Branching with Ports and Expressions

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# nodes/my_prompt_node.py
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class MyNode(BaseNode):
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    # ... prompt node attributes go here ...
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    class Ports(BaseNode.Ports):
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        first_condition = Port.on_if(condition_expression)
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        second_condition = Port.on_elif(another_condition)
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        fallback = Port.on_else()
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# workflow.py
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class MyWorkflow(BaseWorkflow):
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    graph = {
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        # Can route to nodes or other Workflows
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        MyPromptNode.Ports.first_condition >> MyOtherNode,
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        MyPromptNode.Ports.second_condition >> AnotherNode1,
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        MyPromptNode.Ports.fallback >> AnotherNode2,
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    }
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    class Outputs(BaseWorkflow.Outputs):
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        final_output = MyOtherNode.Outputs.output

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from vellum.workflows.nodes.displayable import InlinePromptNode
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from vellum.workflows.ports import Port
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from vellum.workflows.references import LazyReference
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class SentimentAnalysisNode(InlinePromptNode):
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    # ... inline prompt node attributes go here ...
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    class Ports(InlinePromptNode.Ports):
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        # Self-referencing port condition
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        positive = Port.on_if(
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            LazyReference(lambda: SentimentAnalysisNode.Outputs.json["sentiment"].equals("positive"))
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        )
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        negative = Port.on_elif(
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            LazyReference(lambda: SentimentAnalysisNode.Outputs.json["sentiment"].equals("negative"))
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        )
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        else_port = Port.on_else()
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# workflow.py
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class MyWorkflow(BaseWorkflow):
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    graph = {
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        SentimentAnalysisNode.Ports.positive >> MyOtherNode,
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        SentimentAnalysisNode.Ports.negative >> AnotherNode1,
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        SentimentAnalysisNode.Ports.else_port >> MyOtherNode,
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    }
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    class Outputs(BaseWorkflow.Outputs):
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        final_output = MyOtherNode.Outputs.output

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# Basic equality
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Port.on_if(Inputs.category.equals("question"))
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Port.on_if(SomeNode.Outputs.status.does_not_equal("error"))
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# String comparisons
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Port.on_if(Inputs.text.contains("keyword"))
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Port.on_if(Inputs.text.does_not_contain("spam"))
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Port.on_if(Inputs.filename.begins_with("temp_"))
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Port.on_if(Inputs.filename.does_not_begin_with("system"))
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Port.on_if(Inputs.url.ends_with(".pdf"))
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Port.on_if(Inputs.url.does_not_end_with(".tmp"))

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# Numeric operators
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Port.on_if(Inputs.score.greater_than(0.8))
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Port.on_if(Inputs.count.less_than(100))
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Port.on_if(Inputs.rating.greater_than_or_equal_to(4.0))
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Port.on_if(Inputs.attempts.less_than_or_equal_to(3))
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# Range checks
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Port.on_if(Inputs.temperature.between(20, 30))
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Port.on_if(Inputs.age.not_between(13, 17))

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# Membership testing
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Port.on_if(Inputs.status.in_(["active", "pending"]))
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Port.on_if(Inputs.category.not_in(["spam", "deleted"]))

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# Null checks
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Port.on_if(Inputs.optional_field.is_null())
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Port.on_if(Inputs.required_field.is_not_null())
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# Nil checks (empty/blank values)
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Port.on_if(Inputs.description.is_nil())
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Port.on_if(Inputs.title.is_not_nil())
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# Undefined checks
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Port.on_if(Inputs.config_value.is_undefined())
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Port.on_if(Inputs.user_input.is_not_undefined())
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# Blank checks (empty strings, whitespace)
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Port.on_if(Inputs.comment.is_blank())
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Port.on_if(Inputs.name.is_not_blank())

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# JSON parsing
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Port.on_if(Inputs.json_string.parse_json())
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# Coalescing (fallback values)
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Port.on_if(Inputs.primary_value.coalesce(Inputs.fallback_value))

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# Access JSON object fields
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Port.on_if(PromptNode.Outputs.json["status"].equals("success"))
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Port.on_if(APINode.Outputs.response["data"]["count"].greater_than(10))
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# Combine with LazyReference for self-referencing
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Port.on_if(LazyReference(lambda: DataProcessorNode.Outputs.result)["confidence"].greater_than(0.8))
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# Check nested JSON values
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Port.on_if(Inputs.config["settings"]["enabled"].equals(True))
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Port.on_if(CodeNode.Outputs.analysis["metrics"]["accuracy"].between(0.8, 1.0))

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Port.on_if(
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    Inputs.category.equals("urgent") 
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    & Inputs.priority.greater_than(5)
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)
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# Complex AND with parentheses
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Port.on_if(
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    Inputs.status.equals("active")
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    & (Inputs.verified.equals(True) & Inputs.premium.equals(True))
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)

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Port.on_if(
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    Inputs.category.equals("error") 
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    | Inputs.category.equals("warning")
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)
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# Mixed AND/OR with proper precedence
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Port.on_if(
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    Inputs.type.equals("admin")
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    & (Inputs.role.equals("owner") | Inputs.role.equals("manager"))
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)

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# Parentheses control precedence
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Port.on_if(
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    (
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        Inputs.user_type.equals("premium")
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        & Inputs.subscription.equals("active")
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    )
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    | Inputs.admin_override.equals(True)
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)