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skills/working-with-claude-code/references/llm-gateway.md

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+# LLM gateway configuration
+
+> Learn how to configure Claude Code with LLM gateway solutions, including LiteLLM setup, authentication methods, and enterprise features like usage tracking and budget management.
+
+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
+
+## LiteLLM configuration
+
+<Note>
+  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 This guide is provided for informational purposes and may become outdated.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.
+</Note>
+
+### Prerequisites
+
+* Claude Code updated to the latest version
+* LiteLLM Proxy Server deployed and accessible
+* Access to Claude models through your chosen provider
+
+### Basic LiteLLM setup
+
+**Configure Claude Code**:
+
+#### Authentication methods
+
+##### Static API key
+
+Simplest method using a fixed API key:
+
+```bash  theme={null}
+# 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` header.
+
+##### Dynamic API key with helper
+
+For rotating keys or per-user authentication:
+
+1. Create an API key helper script:
+
+```bash  theme={null}
+#!/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"}'
+```
+
+2. Configure Claude Code settings to use the helper:
+
+```json  theme={null}
+{
+  "apiKeyHelper": "~/bin/get-litellm-key.sh"
+}
+```
+
+3. Set token refresh interval:
+
+```bash  theme={null}
+# Refresh every hour (3600000 ms)
+export CLAUDE_CODE_API_KEY_HELPER_TTL_MS=3600000
+```
+
+This value will be sent as `Authorization` and `X-Api-Key` headers. The `apiKeyHelper` has lower precedence than `ANTHROPIC_AUTH_TOKEN` or `ANTHROPIC_API_KEY`.
+
+#### Unified endpoint (recommended)
+
+Using LiteLLM's [Anthropic format endpoint](https://docs.litellm.ai/docs/anthropic_unified):
+
+```bash  theme={null}
+export ANTHROPIC_BASE_URL=https://litellm-server:4000
+```
+
+**Benefits of the unified endpoint over pass-through endpoints:**
+
+* Load balancing
+* Fallbacks
+* Consistent support for cost tracking and end-user tracking
+
+#### Provider-specific pass-through endpoints (alternative)
+
+##### Claude API through LiteLLM
+
+Using [pass-through endpoint](https://docs.litellm.ai/docs/pass_through/anthropic_completion):
+
+```bash  theme={null}
+export ANTHROPIC_BASE_URL=https://litellm-server:4000/anthropic
+```
+
+##### Amazon Bedrock through LiteLLM
+
+Using [pass-through endpoint](https://docs.litellm.ai/docs/pass_through/bedrock):
+
+```bash  theme={null}
+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](https://docs.litellm.ai/docs/pass_through/vertex_ai):
+
+```bash  theme={null}
+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
+```
+
+### Model selection
+
+By default, the models will use those specified in [Model configuration](/en/docs/claude-code/bedrock-vertex-proxies#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](https://docs.litellm.ai/).
+
+## Additional resources
+
+* [LiteLLM documentation](https://docs.litellm.ai/)
+* [Claude Code settings](/en/docs/claude-code/settings)
+* [Enterprise network configuration](/en/docs/claude-code/network-config)
+* [Third-party integrations overview](/en/docs/claude-code/third-party-integrations)