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Getting Started with Realtime Messaging

Pick the path that matches your stack and what you're building.

Pick your path​

Using JavaScript or TypeScript?​

Use the @metered-ca/realtime SDK. It handles framing, reconnect, perfect-negotiation WebRTC, and auto-applies the TURN credentials the signalling server injects. Five lines to connect-subscribe-publish, ~30 lines for a working video call.

npm install @metered-ca/realtime

→ JavaScript SDK — Getting Started

Using any other stack?​

Speak the wire protocol directly — Go, Python, Java, Swift, Kotlin, Rust, Unity, anything that can open a WebSocket and sign HS256 JWTs.

→ Introduction → Quickstart — connect, subscribe, and publish in under 30 lines (with Browser and Node tabs)

The SDK and raw-WS clients speak the same protocol byte-for-byte. An SDK client and a raw-WS client can be peers in the same channel.

Just want a copy-paste demo?​

The Single-File HTML Demo runs in one HTML file with no build, no backend, no JWT minting. Demonstrates presence, chat, WebRTC video, and auto-injected TURN in ~200 lines. Save the file, replace the pk_live_ key, open in two browser tabs.

Pick by what you're building​

You're building…Read this first
WebRTC video call with the SDKJS SDK: WebRTC Video Call
WebRTC from a static site (no backend)JS SDK: WebRTC No Backend
WebRTC from a non-JS stackRaw-WS WebRTC Signalling
Chat / classroom / livestream chatJS SDK: Presence & Chat
AI agent communicationJS SDK: AI Agent Communication
IoT telemetryJS SDK: IoT Telemetry
Migrating from simple-peer or PeerJSMigration from simple-peer · from PeerJS

Going to production​

Two pages worth reading before you ship, regardless of which path you took above:

  • Reconnect Best Practices — handling drops, refreshing tokens, surfacing "reconnecting" UI. The single most-skipped doc that bites everyone in production.
  • Limits & Quotas — message size cap, channel cap, per-connection rate limit, plan quotas. Bookmark when sizing a deployment.

If something doesn't work the way you expect, the Troubleshooting guide is symptom-first ("messages aren't arriving", "video stays black", "stuck in reconnecting") rather than code-first.

Reference material​