import clr
clr.AddReference('ProtoGeometry')
clr.AddReference("RevitServices")
clr.AddReference("RevitAPI")
clr.AddReference("RevitNodes")
import Revit
clr.ImportExtensions(Revit.GeometryConversion)

from Autodesk.DesignScript.Geometry import *

from Autodesk.Revit.DB import *
import RevitServices
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager

pt1 = XYZ(0,0,0);
ra = 10;
sta = 0;
en = 360;
XA = XYZ(1,0,0);
YA = XYZ(0,1,0);
# Get the document
doc = DocumentManager.Instance.CurrentDBDocument
view = doc.ActiveView
# "Start" the transaction
TransactionManager.Instance.EnsureInTransaction(doc)

arca = Arc.Create(pt1,ra,sta,en,XA,YA);

arcline = doc.Create.NewDetailCurve(view,arca);

# "End" the transaction
TransactionManager.Instance.TransactionTaskDone()

OUT = arca