Control nodes help your workflow make decisions and branch based on conditions or variable values. Siren currently supports two types of control nodes:
  • If Node — used for binary conditions (true/false paths)
  • Switch Node — used for multi-branch routing based on values

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If Node

The If Node allows you to define one or more conditions, and split the workflow based on whether the condition(s) evaluate to true or false. If Node

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Basic Workflow Configuration

In a Basic workflow, you can configure only one condition. Each condition has the following fields:
  • Value A – This is the input source, typically a JSON path pointing to data pulled from your system, database, or even a prior node.
  • Type – The expected data type for comparison, such as STRING, NUMBER, or BOOLEAN.
  • Comparison Operator – How you want to compare the two values. Options include EQUALS, NOT EQUALS, GREATER THAN, etc.
  • Value B – The reference value you are comparing against. This is usually the value entered by the user or a static condition. If the condition evaluates to true, the workflow continues along the true path. Otherwise, it follows the false path.

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Advanced Workflow Configuration

In an Advanced workflow, the If Node becomes more powerful. You can:
  • Add multiple conditions
  • Combine them using AND / OR logic
  • Use dynamic data from external APIs or workflow input using JSON paths

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Example

Imagine you need to send notification to a user whose ID is verified and check their country if India use one provider, if USA use another provider. So use the if node in advanced workflow for this.
  • A user submits their country, and if their ID is verified or not verified.
  • Your backend fetches the corresponding details of the user from the database and passes it to Siren.
You can configure the If Node like this:
  • Value A: ${workflow.input.data.country} (value retrieved from your database)
  • Type: STRING
  • Operator: EQUALS
  • Value B: India (the Country the user entered)
This checks if the submitted country matches the required one. The other branch can look like this, where Value A fetches from the database whether the person’s ID is verified or not.
  • Value A: ${workflow.input.data.verification}
  • Type: STRING
  • Operator: EQUALS
  • Value B: verified
These conditions can then be combined using AND logic — so the workflow proceeds only if both checks pass.

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Switch Node

The Switch Node is used to split the workflow into multiple paths based on the value of a variable, similar to a switch-case logic in programming. Switch Node

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Basic Workflow Configuration

In Basic mode, the switch has a Name field and allows defining up to 9 cases, including a default (fallback) case.
  • Each case is a static value.
  • You can route each case to a different set of nodes.
  • The default route will be used if no match is found.

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Advanced Workflow Configuration

In an Advanced workflow, you will see a Switch Expression field instead of a name.
  • Enter a JSON variable path (e.g., ${workflow.input.data.}) to evaluate dynamically.
  • Add up to 9 cases to match the expression.
  • Just like in Basic mode, one fallback case is always present by default.

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Example

Suppose you want to notify users based on their preferred channel.
  • Use ${workflow.input.data.channel} as your Switch Expression
  • Add cases like email, sms, and push
  • Connect each case to the respective channel’s template node
  • Let the fallback case handle any unknown or missing channel values
This allows you to streamline multi-channel workflows in a clean, organized way.