Embeddr

Dating for AI agents. Find your nearest neighbor.

A workshop app for runtime control with Unleash and an AI coding assistant.

The frontend (Vite, React, Tailwind CSS v4) renders whatever the backend returns. The backend (Fastify) evaluates every feature flag server-side with the Unleash SDK, serves Auto-Rizz opening lines behind the auto-rizz flag, and reports Ick taps to Unleash as an impact metric. Turning a flag off stops real server-side work, and the running app reflects it within seconds without a redeploy.

Run it

Prerequisites: Node.js 22 or later, and an Unleash instance with a Backend token.

1. Copy server/.env.example to server/.env and fill in the Unleash connection values. The frontend needs no configuration for local use; .env.example documents VITE_BACKEND_URL for deployed setups.
2. Run npm install. This also installs the backend dependencies.
3. Run npm run dev.

The frontend runs at http://localhost:5173 and the backend at http://localhost:3001. Use npm run dev:web or npm run dev:api to run either side alone. Without Unleash credentials the backend still boots, every flag evaluates to off, and the app renders the plain Embeddr experience.

Deploy

The repo deploys as one Railway service: railway.json builds the frontend and starts the backend, which serves the built frontend and the API from a single port. Set UNLEASH_API_URL, UNLEASH_CLIENT_TOKEN, and METRICS_INTERVAL in the service variables; Railway provides PORT.

The flags

Every flag is evaluated in the backend with the session id or data-region as Unleash context.

This demo is designed to work with the workshop Unleash instance. If you do not have access to that instance, you can replicate the flags in your own instance or a free trial of Unleash, using the setup column below.

Flag	What it does	Setup
show-QR-code	Floats the join-the-workshop QR code in a corner of the app. Presenter tooling for the live demo.	Release flag, no targeting. A gradual rollout at 100%.
regional-consent-test	The region picked in the header travels as the data-region context field; a strategy constraint matches anything starting with eu- and serves a consent notice on every card in one of two designs, a classic banner or a minimal chip, A/B tested per EU region. Until the box is ticked the opener stays withheld and Match is disabled. Non-EU regions see nothing.	Release flag plus a custom context field named data-region with custom stickiness enabled and no legal values. One strategy: gradual rollout at 100%, a constraint where data-region starts with eu- (case-insensitive), and two 50/50 strategy variants named classic and minimal, each with a string payload matching its name and stickiness set to data-region.
auto-rizz	Serves an opening line on every match card. Ick taps feed the ick_count impact metric that a safeguard watches in production.	Release flag, gradual rollout at 100%, default stickiness. The metric and safeguard are optional extras.
light-mode	Puts a theme toggle in the header. The light or dark choice is the user's own, per session; the flag only decides whether the control exists. Flag off hides the toggle and the app repaints dark.	Release flag, gradual rollout at 100%, no targeting.

With the flags off, or without an Unleash connection at all, the app is plain Embeddr: six cards, no openers, no upsell, no consent info.

The pieces

Path	What it is
src/	The frontend. No Unleash SDK, no flag logic, no token.
server/	The backend. Flag evaluation, openers, the ick impact metric. See server/README.md.
WORKBOOK.md	The attendee workbook. Start here at the workshop.
FALLBACKS.md	Plain commands for every assistant-driven step.
CLAUDE.md, AGENTS.md	Guidance for AI assistants working in this repo.