Pins & nodes basics
Every Flovello pipeline is a graph of nodes wired together by pins. This tutorial covers just the basics: adding a node, telling the two kinds of pins apart, and connecting them. For a deeper dive, see the guides linked at the end.
Adding a node
Right-click anywhere on the canvas and choose Add node from the menu. This opens the node selector — search for a node by name and click it to place it on the canvas.
Two kinds of pins
Every node has one or more pins on its sides, and they come in two categories:
Execution pin
A white triangle that controls when a node runs. Wire one to enforce execution order.
Argument pin
A colored circle that passes data between nodes. Color indicates the data type.
Execution pins (white triangles) control the order nodes run in. An execution connection from node A to node B means "run B after A finishes." Nodes with execution pins are called action nodes — they have a side effect, such as writing a log entry or making an HTTP request.
Argument pins (colored circles) carry typed data between nodes. Their color tells you the data type — for example pink for strings, green for integers. Argument connections have no effect on run order by themselves.
Connecting pins
To wire two nodes together, drag from an output pin on one node to a compatible input pin on the other. Execution pins only connect to execution pins; argument pins only connect to argument pins of a matching type.
Generic pins
Some pins don't have a fixed type — they show up slate/gray and are called generic. A generic pin resolves to a concrete type the moment you make its first connection. The For each node is a good example: its element output starts out generic, then takes on whichever type its array input is wired to — connect a string array and element becomes a string pin; connect an integer array and it becomes an integer pin.
Pure vs. action nodes
Nodes that have execution pins are action nodes — they participate in run order and usually have a side effect. Nodes with only argument pins and no execution pins are pure nodes — they simply compute a value from their inputs, and Flovello evaluates them lazily, only when something downstream actually reads their output.
Want more detail?
- Build your first pipeline walks through creating and running a complete pipeline end to end.
- How execution flow works is a deeper dive on execution pins, pure nodes, and lazy evaluation.