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This project implements a language-independent set of formal transformations to automatically transform JSON Schema documents across versions of the specification.

Try the web playground at:


From To Type Status Description
2019-09 2020-12 Lossless Full JSON Schema 2019-09 to JSON Schema 2020-12
draft7 2019-09 Lossless Full JSON Schema Draft 7 to JSON Schema 2019-09
draft6 draft7 Lossless Full JSON Schema Draft 6 to JSON Schema Draft 7
draft4 draft6 Lossless Full JSON Schema Draft 4 to JSON Schema Draft 6
draft3 draft4 Lossless Minimal 1 JSON Schema Draft 3 to JSON Schema Draft 4

Transformations are transitively applied. For example, transforming from draft6 to 2019-09 implies transforming draft6 to draft7 and draft7 to 2019-09.



// (1) Install by running "npm install --save alterschema"
const alterschema = require('alterschema')

// (2) alterschema(schema: JSON, from: string, to: string) -> JSON
// Transform the input document `schema` according to the
// `from` and `to` string parameters.
const result = await alterschema({ ... }, '2019-09', '2020-12')


Command-line tool

# (1) Install globally through npm
npm install --global alterschema
# (2) Run the command-line tool
alterschema --from <from> --to <to> path/to/schema.json


We accept contributions to implement alterschema in any programming language. To produce an alterschema implementation, your programming language of choice must support a JSON Schema 2020-12 validator and a JSON-e interpreter.


Special thanks to @gregdeniss for curating the initial set of upgrade rules.


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