Mapping from bigpipe to API?

Yes, I do work for F5. I'm assuming that you don't 😎 .

A map from bigpipe commands to their iControl counterparts is a great idea. It was thought that the mapping was fairly straight forward but it seems that a more documented mapping would be beneficial. I will look at creating a a technical article for this website in the near future that will provide a dynamic lookup. In the short term, feel free to post your specific mapping questions here. Here are the iControl methods for your examples

bigpipe snat map default to auto unit 1

 
 Method create_default_ex 
  
 Creates a default SNAT map with a unit ID and netmask.  
  
 void ITCMLocalLB::SNAT::create_default_ex( 
     String translated_addr, 
     long unit_id, 
     String netmask 
 ); 
 

bigpipe self 166.71.142.83 snat automap enable

 
 Method set_snat_automap 
  
 Sets the SNAT automap state of the specified self IP.  
  
 void ITCMNetworking::SelfIP::set_snat_automap( 
     in String self_ip, 
     in EnabledState state 
 );