Design Guide: Glossary

Add-on

An integration that connects a product or service into Alexa+, enabling customers to access it through voice and touch within the Alexa+ interface on supported devices.

Account linking

The process of connecting a customer's third-party service account to their Alexa account, enabling authenticated and personalized experiences.

Base design canvas

The 768×480px reference resolution for authoring Alexa+ UI. UI authored at this size is scaled up to each device class using a root scale factor.

Block viewport

A viewport type that scales and scrolls horizontally. Recommended for native Alexa+ designs built for screen-based Echo devices.

Card viewport

A viewport type that scales and scrolls vertically. Primarily intended for web-based UI.

Category integration

A path that connects an add-on to an existing Alexa+ category.

CSP (Content Security Policy)

Declared in _meta.ui.csp. Specifies which network destinations a widget can reach — connectDomains for fetch/XHR/WebSocket, resourceDomains for images and media. Anything not declared is blocked.

Data-only response

An MCP tool response that contains data but no UI payload. Alexa renders data-only responses through its native hydration layer.

Design token

A named variable in the Alexa design system representing a specific visual value such as a typography size, spacing measurement, or corner radius. Tokens ensure consistency across components and surfaces.

Fullscreen mode

An expanded display mode that provides more screen real estate for complex interactions such as games, maps, and information-dense content.

Inline mode

The default display mode for MCP add-ons. Content renders directly within the conversation flow. Used for confirmations, summaries, and most add-on responses.

Invocation name

The word or phrase customers say to activate a specific add-on. For example, "Alexa, open [invocation name]." Also the name that appears in the store listing.

MCP add-on

An add-on built using the Model Context Protocol that deploys custom UI directly into the Alexa+ interface. The developer builds and ships the experience; Alexa renders it.

Root scale

A single scale factor applied at the root element of a widget to adapt it to a specific device class. For Echo Show 8/15 (1280×800), the root scale is 1.667.

UI payload

The visual component returned by an MCP add-on in its tool response. When a UI payload is provided, Alexa renders it directly in the interface.

Voice-only mode

The display mode used automatically on Alexa devices without a screen. All content must be intelligible without any visual support.

VoiceView

Amazon's screen reader for Alexa devices. When VoiceView is enabled, on-screen content is navigated by touch and read aloud. Add-ons must function correctly with VoiceView enabled.

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Last updated: Jul 21, 2026