Interactive Python shell

pyRevit ships an interactive IronPython console that runs on the engine the current session is loaded with. Statements execute against the live model, with syntax highlighting and Ctrl+Space autocompletion.

It lives at pyRevit tab → pyRevit panel → Python Shell.

The console is built on AvalonEdit and lives in dev/pyRevitLabs.PyRevit.Shell.

Opening modes

Shift+click the button to pick how it opens. The choice persists in the button's script config, so the next plain click uses it.

Mode	Window	Editor pane	Needs an open project
Modeless (default)	Floating, non-blocking	no	no
Modeless Editor	Floating, non-blocking	yes	no
Modal	Blocks Revit until closed	no	no
Modal Editor	Blocks Revit until closed	yes	no
Docked	Revit dockable pane	no	yes
Docked Editor	Revit dockable pane	yes	yes

The editor variants add a code panel beside the prompt, for composing something longer than a single statement before running it.

Docked modes need an open project because Revit only hosts dockable panes when a document is open. Picking one with no project loaded raises a dialog pointing you at the modeless modes; the button itself is context: zero-doc, so it stays enabled either way.

Which engine it runs on

The shell creates a new IronPython host that uses the same deployment/runtime family as the engine pyRevit is already loaded with. It locates the loaded pyRevitLoader assembly and loads pyRevitLabs.PyRevit.Shell.dll from beside it, which preserves the active engine fork. It also copies the launching engine's sys.path into the console, so imports resolve the same way they do in a normal script.

That means it is IronPython only. The shell assembly is deployed to IPY2712PR and IPY342, not to the CPython engines. For the non-docked modes, if pyRevit is running on a CPython engine, the button reports that the shell is not installed for the active engine. For Docked and Docked Editor modes, if the pane is unavailable, the button reports that the Python Shell pane is not registered for this session.

Theming

The console follows Revit's UI theme rather than always rendering dark — the prompt, the editor surface, the completion popups, and the dockable pane's own background all switch together. See Theming and dark mode.

Keeping Revit responsive

Statements in modeless and docked shells are marshalled through a Revit ExternalEvent. Revit stays interactive while a modeless or docked shell is open, and the statement runs in a valid API context, so model modifications behave the same as they would from a button.

Startup cost

Registering the dockable pane does not load the shell:

• The pane defaults to hidden, and is re-hidden on the first Idling tick after startup. Revit persists dockable pane visibility across sessions, so without this a pane you opened once would reappear in every later session.
• pyRevitLabs.PyRevit.Shell.dll loads during session startup so the dockable pane can be registered. The console itself is built later, on an Idling handler once the pane is shown.

A shell you never open still incurs assembly loading and pane registration, but not console construction.

Troubleshooting

"Python Shell is not installed for the active engine" — the shell DLL is missing next to the loaded engine. Expected on CPython engines; on an IronPython engine it means the deployment is incomplete, so rebuild or reinstall.

"The docked Python Shell pane is not registered for this session" — the pane is registered at startup by pyRevitCore.extension/startup.py. Reload pyRevit, or switch to a modeless mode.

The pane is empty — a build failure renders its traceback inside the pane rather than leaving a blank surface, so read the pane first, then the log.