This page covers how to configure Claude Code with LLM gateway solutions, including LiteLLM setup, authentication methods, and enterprise features like usage tracking and budget management.

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Overview

LLM gateways provide a centralized proxy layer between Claude Code and model providers, offering:

  • Centralized authentication - Single point for API key management
  • Usage tracking - Monitor usage across teams and projects
  • Cost controls - Implement budgets and rate limits
  • Audit logging - Track all model interactions for compliance
  • Model routing - Switch between providers without code changes

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LiteLLM configuration

LiteLLM is a third-party proxy service. Anthropic doesn’t endorse, maintain, or audit LiteLLM’s security or functionality. This guide is provided for informational purposes and may become outdated. Use at your own discretion.

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Prerequisites

  • Claude Code updated to the latest version
  • LiteLLM Proxy Server deployed and accessible
  • Access to Claude models through your chosen provider

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Basic LiteLLM setup

Configure Claude Code:

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Authentication methods

Static API key

Simplest method using a fixed API key:

# Set in environment
export ANTHROPIC_AUTH_TOKEN=sk-litellm-static-key

# Or in Claude Code settings
{
  "env": {
    "ANTHROPIC_AUTH_TOKEN": "sk-litellm-static-key"
  }
}

This value will be sent as the Authorization and Proxy-Authorization headers, although Authorization may be overwritten (see Vertex “Client-specified credentials” below).

Dynamic API key with helper

For rotating keys or per-user authentication:

  1. Create an API key helper script:
#!/bin/bash
# ~/bin/get-litellm-key.sh

# Example: Fetch key from vault
vault kv get -field=api_key secret/litellm/claude-code

# Example: Generate JWT token
jwt encode \
  --secret="${JWT_SECRET}" \
  --exp="+1h" \
  '{"user":"'${USER}'","team":"engineering"}'
  1. Configure Claude Code settings to use the helper:
{
  "apiKeyHelper": "~/bin/get-litellm-key.sh"
}
  1. Set token refresh interval:
# Refresh every hour (3600000 ms)
export CLAUDE_CODE_API_KEY_HELPER_TTL_MS=3600000

This value will be sent as Authorization, Proxy-Authorization, and X-Api-Key headers, although Authorization may be overwritten (see Google Vertex AI through LiteLLM). The apiKeyHelper has lower precedence than ANTHROPIC_AUTH_TOKEN or ANTHROPIC_API_KEY.

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Provider-specific configurations

Anthropic API through LiteLLM

Using pass-through endpoint:

export ANTHROPIC_BASE_URL=https://litellm-server:4000/anthropic
Amazon Bedrock through LiteLLM

Using pass-through endpoint:

export ANTHROPIC_BEDROCK_BASE_URL=https://litellm-server:4000/bedrock
export CLAUDE_CODE_SKIP_BEDROCK_AUTH=1
export CLAUDE_CODE_USE_BEDROCK=1
Google Vertex AI through LiteLLM

Using pass-through endpoint:

Recommended: Proxy-specified credentials

export ANTHROPIC_VERTEX_BASE_URL=https://litellm-server:4000/vertex_ai/v1
export ANTHROPIC_VERTEX_PROJECT_ID=your-gcp-project-id
export CLAUDE_CODE_SKIP_VERTEX_AUTH=1
export CLAUDE_CODE_USE_VERTEX=1
export CLOUD_ML_REGION=us-east5

Alternative: Client-specified credentials

If you prefer to use local GCP credentials:

  1. Authenticate with GCP locally:
gcloud auth application-default login
  1. Set Claude Code environment:
export ANTHROPIC_VERTEX_BASE_URL=https://litellm-server:4000/vertex_ai/v1
export ANTHROPIC_VERTEX_PROJECT_ID=your-gcp-project-id
export CLAUDE_CODE_USE_VERTEX=1
export CLOUD_ML_REGION=us-east5
  1. Update LiteLLM header configuration:

Ensure your LiteLLM config has general_settings.litellm_key_header_name set to Proxy-Authorization, since the pass-through GCP token will be located on the Authorization header.

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Unified endpoint

Using LiteLLM’s Anthropic format endpoint:

export ANTHROPIC_BASE_URL=https://litellm-server:4000

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Model selection

By default, the models will use those specified in Model configuration.

If you have configured custom model names in LiteLLM, set the aforementioned environment variables to those custom names.

For more detailed information, refer to the LiteLLM documentation.

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Additional resources