Socket Types

A socket is the point where 2 nodes can be linked. Therefor sockets are the main interface between a node and the user. You might think having many different socket types is unnecessary but it has very important advantages.

  • It can help finding which sockets make sense to connect; Although this is not always the case because some sockets change there type automatically when they are linked.
  • The clearer a socket is defined the better the performance of a node because it doesn’t have to check the input type which adds a lot of overhead. That is also the main reason why Python is slower than many compiled languages.

Currently there are 36 different socket types, but this may change over time. To see which sockets you have installed go to the addon directory and take a look into the sockets folder. All files except and represent one socket.

Many sockets come in pairs. E.g. there is an Object and an Object List socket. List sockets are by default just an empty python list (not a tuple!). To get the bl_idname of a list socket take the base id name and insert List before Socket. Sockets that have a corresponding list data type are often called base sockets.

All Data Types

Data Type bl_idname Has List Function or the data it carries
BMesh an_BMeshSocket No BMesh
Boolean an_BooleanSocket No True or False
Color an_ColorSocket No List with four floats: [red, green, blue, alpha]
Edge Indices an_EdgeIndicesSocket Yes Tuple containing two integers
Float an_FloatSocket Yes Normal python float value
Generic an_GenericSocket No Can contain anything; Take care when converting to another type
Integer an_IntegerSocket Yes Normal python integer value
Interpolation an_InterpolationSocket No Tuple: (interpolation function, settings; is often None)
Matrix an_MatrixSocket Yes Matrix
Mesh Data an_MeshDataSocket No Class that contains vertex locations and edge/polygon indices
Node Control an_NodeControlSocket No Contains no data; the function depends on the node where it is used
Object an_ObjectSocket Yes Object (can be a mesh, lamp, camera, ...) or None
Object Group an_ObjectGroupSocket No Object Group or None
Particle an_ParticleSocket Yes Particle object or None
Particle System an_ParticleSystemSocket Yes Particle System object or None
Polygon an_PolygonSocket Yes Contains vertices, area, center, normal and material index
Polygon Indices an_PolygonIndicesSocket Yes Tuple containing at least 3 integers
Sequence an_SequenceSocket No Sequence
Spline an_SplineSocket Yes Either a poly or bezier spline object
String an_StringSocket Yes Normal python text
Text Block an_TextBlockSocket No Text or None
Vector an_VectorSocket Yes Vector
Vertex an_VertexSocket Yes Contains a location, normal and vertex group weights