JSON Systems provide 3 ways to generate JSON Schema from JSON
JsonSchema.net is a modern web application for generating JSON Schema from JSON. JSON Schema is generated according to the JSON Schema Validation: A Vocabulary for Structural Validation of JSON. A number of features make generating schemas quick and easy
If you've found a bug or have a feature request, please open a new issue.
The same API that powers JsonSchema.Net is available to developers to automate JSON schema generation The API is available as both a REST API and gRPC API. If you would like to know more please email help@jsonschema.net.
The jsn application is a modern CLI for generating JSON Schema from JSON and is available for Mac OS, Windows,
and Linux. If you would like to know more please email help@jsonschema.net. Below is the command-line help output of the
JSON Schema CLI and should give you a feel for its functionality.
The jsn generate-schema command.
To get started you need only provide the path to your JSON document.
Example:
$ jsn generate-schema example.json
To control which keywords appear in the JSON Schema, use the --keywords flag.
Example:
$ jsn generate-schema example.json --keywords="additionalItems,additionalProperties,type"
If specified in the --keywords flag, the value of individual keywords can be controlled using keyword specific flags.
Example:
$ jsn generate-schema example.json --keywords="properties,additionalProperties" --additional-properties=false
As an alternative to parameters, a configuration file can be used to control the resulting schema.
Example:
$ jsn generate-schema example.json --config=config.yaml
The configuration file can be overwritten using command line flags.
Example:
$ jsn generate-schema example.json --config=config.yaml --no-pretty=false
Usage:
jsn generate-schema JSON_FILE [flags]
Examples:
jsn generate-schema example.json
jsn generate-schema example.json --no-pretty=false
jsn generate-schema example.json --keywords="additionalItems,additionalProperties,type"
jsn generate-schema example.json --config=config.yaml
jsn generate-schema example.json --config=config.yaml --no-pretty=true
Flags:
--additional-items The "additionalItems" keyword value (default true)
--additional-properties The "additionalProperties" keyword value (default true)
--array-rule string The rule to use for the "items" keyword (default "type"). Can be one of "empty", "first", "tuple" or "type"
- "empty", use empty schema "{}"
- "first", use the first element only to generate
- "tuple", use all elements in the array
- "type", generate a schema for each type
--base-uri string Defines a URI for the schema and the value of the "$id" keyword (default "https://example.com/root.json")
-c, --config string Config file path
--examples-rule string The rule to use for generation of "examples" keyword (default "full"). Can be one of "primitive", "compound" or "full"
- "primitive", only generate examples for string, number, boolean, null
- "compound", only generate examples for objects and arrays
- "full", generate examples for all types
-h, --help help for generate-schema
--js-types-only Use "number" for all numeric types in "type" key
--keywords strings A comma separated list of keywords to be generated. Must not contain spaces. Available values
- "additionalItems"
- "additionalProperties"
- "default"
- "description"
- "examples"
- "id"
- "items"
- "minimum"
- "properties"
- "required"
- "schema"
- "title"
- "type"
- "uniqueItems"
Consider using the "config" flag to manage keywords (default [schema,id,type,properties,items])
-p, --no-pretty Do not pretty print the output
--specification string The JSON Schema specification to use (default "201909"). Can be one of "draft04", "draft06", "draft07" or "201909"
- "draft04" use the Draft 4 JSON Schema specification
- "draft06" use the Draft 6 JSON Schema specification
- "draft07" use the Draft 7 JSON Schema specification
- "201909" use the Draft 2019-09 JSON Schema specification
--unique-items The "uniqueItems" keyword value (default false)
Global Flags:
-f, --logs-format string Specify logs format: "plain" or "json" (default "plain")
-x, --trace Trace output (very noisy logs up to trace level) not usable in normal situations
-v, --verbose Verbose output (up to debug level)JSON Schema is great, but can be verbose. For example, a single empty JSON object, {}, can be described by:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"additionalProperties": true,
"definitions": {},
"id": "http://example.com/example.json",
"properties": {
"description": "This accepts anything, as long as it's valid JSON.",
"title": "Empty Object"
},
"type": [
"object",
"null"
]
}Even schemas for small APIs can quickly become hundreds of lines long. Writing schemas by hand is tedious and time consuming, and often impractical. JSON Systems makes schema generation quick and painless. Depending on your use-case, you can choose from either the web app, CLI, or API.
Anyone wishing to generate JSON schema from JSON. Typical users are web developers and mobile app developers. Some educational institutions also use JsonSchema.Net to teach JSON Schema and the core options defined by JSON Schema Validation.
The web app, CLI, and API, can save you and anyone on your team a lot of time. If your software uses JSON, it's good practice to validate any (JSON) data it receives, against a schema. A CLI and API are aimed for teams wishing to integrate JSON Schema with their software or processes.
JSON Schema specificaiton is split into three parts
JsonSchema.net follows the Validation part of the overall specification. However, the extent to which this is true changes between specifications as keywords move between Core, Validation, and Hyper-Schema. json-schema.org/specification.html is a good place to learn more.
Versioning of JSON Schema specifications can be confusing. json-schema.org maintains a helpful list of specification-links. In reverse chronological order:
Each version updates (to varying degrees) the three parts of JSON Schema specification: Core, Validation, and Hyper-Schema.
In January 2022, a new version of the JSON Schema web app was launched. This new version was a complete rewrite of the web app and brought with it many new features and bug fixes.
No, accounts and account details were not migrated to the new version.
JsonSchema.net recently underwent a complete rewrite, in the process it was announced that previously generated schemas will not be migrated to the new web app.
Please open a new issue github.com/jsonsystems/public/issues.
Great. Please open a new issue github.com/jsonsystems/public/issues.
While there are many improvements, not all features have been ported to the new app, namely
A trial version of the CLI is available to download. This version can be used indefinitely but limits the user's JSON document to not more than 250 bytes.
Please contact help@jsonschema.net.
A library has not been published. If you're interested in using our Go library in your application pleaase contact help@jsonschemanet.
Please contact help@jsonschema.net.
The Json Schema API is available as both a REST and gRPC. In both cases the API is resource oriented.
Email: help@jsonschema.net
Our cookie policy can be read at cookies.md
Our privacy policy can be read at privacy.md