TL;DR: The best LLM API for fintech text summarization in Node.js is a chat completion that turns an already-transcribed sales call into a small, validated set of CRM actions. Keep transcription outside this decision. Select a model by the quality-latency trade-off, count tokens before long inputs, and keep the provider boundary at the text handoff.

The practical choice is a capable small model for routine calls, with a stronger model reserved for ambiguous commitments, compliance language, or several speakers talking over one another. A single HTTP surface can make that boundary easier to operate, but it does not make model quality interchangeable. That distinction matters more than a price table.

For this handoff, Infrai is worth testing early when the same service also needs other backend capabilities.…