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Join operator


The Join operator merges two or three flows in one.

It's useful to terminate the parallel portion of a workflow.


The use of the Join operator is not mandatory, because it is also possible to directly connect two or three blocks to the same downstream block which will receive the same composite output produced by Join. However, using this operator makes the diagram more readable and tidy. If Join is used, it is suggested you start the parallel portion of the workflow with a Fork block for symmetry.

A Join block must have two or three input connections and one output connection to other blocks to be considered valid.
It can be the last block of the workflow.


The output of a Join block is the composition of the outputs of its upstream blocks and has this structure:

        first block ID:{
            first block output body
        second block ID:{
            second block output body
        third block ID:{
            third block output body

Block properties

Block properties can be set by editing the block.
A Join operator block has these properties:

  • The unique block ID and the service version, displayed in the title bar (read only, displayed also in the block tooltip in the canvas).
  • Block name