Glossary

Short definitions of the words these docs use in a Flitz-specific sense. For the mechanism that connects them, read How it works.

The two halves

Host

Your app with the Flitz loader embedded, built from a pinned Flitz SDK in release mode and installed like any build of your app. It carries the engine, the compiled Dart runtime, and every native plugin — everything a bundle may use.

Bundle (.flitz)

Your app's Dart code, its Dart packages, and the Flutter framework compiled to bytecode, plus assets and a manifest, packaged as a .flitz archive. A bundle is a complete app build, never a patch or diff. The host downloads it and runs it — on Android in a separate process next to your app, on iOS in place of your app's UI until the app is relaunched.

Loader

The component inside the host that fetches a bundle, checks it against the host, and runs it — signing the user in first when you turn on sign-in. It ships as a plugin for your Android and iOS projects.

Panel

The loader's own screens in a host with sign-in, where a signed-in teammate browses your organization's apps, their tracks, and their builds, and runs one without a link. An Enterprise feature, like sign-in. See Sign-in and the panel.

Flitz SDK

A Flutter SDK built for Flitz, plus the tools that build bundles. Host and bundle must be built with the same SDK pin. Release tags look like <flutter-version>+flz.<N>.

Flitz iteration

The <N> in an SDK release tag. It increases with every Flitz release, across Flutter versions. Each loader-plugin version needs a minimum iteration; the host build and the loader both check it, and flitz plugins configure picks the plugin version your pin meets.

Portal

The Flitz web app at app.flitz.dev where your organization browses its publishes by app and track, decides who can download each app's builds, manages members and the API key, and handles billing. See Portal.

Organizing publishes

App

A named group of your organization's publishes, identified by a key — by default your pubspec.yaml name:. Each app has its tracks, its download access, and a state: live, archived, or deleted. Pro includes one app; more are part of Flitz Enterprise. See Apps and tracks.

Track

One line of builds within an app, usually a Git branch. Its track link always opens the newest complete build on it. Publishes made without a branch land on the app's Unassigned track.

Download access

Who can download an app's builds: Anyone with the link (the default), or Members only — only a host with sign-in, for a signed-in member of your organization, an Enterprise feature. The Owner and Admins set it per app in the portal. See Download access.

How a bundle fits a host

Envelope

What a host was built with: its Flitz SDK and its packages with native code. A bundle can use anything inside the envelope and nothing outside it — adding a native dependency means a new host build.

Manifest

The small file inside a bundle stating what it needs from a host: the Flitz SDK it was built with and the packages with native code it depends on.

Compatibility check

The loader's validation, before anything runs, that a bundle fits its host: the same SDK, every native package covered, and a loader plugin that supports the host's SDK. A mismatch is refused with an error naming it. Fitting is not the same as being safe — see first-party bundles.

Platform fingerprint

A hash of the Flitz SDK's platform libraries, recorded in every bundle and in every host. The loader error Platform dill hash mismatch means the two were built with different SDKs.

Dynamic interface

The platform APIs — dart:* and dart:ui — that bundle code may call, extend, or override. A statically typed use outside it fails flitz publish on your machine. On SDKs with Dart 3.13 or newer, a dynamic call into the platform outside it fails when it runs; older SDKs do not check dynamic calls.

Trust

First-party bundles

The supported model: bundles built by your own team. A bundle runs with the full privileges of the host — in a host with sign-in, that includes the signed-in teammate's Flitz session — and the loader does not check where a bundle came from, so the compatibility check guarantees fit, not safety — untrusted third-party bundles are not supported.