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Introducing moqtap

By moqtap team

Introducing moqtap

MoQT (Media over QUIC Transport) is one of the most exciting protocols being developed at the IETF. It promises low-latency media delivery over QUIC — but building on it today means navigating a tooling vacuum.

There’s no Wireshark dissector for MoQT. Browser DevTools don’t understand MoQT semantics. Relay implementations vary wildly in feature support. Debugging means reading raw byte logs and adding println! to your Rust code.

moqtap changes that.

What is moqtap?

moqtap is a protocol debugger and toolkit for MoQT that gives you direct visibility into sessions — whether you’re building a publisher, subscriber, relay, or CDN node. It ships as a CLI, a desktop app, and a browser extension, so you can debug MoQT wherever you work.

CLI

The moqtap CLI is the fastest way to probe and debug MoQT relays from your terminal:

  • moqtap peek — connect to a relay and discover namespaces, tracks, and live data. Auto-detects transport (QUIC or WebTransport) and draft version.
  • moqtap intercept — a transparent proxy that sits between your MoQT client and relay, parsing every frame inline without modifying traffic. Supports recording sessions to .moqtrace files.
  • moqtap trace — replay and inspect recorded .moqtrace files offline.

Every command supports JSON output (--json / --format json) for scripting, hex dumps for raw byte inspection, and filtering by message type or session.

Install it however you prefer:

Terminal window
curl -sSf https://moqtap.com/install.sh | sh     # macOS/Linux
irm https://moqtap.com/install.ps1 | iex         # Windows PowerShell
brew install moqtap/tap/moqtap                   # Homebrew
npm install -g moqtap                            # npm
winget install moqtap.moqtap                     # winget
cargo install moqtap-cli                         # Cargo

Desktop app

moqtap Desktop is a graphical application for macOS, Windows, and Linux. Connect to any relay, browse namespaces and tracks, inspect every control message and data object, view QUIC transport stats in real time, and export or import .moqtrace session traces — all without touching a terminal.

Download it from the download page or from GitHub Releases.

Browser extension

The WebTransport Inspector extension brings MoQT debugging into your browser’s DevTools. It intercepts all WebTransport connections on a page — including inside iframes — auto-detects MoQT traffic, and gives you:

  • Full control message decoding with field-level detail and chunk reassembly
  • Dedicated Tracks tab with per-track timing, namespace grouping, and direction filters
  • Stream and datagram inspector with virtual-scrolled lists, text filtering, and transfer stats
  • ISO BMFF media detection — classifies payloads as CMAF, LOC, or fMP4 with box-level detail
  • Auto-detection for CBOR and MessagePack payloads alongside JSON
  • Hex viewer with inline object boundary banners and per-object navigation
  • Recording controls — pause capture or clear stream data on demand
  • Live bitrate display and .moqtrace export/import

Available for Chrome and Firefox.

Protocol coverage

moqtap targets MoQT draft-14 as the primary version, with multi-draft support spanning drafts 07–17. It handles both QUIC and WebTransport, parses 31+ control message types, reassembles data stream objects, and detects payload formats including JSON, fMP4, LOC, and MSF.

Open source core

The protocol core is MIT-licensed and split across Rust and JavaScript:

Rust crates:

JavaScript packages:

  • @moqtap/codec — multi-draft MoQT codec (zero dependencies)
  • @moqtap/trace — .moqtrace reader/writer for the browser and Node.js

Use them in your own projects, contribute back, or just read the code.

Get started

Head to the docs to get started, check out the pricing page for Pro and Enterprise options, or follow our progress on GitHub.