API Design · Junior · Question 63 of 75

Why are enums in API responses tricky to extend?

1Enums are always strings in HTTP
2Enums can't be sent in JSON
✓Correct answer: Clients may crash on unknown values; document that new values can appear and make clients handle unknowns

Explanation

Adding an enum value can be a breaking change for strict clients. Some guidelines treat output enums as extensible by default.

Further reading

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