JSON Payload generation with variables

Apigee Edge has an AssignMessage policy to generate custom payload. Variable delimiter in policies is curly brace {}. Example: {username}

As expected the curly brace {} is also JSON object delimiter. So generating JSON payload with variables would require change of variable prefix and suffix for Edge variables. The example below shows sample snippet to generate JSON response.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<AssignMessage async="false" continueOnError="false" enabled="true" name="buildUserDetailsResponse">
    <Set>
        <Payload contentType="text/json" variablePrefix="#" variableSuffix="%">
            {
            "name":"#username%",
            "email":"#email%"
            "adddress":#address%
            }
        </Payload>
    </Set>
    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
    <AssignTo createNew="false" transport="http" type="response"/>
</AssignMessage>

Please note the  variablePrefix and  variableSuffix attributes of the payload tag. Further, variablePrefix and  variableSuffix cannot be identical.