Introduction
LiteLLM unifies APIs from over 100 language models behind a single OpenAI-compatible interface. In 2026, teams use this proxy to centralize authentication, enforce routing policies, and collect detailed metrics. This tutorial covers an expert installation with multi-provider configuration, conditional routing, and a production-ready deployment.
Prerequisites
- Docker 24+ and Docker Compose
- Advanced knowledge of Python and LLMs
- OpenAI, Anthropic, and Groq API accounts
- Access to a Kubernetes cluster or VPS with 8 GB RAM
Project Initialization
mkdir litellm-production && cd litellm-production
pip install litellm[proxy]==1.35.0
cat > config.yaml << 'EOF'
model_list:
- model_name: gpt-4o
litellm_params:
model: openai/gpt-4o
api_key: ${OPENAI_API_KEY}
EOFCreate the project directory and install the exact LiteLLM version. The config.yaml file defines the first model using environment variables to secure API keys.
Multi-Provider Configuration
model_list:
- model_name: gpt-4o
litellm_params:
model: openai/gpt-4o
api_key: ${OPENAI_API_KEY}
- model_name: claude-3-5-sonnet
litellm_params:
model: anthropic/claude-3-5-sonnet-20241022
api_key: ${ANTHROPIC_API_KEY}
- model_name: llama-3.3-70b
litellm_params:
model: groq/llama-3.3-70b-versatile
api_key: ${GROQ_API_KEY}
rpm: 100
litellm_settings:
drop_params: true
request_timeout: 120Complete configuration for three providers with rate limits. The drop_params setting prevents errors from incompatible parameters across models.
Advanced Routing Configuration
router_settings:
routing_strategy: latency-based
fallbacks:
- gpt-4o: [claude-3-5-sonnet, llama-3.3-70b]
model_group_alias:
fast-model: llama-3.3-70b
smart-model: gpt-4o
allowed_fails: 3
cooldown_time: 30Enable latency-based routing with automatic fallback. Aliases simplify client calls while ensuring resilience.
Starting the Proxy Server
export OPENAI_API_KEY=sk-...
export ANTHROPIC_API_KEY=sk-ant-...
export GROQ_API_KEY=gsk-...
litellm --config config.yaml --port 4000 --num_workers 8 --telemetry falseLaunch the proxy in high-performance mode with 8 workers. Telemetry is disabled for privacy in production.
Advanced Logging Configuration
litellm_settings:
success_callback: ["langfuse", "prometheus"]
failure_callback: ["langfuse"]
langfuse_public_key: ${LANGFUSE_PUBLIC_KEY}
langfuse_secret_key: ${LANGFUSE_SECRET_KEY}
prometheus_port: 9090Integrate Langfuse for tracing and Prometheus for metrics. Every LLM call is tracked with tokens, latency, and cost.
Best Practices
- Always use environment variables for API keys
- Configure fallbacks for every critical model
- Enable user rate limiting using X-Forwarded-For headers
- Monitor cost per model with Prometheus + Grafana
- Version the config.yaml file in Git
Common Errors to Avoid
- Forgetting to set environment variables before launching
- Using identical model names without aliases
- Ignoring timeouts on slower models like Claude
- Failing to enable logging callbacks in production
Going Further
Explore our complete training on production LLM architectures: https://learni-group.com/formations. You will learn horizontal scaling of LiteLLM and integration with LangChain.