Setting Up Compose HotSwan: zero to sub-second reload on a real device

Compose HotSwan is a JetBrains IDE plugin plus a Gradle compiler plugin that swaps changed Kotlin classes into a running Compose app on a real device or emulator in under one second, preserving navigation, scroll, and remember state. This skill installs both pieces, wires the canonical Gradle DSL with debugOnly = true, and verifies the first save-to-reload round-trip. Sibling skills cover what does and does not hot-reload (../understanding-hot-reload-limits/SKILL.md), state preservation across reloads, and the AI-driven iteration loop.

Versions verified at the time of authoring. Confirm against the current release notes for newer minors.

When to use this skill

• The developer mentions HotSwan, hot reload, instant UI update, "save and see", "no rebuild", live edit, or fast Compose iteration on device.
• The developer has the HotSwan JetBrains Marketplace plugin installed and asks how to apply the Gradle compiler plugin.
• A team is onboarding a new project to HotSwan and wants the canonical libs.versions.toml + root build + app build wiring.
• The developer just installed the IDE plugin and the tool window status is stuck before WATCHING.

When NOT to use this skill

• The question is about JetBrains' own Live Edit or Apply Changes features. HotSwan and those are separate products with different boundaries; do not conflate.
• The question is about Compose Preview rendering inside the IDE. HotSwan targets the running app on a real device or emulator, not preview canvases.
• The question is about which changes hot-reload vs force a rebuild. See ../understanding-hot-reload-limits/SKILL.md.
• The question is about preserving complex state across reloads. See the state-preservation sibling skill (out of scope here).

Prerequisites