1. Naming rules
2. Type rules
- 2.1. Use custom scalar types if you want to declare fields or args with specific semantic value.
- 2.2. Use Enum for fields which contain a specific set of values.
3. Field Rules (Output)
4. Argument rules (Input)
5. Rules of lists
6. Mutation rules
7. Rules of linkages between types (relationships)
- 7.1. GraphQL schema should be "hairy"
8. Authorization
- 8.1. Schema diffing based authorization
9. Other rules
- 10.1. Use markdown for documentation
A. Appendix
- A-1 Useful links
Credits

6. Mutation rules

No matter how many schemes I saw, most of the mess is in the Mutations. The following rules will allow you to make your API dry, clean and comfortable.

6.1. Use Namespace-types to group mutations within a single resource.

6.2. Go beyond CRUD – create small mutations for different business operations on resources.

6.3. Consider the ability to perform mutations on multiple items (same type batch changes).

6.4. Mutations should clearly describe all the mandatory arguments, there should be no options either-either.

6.5. In mutations, put all variables into one unique input argument.

6.6. Every mutation should have a unique payload type.