenmux.ai/api 
export ANTHROPIC_AUTH_TOKEN=sk-ai-v1-xxx
export ANTHROPIC_MODEL=anthropic/claude-sonnet-4
export ANTHROPIC_SMALL_FAST_MODEL=anthropic/claude-sonnet-4

Models Currently Natively Supported on ZenMux via the Anthropic Protocol

#	Model slug
1	anthropic/claude-sonnet-4
2	anthropic/claude-opus-4.1
3	deepseek/deepseek-chat
4	qwen/qwen3-coder-plus
5	moonshotai/kimi-k2-0905
6	z-ai/glm-4.5
7	z-ai/glm-4.5-air

---

Method 2: Proxy Approach (All Models Supported)

If you need to use all models available on the ZenMux platform (including GPT, Gemini, etc.), use the proxy approach.

Installation Steps

1. Install Claude Code

First, install Anthropic’s official Claude Code tool:

npm/pnpm

# Install with pnpm (recommended)
pnpm install -g @anthropic-ai/claude-code

# Or install with npm
npm install -g @anthropic-ai/claude-code

Documentation

For detailed features and usage of Claude Code, see the official Claude Code documentation

2. Install Claude Code Proxy

Claude Code Proxy is an open-source project that proxies Claude Code requests to the ZenMux platform.

Open Source Credit

Thanks to the project author fuergaosi233.

Using UV (recommended)

# Clone the proxy repository
git clone https://github.com/fuergaosi233/claude-code-proxy.git
cd claude-code-proxy

# Install dependencies with UV
uv sync

Using pip

# Clone the proxy repository
git clone https://github.com/fuergaosi233/claude-code-proxy.git
cd claude-code-proxy

# Install dependencies with pip
pip install -r requirements.txt

3. Configure Environment Variables

Edit the .env file in the claude-code-proxy project to configure your ZenMux API details and preferred models:

# Copy .env.example to .env; skip if .env already exists
cp .env.example .env

# ZenMux API Key
OPENAI_API_KEY="sk-ai-v1-xxx"

# ZenMux API base URL
OPENAI_BASE_URL="https://zenmux.ai/api/v1"

# Model mapping configuration (optional)
BIG_MODEL="anthropic/claude-opus-4.1"
MIDDLE_MODEL="anthropic/claude-sonnet-4"
SMALL_MODEL="openai/gpt-4o-mini"

Important Configuration

Make sure to replace sk-ai-v1-xxx with your actual ZenMux API Key. You can obtain your API Key from the ZenMux Console

Start the Services

1. Start Claude Code Proxy

Start with UV

# Go to the project directory
cd claude-code-proxy

# Load environment variables and start the service
source .env
uv run claude-code-proxy

Start with Python

# Go to the project directory
cd claude-code-proxy

# Load environment variables and start the service
source .env
python -m claude-code-proxy

After a successful startup, you will see output similar to the following:

2. Start the Claude Code Client

In a new terminal window, start the Claude Code client with:

ANTHROPIC_BASE_URL=http://localhost:8082 ANTHROPIC_API_KEY="any-value" claude

Convenience

You can add the above command to your shell configuration file as a convenient alias:

# Add to your .bashrc or .zshrc
alias claude-zenmux='ANTHROPIC_BASE_URL=http://localhost:8082 ANTHROPIC_API_KEY="any-value" claude'

Supported Models

Method 2, via the proxy approach, supports all models on the ZenMux platform, including:

• Claude family: anthropic/claude-opus-4.1, anthropic/claude-sonnet-4, anthropic/claude-haiku-4
• GPT family: openai/gpt-5, openai/gpt-4o, openai/gpt-4o-mini, openai/gpt-5-mini, openai/gpt-5-nana
• Gemini family: google/gemini-pro, google/gemini-flash
• Other models: See more in the ZenMux model list

Usage Experience

Once configured, you can use all ZenMux models within Claude Code:

Troubleshooting

Common Issues

Connection Failure

Problem: Claude Code cannot connect to the proxy service.

Solution:

• Ensure Claude Code Proxy is running
• Check whether port 8082 is in use
• Verify whether your firewall is blocking local connections

API Key Error

Problem: The API Key is invalid or unauthorized.

Solution:

• Check whether the ZenMux API Key in the .env file is correct
• Confirm the API Key is active and has sufficient balance
• Verify the API Key format starts with sk-ai-v1-

Viewing Logs

If you encounter issues, check the Claude Code Proxy logs for troubleshooting. The proxy service displays detailed request and response information to help you quickly locate the problem.

Advanced Configuration

Custom Model Mapping

You can adjust the model mapping in the .env file based on your needs:

Cost-optimized

# Model choices focused on cost efficiency
BIG_MODEL="anthropic/claude-sonnet-4"
MIDDLE_MODEL="openai/gpt-5-mini"
SMALL_MODEL="openai/gpt-5-nana"

Performance-first

# Model choices focused on performance
BIG_MODEL="anthropic/claude-opus-4.1"
MIDDLE_MODEL="anthropic/claude-sonnet-4"
SMALL_MODEL="openai/gpt-5"

Balanced

# Balanced performance and cost
BIG_MODEL="anthropic/claude-sonnet-4"
MIDDLE_MODEL="anthropic/claude-sonnet-4"
SMALL_MODEL="openai/gpt-5-mini"

This allows you to achieve the best balance of performance and cost across different usage scenarios.

More Models

See the ZenMux model list for all available models and details.