Upon reading, writing, and visualization of EnzymeML documents, the API controls data completeness and consistency, such as checking the definition of reactants and proteins upon reading or writing of a reaction, or by checking that scalar properties such as pH are within the necessary range. A specific validation tool guarantees compatibility with SBML. Further application-specific validation tools have been added, such as a STRENDA DB validator to check for compatibility with the STRENDA Guidelines. For more details, readers can find a description of API below and the Supporting Information.