Production-ready stack to build WhatsApp AI agents without Meta's API or per-message fees. Includes: docker-compose with 4 services, importable n8n workflow, and LiteLLM as model proxy — switch between Claude, DeepSeek, GPT-4o and Gemini by editing 3 lines. No workflow changes needed. Works with any standard WhatsApp number via QR. Guided install script. Docs in Spanish. Tested in production for ordering agents in local businesses.