Dynamic Response Playground
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Template Syntax Reference

                        
Universal interpolation engine supporting JSON & XML payloads

                    

                


                
            


            

                
                

                    

                        1. Built-in Dynamic Generators
                    

                    

                        

                            
                                

                                    Keyword / Function
                                    Output Type
                                    Sample Output
                                

                            
                            
                                

                                    {{ $uuid }}
                                    UUID v4 (String)
                                    "01a167be-492b-711f..."
                                

                                

                                    {{ $timestamp }}
                                    Epoch Seconds (Number)
                                    1729676452
                                

                                

                                    {{ $timestamp_ms }}
                                    Epoch Millis (Number)
                                    1729676452189
                                

                                

                                    {{ $time('%Y-%m-%d %H:%M:%S') }}
                                    Formatted Datetime (String)
                                    "2026-10-24 07:38:19"
                                

                                

                                    {{ $random_int(1000, 9999) }}
                                    Bounded Random (Number)
                                    5428
                                

                                

                                    {{ $random_str(8) }}
                                    Random Alphanumeric (String)
                                    "xI12uM9K"
                                

                            
                        

                    

                


                
                

                    

                        2. Request Context Extraction (JSON & XML)
                    

                    

                        

                            req.body.*
                            
Navigates both JSON and XML request structures seamlessly. Supports dot notation, nested tags, and XML attributes: {{ req.body.customer.name }} or {{ req.body.order.@id }}

                        

                        

                            req.query.*
                            
Reads URL query parameters: {{ req.query.search }}

                        

                        

                            req.headers.*
                            
Reads HTTP headers case-insensitively: {{ req.headers.authorization }}

                        

                    

                


                
                

                    

                        3. Transformers & Array Slicing
                    

                    

                        

                            
                                

                                    Modifier Syntax
                                    Description
                                    Example Output
                                

                            
                            
                                

                                    {{ $upper(req.body.name) }}
                                    Converts value to UPPERCASE
                                    "ALEX MORGAN"
                                

                                

                                    {{ $lower(req.headers.auth) }}
                                    Converts value to lowercase
                                    "bearer token"
                                

                                

                                    {{ $split(req.body.name, ' ')[0] }}
                                    Splits string by delimiter and extracts element at index
                                    "Alex"
                                

                                

                                    {{ req.body.tags[0:2] }}
                                    Slices array from start up to end index (exclusive)
                                    ["premium", "verified"]
                                

                            
                        

                    

                


                
                

                    ℹ
                    

                        Type-Aware Unwrapping & Strict Null Safety
                        
Tokens resolve natively according to their extracted JSON data types:

                        
    
                            
  • Standalone Quoted: Tokens enclosed entirely within quotes ("{{ req.body.missing }}") automatically unwrap surrounding quotes when resolving to JSON null, booleans, numbers, or arrays/objects, preventing string literal "null" leakage.
    • 
                            
  • Embedded Interpolation: Missing tokens inside composite strings ("ID-{{ req.body.missing }}") fallback cleanly to an empty string "" ("ID-") without corrupting text flow.
    • 
                        

                    

                

            


            

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