Voice agent
A serverless voice agent on AWS that answers your business phone, replies from your own knowledge in real time, and politely passes the rest to a human. Seven posts on the same system — one diagram at a time — with an engineering reference at the end.
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01
A voice agent on AWS for the price of a phone plan
The whole system on one page — a listener, a brain, a speaker, and the under-one-second loop they share.
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02
How a call connects
Three ways a call can go: voicemail after hours, AI session in business hours, or direct human transfer for VIP numbers.
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03
How the listener hears
Streaming transcription, partial guesses refined live, locked the moment the caller pauses.
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04
How the brain decides what to say
Four tools, one pick per turn: answer, book, transfer, end. The AI is allowed to be confident or to defer — never to invent.
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05
How the speaker stays natural
The latency budget for a one-second-or-less reply. Where each millisecond goes, and what happens when the budget blows.
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06
What the voice agent costs
Phone-bill territory at SMB volume. The phone number is the floor; everything else scales with how often it rings.
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07
Engineering reference: the voice agent architecture
Same system, drawn purely for engineers. Service names, resource identifiers, region, Bedrock model IDs.