A session is the whole canvas: nodes, connections and gains, groups, the device and its settings, and plugin settings.

DoHow
Save⋮ → Save, name it. Every tier
Load⋮ → Load (Pro)
Clear⋮ → New - click twice to confirm

At startup#

Free starts with an empty canvas every time. Pro chooses in Preferences → General → When Routling starts:

ChoiceOpens
Resume where I left offEverything as it was when Routling closed, tray panel changes included
Load a sessionA saved session you pick
Start emptyAn empty canvas

If the last run ended with a driver crash, Routling starts empty and names the driver.

When something is missing#

MissingWhat happens
The session's ASIO deviceYou pick another ASIO device or the built-in clock (which leaves out the ASIO channel nodes)
A secondary device or appKept as a placeholder; reconnects when it returns
A network stream's senderThe Network In waits and connects when the sender is back
A pluginRemoved from its chain

Files#

All in %APPDATA%\Routling: sessions\ (named sessions), session.json (what Resume reopens), preferences.json, window-state.json.