Stream Sync Engage

Now with AI-powered Routing

[session/init] Product pitch loaded

Stream Sync Engage is a delightful and easy to use platform to send targeted instant messages to your app users. You can easily send notifications, surveys, product tours, voice mail, and slideshows. No code required; Just install the snippet, design your message and schedule the send.

SSE
Stream Sync Engage now

A live notification engine built for modern apps that want to go beyond static push. Deliver intelligent, timely, context-aware interactions with seamless offline recovery and AI-powered routing.

[demo/video pending]

What is Stream Sync Engage?

A no-code platform for sending targeted in-app engagements to your users. Install the snippet, design the message, schedule the send.

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STREAM

Continuous, real-time delivery. Engagements flow to the right user the moment events unfold, not in a nightly batch.

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SYNC

Context, state, and devices stay aligned. Smart routing reads what the user is doing and reconciles offline cleanly when they return.

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ENGAGE

Built for two-way interaction. Surveys, voicemail, guided tours, and slideshows. Formats that earn a response, not just a glance.

Features

Seven engagement formats, one engine. Pick the shape that fits the moment, from a quick survey to a multi-step guided tour.

Surveys In-app questionnaires for product feedback
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Learn more about Surveys
Feedback Capture sentiment without leaving the app
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Learn more about Feedback
Voicemail Async voice messages from users in context
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Learn more about Voicemail
Guided tours Onboard and educate without a dev cycle
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Learn more about Guided tours
Slideshows Inline announcements and walkthroughs
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Learn more about Slideshows
A/B tests Validate engagement variations without instrumentation
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Learn more about A/B tests
Questionnaires Structured intake for any user flow
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Learn more about Questionnaires
Read the docs

For product managers

Plan, target, and ship engagements that land in the right moment, without a release cycle behind every change. Iterate copy, audiences, and timing in the browser, then push the version that wins.

Audience targeting Segments, traits, behavioral cohorts
Define who sees each engagement by behavior, traits, lifecycle stage, or custom cohort. Layer rules together to reach exactly the slice of users you want, without engineering work or a code push.
Visual composer Build tours, surveys, and slideshows without code
Design every format in the browser. Drag pieces into place, edit copy inline, swap layouts, preview live, then publish. No tickets, no waiting on the next release.
Experimentation A/B variants, holdouts, gradual rollouts
Ship multiple variants and let traffic decide. Hold a control group, ramp from one percent to one hundred, or pause instantly if a result drifts. Every engagement is a test you can learn from.
Engagement analytics Opens, conversions, cohort retention
Track opens, drop-off, conversion, and downstream retention by cohort. Compare variants, segments, or time windows side by side and tie engagement decisions to the metrics you actually report on.
Explore use cases

For developers

One snippet for the simple path, SDKs and APIs for the deep one. Built on protocols your stack already speaks, with the hooks your team needs to own delivery end to end.

Documentation Drop-in snippet, SDKs, REST API
Quickstarts for every stack. One snippet for the simple path, native SDKs for deeper integration, and a REST API for everything else. Reference docs, runnable examples, and changelogs in one place.
Dev tools CLI, local emulator, log inspector
Run engagements locally before they touch users. Inspect delivery, routing, and recovery logs in real time. The CLI scripts everything you would otherwise click, so workflows fit cleanly into CI.
Knowledge base Patterns, recipes, recovery guides
Battle-tested patterns for common flows, recipes for the tricky cases (offline recovery, ordering, idempotency), and step-by-step guides for when something needs to be rolled back safely.
Partner program Build integrations and earn revenue
Build integrations against the public API and list them in the partner directory. Approved partners earn revenue share on every account that adopts their integration.
Start building

For early adopters

Stream protocols, AI-native primitives, and raw hooks that drop cleanly into whatever experimental stack you are already running. Beta features ship behind flags so you can opt in early and feedback while the design is still moving.

Stream-native protocols SSE, WebSocket, no polling
Built on Server-Sent Events with a WebSocket fallback. No polling loops, no nightly batches, no glue jobs. Engagements arrive as the underlying events fire, on the same primitives modern infrastructure already speaks.
AI-native primitives Agent triggers, MCP, model routing
Treat engagements as first-class agent tools. Wire MCP-compatible triggers, route by model output, and let agents send, schedule, or pause flows the way they would call any other API.
Composable by default Webhooks, event firehose, BYO client
Webhooks both directions, a raw event firehose, and an OpenAPI spec for the whole surface. Slot Stream Sync Engage into Inngest, Temporal, n8n, or whatever orchestrator you already trust, or skip the UI and drive everything from your own code.
Experimental track Beta features and protocols, opt in early
New formats, transport upgrades, and AI-side experiments land behind feature flags first. Flip them on per environment, run them next to the stable surface, and ship feedback while it still changes the design.
Get into the sandbox

FAQ

What is Stream Sync Engage?
Stream Sync Engage (SSE) is a real-time notification and control engine built for developers who need instant, reliable delivery. It provides a live event pipeline that can push both user-facing notifications and functional app commands without requiring new builds or restarts. SSE supports haptic and auditory cues, segment targeting, feature toggles, and graceful offline recovery, all through a TypeScript SDK and a secure MCP (Message Control Plane) server. Whether you are building engagement systems, operational dashboards, or context-aware mobile apps, SSE gives you a low-latency, developer-friendly framework for streaming intelligence directly into your stack.
Who is it for?
Product, growth, and lifecycle teams who want to ship rich in-app interactions without a release cycle. Developers integrate it once. The rest of the team operates it.
Do I need to write code to set up?
You install a snippet once. After that, designing and sending engagements happens entirely inside the Stream Sync Engage app.
How is this different from push notifications?
Push notifications interrupt users outside your product. Stream Sync Engage runs in-app, in the moment the user is already there. The format range is wider too: surveys, voicemail, slideshows, guided tours, not just text alerts.
How do I get started?
Read the quickstart in the docs, install the snippet, and design your first engagement. Most teams have something live in under an hour.
What does it cost?
See the pricing page for current tiers.
Is my data secure?
Stream Sync Engage handles routing and delivery without storing your raw event payloads beyond what is required to deliver the engagement. A full security overview lives in the docs.

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