Standard InChI generation

What is the right way to calculate the Standard InChI and Key?

For example, chemicalize.org does not give a Standard InChI Key for this SMILES: NCC1CC1C(O)=O

However, NIST does. 

Is this related to this topic? 

How can I get Standard InChI with ChemAxon that matches NIST?

Hi,

You can use the molconverter tool:
molconvert "inchi:AuxNone,Woff,SAbs" -s "NCC1CC1C(O)=O" will give the desired result. Documentation of molconverter usage can be found here: MolConverterDocumentation. Export option for inchi format can be found here: InchiExportOptions. If you have any more questions feel free to ask.

Regards,
Domi