Introduction

What is Powsoo?

Voice platforms mishear emails, phone numbers, and addresses. Powsoo fixes that by rendering interactive cards on the caller’s screen at the right moment — tap to confirm, edit if needed, no spelling-back.

Built for Retell and Vapi. Embed in any site with one script tag. Free until you publish a widget.

Quickstart First Powsoo card in under 5 minutes. Connect Retell Add powsoo_show_card to your Retell agent. Card reference Full powsoo_show_card JSON schema and field types. API reference REST endpoints, auth model, and error codes.

How it works

Powsoo has three roles:

Agency — signs up at app.powsoo.com, connects their Retell or Vapi account, configures a widget, copies a snippet. The agency is Powsoo’s only direct customer.

End client — the agency’s customer (a law firm, dentist, e-commerce brand). Pastes the snippet into their site. Never touches Powsoo directly.

End user — the visitor on the end client’s site. Clicks the call button, talks to the voice agent, taps cards. Doesn’t know Powsoo exists.

During a call, audio flows direct between the user’s browser and Retell/Vapi over WebRTC — Powsoo never sees a byte of it. Powsoo is only in the path for tool calls: when the LLM decides to show a card, Retell posts to Powsoo’s webhook, Powsoo pushes the card over Server-Sent Events to the widget, and the user’s tap flows back the same way.

If Powsoo goes down mid-call, audio stays live; only new cards stop appearing.