While You're Out

How it works

One add-on, three ways in.

While You're Out is an MCP server: the open protocol Alexa+ add-ons are built on. Alexa+ calls its tools and shows its cards on the Echo Show; the parents' and the sitter's phones talk to the same house.

THE DRAWING

Who talks to whom

solid: realdashed: a stand-in, built against the interface the real one would use

Three hosts call the While You're Out MCP server, which talks to the parent's phone, the sitter's phone and simulated stand-ins for Ring, Amazon Pay, a delivery partner, Fire TV and Bee. Alexa+ on Echo Show PLAYED BY THE SIMULATOR (THE ADD-ON CONSOLE SAYS COMING SOON) Today's Alexa AN ALEXA-HOSTED SKILL, AN MCP HOST, TESTED ON AN ECHO SHOW DISPLAY Any MCP host CLAUDE, VS CODE, THE MCP INSPECTOR (ONE LINK ON /CONNECT) While You're Out MCP SERVER · STREAMABLE HTTP · 2025-11-25 23 tools, each with an output schema One MCP Apps card, light and dark Tasks that wait for a parent Elicitation: a form, a payment link The safety rules, in code A house per visitor, OAuth 2.1 PLUS AN AI SECOND LOOK THAT ONLY ADDS CAUTION Parent's phone WEB PUSH · APPROVE · ANSWER Sitter's phone GUEST PASS · WORKS OFFLINE Stand-ins Ring doorbell Amazon Pay Delivery partner and store Fire TV, Bee MCP OVER HTTPS, ALL THREE

ALEXA+ ADD-ON FEATURES

What it uses, and why

Each one carries part of the evening; none is there for its own sake.

FeatureWhere it shows up
MCP Apps cardEvery answer on the Echo Show: the Tonight screen, the emergency guide, the doorbell photo, the goodnight message. One card, sized by the device class, in light and dark.
Tasks"Ask Mom if she can stay up": the question waits for a person, and the answer arrives when she taps it on her lock screen.
Form elicitation"We're heading out" with no name: the Echo Show asks who is babysitting, their language and rate.
URL elicitation"Pay Priya": the payment opens on the parent's own phone, never on the shared screen.
Resources and subscriptionshouse://tonight updates the screen when the TV limit hits or the porch light goes on.
Output schemas, annotations, status textEvery tool says what it returns, whether it changes anything, and what to show while it works.
OAuth 2.1 account linkingA household links once (PKCE, refresh rotation, protected-resource metadata); the demo needs no sign-in.

MEASURED

Fast, sturdy, tested

Full MCP round trips over HTTP, the way a host calls it, on a laptop. Amazon's budget is 500 ms per tool call.

19 msp95 for a tool call, across every tool in 20 scripted eveningsserver/eval/SPEED.md
2,000calls from 50 sessions at once, with no errors239 calls a second
0server errors from 1,500 malformed and hostile requestsfuzz: broken JSON, 5 MB strings, __proto__
440+automated tests on every push: the server, the simulator and the Alexa skillnpm test; CI on every commit

OPEN SOURCE

The simulator is yours too

Alexa+ isn't open to everyone yet, so I built a stand-in for the host: an Echo Show simulator that talks to any MCP add-on the Alexa+ way, with screens for every Echo device, a card audit and a readiness score. It's a project of its own, MIT licensed.

alexa-addon-simulatorThis add-on's code