Core concepts
A Flow workflow is a graph: nodes do the work, edges decide what follows what and what is passed along. Everything else follows from those two things.
- Execute + Data
- LLM
The one property that makes Flow behave unlike a familiar flowchart: the engine does not
plan the order of steps in advance. A node runs when an incoming edge activates it. That
is where branching without skipping half the graph comes from, and parallel branches, and
the fact that the untaken side of an if is not an error.
Read in this order
Graph, nodes and ports
What a workflow is made of, and what a port is.
Wires
Ten edge types: what each carries and when it appears.
Port data types
What connects to what, and where coercion kicks in.
Execution order
Activation, branching, joins and barriers.
Graph boundaries
Why there is exactly one entry, and what to do with several exits.
Run statuses
completed, partial, failed — and why a node was skipped.