Claude Code Integration

Claude Code is locked to Anthropic's API by default. With LLM Gateway, you can point it at any model—GPT-5, Gemini, Llama, or 180+ others—while keeping the same Anthropic API format Claude Code expects.

Three environment variables. No code changes. Full cost tracking in your dashboard.

Setup

export ANTHROPIC_BASE_URL=https://api.llmgateway.io
export ANTHROPIC_AUTH_TOKEN=llmgtwy_your_api_key_here
# optional: specify a model, otherwise it uses the default Claude model
export ANTHROPIC_MODEL=gpt-5  # or any model from our catalog

claude

Why This Works

LLM Gateway's /v1/messages endpoint speaks Anthropic's API format natively. We handle the translation to each provider behind the scenes. This means:

• Use any model — GPT-5, Gemini, Llama, or Claude itself
• Keep your workflow — Claude Code doesn't know the difference
• Track costs — Every request appears in your LLM Gateway dashboard
• Automatic caching — Repeated requests hit cache, saving money

Choosing Models

You can use any model from the models page.

Use OpenAI's Latest Models

# Use the latest GPT model
export ANTHROPIC_MODEL=gpt-5

# Use a cost-effective alternative
export ANTHROPIC_MODEL=gpt-5-mini

Use Google's Gemini

export ANTHROPIC_MODEL=gemini-2.5-pro

Use Anthropic's Claude Models

export ANTHROPIC_MODEL=anthropic/claude-3-5-sonnet-20241022

Environment Variables

ANTHROPIC_MODEL

Specifies the main model to use for primary requests.

export ANTHROPIC_MODEL=gpt-5

Complete Configuration Example

export ANTHROPIC_BASE_URL=https://api.llmgateway.io
export ANTHROPIC_AUTH_TOKEN=llmgtwy_your_api_key_here
export ANTHROPIC_MODEL=gpt-5
export ANTHROPIC_SMALL_FAST_MODEL=gpt-5-nano

Making Manual API Requests

If you want to test the endpoint directly, you can make manual requests:

curl -X POST "https://api.llmgateway.io/v1/messages" \
  -H "Authorization: Bearer $LLM_GATEWAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5",
    "messages": [
      {"role": "user", "content": "Hello, how are you?"}
    ],
    "max_tokens": 100
  }'

Response Format

The endpoint returns responses in Anthropic's message format:

{
	"id": "msg_abc123",
	"type": "message",
	"role": "assistant",
	"model": "gpt-5",
	"content": [
		{
			"type": "text",
			"text": "Hello! I'm doing well, thank you for asking. How can I help you today?"
		}
	],
	"stop_reason": "end_turn",
	"stop_sequence": null,
	"usage": {
		"input_tokens": 13,
		"output_tokens": 20
	}
}

What You Get

• Any model in Claude Code — GPT-5 for heavy lifting, GPT-4o Mini for routine tasks
• Cost visibility — See exactly what each coding session costs
• One bill — Stop managing separate accounts for OpenAI, Anthropic, Google
• Response caching — Repeated requests (like linting the same file) hit cache
• Discounts — Check discounted models for savings up to 90%