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Hydra DSL›1 · Manifest›version
Grammar element · version

version declares an intent, not a contract

Two correct manifests, with the line and without. Walk them, then read what the key is for.

sources.yaml4 steps

      

    

    

      
      
      
    

    

      
      
    

  


  

    

      
      
What the engine does with it
The same run in both cases. That is the point of this page.

    

    

    

    

      ✓ 30 rows read · 6 written
      
    

  



 

  
What version is

  

    version is the first line of a manifest file. It states which shape of the language
    the file was written for — a declaration of intent addressed to whoever reads the file next,
    human or tool.
  

  

    It is not a contract. Hydra has published one shape of the language so far, and the engine does not
    branch on this key: no job parser reads it. Remove it from all four files of a working job and the
    run is identical. Write "2.0" and nothing selects another grammar, because none exists.
  


  

    
      Which reader looks at the version key
      Job parsers ignore version entirely; the workflow model stores it and compares it to nothing.

      the key
      who reads the file
      what it does with it

      
      version:
      "1.0"
      first line of the file

      
      

      
      the four job parsers
      sources · transformations · destinations · pipeline

      
      the workflow model
      workflow.yaml

      
      

      
      never read

      
      stored
      compared to nothing

      Removing the line from a working job changes nothing: 30 rows read, 6 written, as before.

      
        
          
        
      
    
    
One key, two readers, and neither one acts on it.

  


  
What to do with it

  
    
    
  • Write it anyway. A manifest without a version says nothing about its age. Cost: one line.
    • 
    
  • Write "1.0". It is the only shape published, and every example uses it.
    • 
    
  • Do not expect a check. Nothing verifies the value, so it cannot protect you from anything.
    • 
    
  • Do not use it as a feature flag. Nothing in the engine branches on it.
    • 
  


  
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