Tool to generate JSON schema from JSON data [closed]

Answer 1

Seeing that this question is getting quite some upvotes, I add new information (I am not sure if this is new, but I couldn't find it at the time)

• The home of JSON Schema
• An implementation of JSON Schema validation for Python
• Related hacker news discussion
• A json schema generator in python, which is what I was looking for.

Answer 2

There's a python tool to generate JSON Schema for a given JSON: https://github.com/perenecabuto/json_schema_generator

Answer 3

generate-schema (NPM | Github) takes a JSON Object generates schemas from it, one output is JSON Schema, it's written in Node.js and comes with a REPL and ClI tool for piping files into.

Full Disclosure: I'm the author :)

Answer 4

Summarising the other answers, here are the JSON schema generators proposed so far:

Online:

• https://www.liquid-technologies.com/online-json-to-schema-converter (1 input)
• http://www.jsonschema.net (1 input)
• https://easy-json-schema.github.io (1 input)

Python:

• https://github.com/gonvaled/jskemator (1 input but allows iteration)
• https://github.com/perenecabuto/json_schema_generator (1 input)
• https://github.com/rnd0101/json_schema_inferencer (1 input I think)
• https://pypi.python.org/pypi/genson/ (multiple inputs)
• https://pypi.python.org/pypi/skinfer (multiple inputs)

NodeJS:

• https://github.com/Nijikokun/generate-schema (multiple inputs (pass object array))
• https://github.com/easy-json-schema/easy-json-schema (1 input)
• https://github.com/aspecto-io/genson-js (multiple inputs)

Ruby:

• https://github.com/maxlinc/json-schema-generator (1 input)

Answer 5

For the offline tools that support multiple inputs, the best I've seen so far is https://github.com/wolverdude/GenSON/ I'd like to see a tool that takes filenames on standard input because I have thousands of files. However, I run out of open file descriptors, so make sure the files are closed. I'd also like to see JSON Schema generators that handle recursion. I am now working on generating Java classes from JSON objects in hopes of going to JSON Schema from my Java classes. Here is my GenSON script if you are curious or want to identify bugs in it.

#!/bin/sh
ulimit -n 4096
rm x3d*json
cat /dev/null > x3d.json
find ~/Downloads/www.web3d.org/x3d/content/examples -name '*json' -      print| xargs node goodJSON.js | xargs python bin/genson.py -i 2 -s     x3d.json >> x3d.json
split -p '^{' x3d.json x3d.json
python bin/genson.py -i 2 -s x3d.jsonaa -s x3d.jsonab /Users/johncarlson/Downloads/www.web3d.org/x3d/content/examples/X3dForWebAuthors/Chapter02-GeometryPrimitives/Box.json > x3dmerge.json 

Answer 6

After several months, the best answer I have is my simple tool. It is raw but functional.

What I want is something similar to this. The JSON data can provide a skeleton for the JSON schema. I have not implemented it yet, but it should be possible to give an existing JSON schema as basis, so that the existing JSON schema plus JSON data can generate an updated JSON schema. If no such schema is given as input, completely default values are taken.

This would be very useful in iterative development: the first time the tool is run, the JSON schema is dummy, but it can be refined automatically according to the evolution of the data.