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A comment on Ask HN: Do you use JSON Schema? Help us shape its future stability guarantees. Parent comment

Re:Ask HN: Do you use JSON Schema? Help us shape its future ... by relequestual on Tuesday January 31, 2023 @05:42AM (#34593563)
Actually, currently, this is not the case. The specification explicitly allows for additional fields for the purposes of extensions. We are considering changing that, and only allowing pre-defined fields, or having a way to mark specific fields as limited extensions.
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Re:Ask HN: Do you use JSON Schema? Help us shape its future ... by Taywee on Tuesday January 31, 2023 @04:19PM (#34602317)
Huh, you're right. There is additionalProperties, but I mistakenly thought `"additionalProperties": false` was the default.
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Re:Ask HN: Do you use JSON Schema? Help us shape its future ... by relequestual on Wednesday February 01, 2023 @06:11AM (#34609028)
It is not =]

Additionally, the value is a "schema" as opposed to a boolean, meaning you can apply a subschema to any additional fields. Useful if you for instance want to make sure any additional fields start with a specific prefix.

Booleans are valid schemas. It's subschemas all the way down! I wrote an article around this topic: https://json-schema.org/blog/posts/applicability-json-schema...

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