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The Input and Output variables are key when building tools in Brain Studio. They let you receive data from the flow that invokes your tool and return results when its execution finishes.

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Inputs

Input values are defined from the inputs manager while you configure your tool. Each input you declare will be available at runtime through:
  • {{$input.name}} inside any node.
  • $input.get('name', [defaultValue]) inside code nodes.
For example, if you configured an input called city: 
// Gets the city input
const city = $input.get('city')

// Gets the city input
// If not found, sets the value to 'New York'
const city = $input.get('city', 'New York')

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Outputs

The outputs of a tool are defined from a code node using $output.set(key, value). These values become available to the flow after the tool finishes. 
const data = $memory.get('apiResponse')
$output.set('data', data)
You can set multiple outputs by calling $output.set multiple times (one per key).
Make sure the names you use in $output.set('key', value) match the outputs you declared in the tool’s end node; that way the flow can consume them without errors.