For an in-app customer-support chatbot that turns sales calls into CRM actions, use a unified LLM API with automatic failover across OpenAI, Claude, and Gemini, while keeping the CRM write behind an idempotent application boundary. The deciding constraint is provider portability: the chatbot should not change its frontend contract when a model changes or a provider is rate-limited.

That recommendation is narrower than “send every request to the cheapest model.” A summary is disposable; a CRM action is an audit record. The system must retry inference, recognize a repeated action, and explain which model produced the proposed change.

Should a unified LLM API give a multi-provider chatbot automatic fallback?

I treat this as an architecture decision record with four invariants. One client request gets one application request ID. The transcript is immutable for the duration of processing. The model output is a proposal until validation passes.…