All nodes/Logic & Flow/Branching
If / Else
Conditional branching: evaluates an expression and routes execution to the 'true' or 'false' branch. The expression supports comparisons and access to node data: {{nodes.llm_1.output.score}} > 0.8.
Type in the graph: if
Exec
An error output can be enabled to handle failures on their own path.
Ports can be split into separate execution and data handles.
Try it
Minimal working scenario
- Execute + Data
Runs as pasted
When to use it
Reach for this node when execution forks on data the graph already has: a score from a
model, a field from a document, the length of a text, a flag from the database. There are
exactly two branches. When you need more than two directions, use switch — a chain of
five conditions reads worse than one list. When a step has to repeat while a condition
holds, that is while_loop: a link from a branch back up the graph cannot be built, the
scheduler treats such a graph as cyclic and refuses to run it.
How it works
The condition is a template, and it has two working shapes. A whole expression
inside braces ({{ nodes.classify.output.score > 0.8 }}) is evaluated and returns a real
boolean. The mixed shape ({{ nodes.classify.output.score }} > 0.8) substitutes the value
first and then parses the resulting string as one comparison of two literals: >,
>=, <, <=, ==, != and nothing else.
The node computes nothing on top of its input: the selected output carries exactly the
value that arrived. Downstream templates can read {{ nodes.<id>.output }} — that value —
and {{ nodes.<id>.branch }} — the name of the branch that fired, true or false.
The branch not taken is not a failure. Nodes on it end up skipped with the reason “An
upstream branch went the other way”, and the run still finishes as completed: run status
reports errors, not how many nodes ran.
Common mistakes
- A compound condition in the mixed shape is always true. After substitution
{{ a }} > 1 and {{ b }} < 2becomes a string that is not a single comparison — and a non-empty string is truthy. Keep the logic inside the braces:{{ a > 1 and b < 2 }}. - Text comparison belongs inside the braces too.
{{ inputs.input }} == 'yes'stops parsing as an expression after substitution and takes the true branch for any input. Write{{ inputs.input == 'yes' }}instead. - A typo in a path silently yields false. A missing path substitutes as empty, and a
comparison with an empty operand is not performed. Check what the condition became: the
run details show a Rendered templates block for the node, with the unresolved paths
listed under the
__undefined_refs__key. - An empty condition will not deploy — the expression is required.
- Both branches into one node is a normal shape. The engine runs that node once, with the payload of the branch that fired; the validator warns about it so you do not expect the values of both branches at the same time.
Inputs
| Port | Wire | Payload | Notes |
|---|---|---|---|
Inputinput | Execute + Dataexecute_data | — |
Outputs
| Port | Wire | Payload | Notes |
|---|---|---|---|
Truetrue | Execute + Dataexecute_data | — | |
Falsefalse | Execute + Dataexecute_data | — |
Configuration
| Field | Type | Default | Description |
|---|---|---|---|
Conditioncondition_expression | string | "" | Expression that evaluates to truthy/falsy. Supports comparisons: {{nodes.llm_1.output.confidence}} > 0.8 supports templates |
Shared fields
Every node has these three — the platform adds them, not the node author.
expose_error_output— When enabled, show an execution output to connect nodes that run if this step fails.split_ports_in— Show separate execution and data input handles instead of one combined port.split_ports_out— Show separate execution and data output handles instead of one combined port.