Built-in Functions

Numaflow provides some built-in functions that can be used directly.

Cat

A cat builtin UDF does nothing but return the same messages it receives, it is very useful for debugging and testing.

spec:
  vertices:
    - name: cat-vertex
      udf:
        builtin:
          name: cat

Filter

A filter built-in UDF does filter the message based on expression. payload keyword represents message object. see documentation for expression here

spec:
  vertices:
    - name: filter-vertex
      udf:
        builtin:
          name: filter
          kwargs:
            expression: int(object(payload).id) > 100