• multiple interfaces not supported in grammar

Today multi-service architectures requires developers to keep in sync a lot of different services built in different languages by different teams. To do this manually requires a lot of work always changing the shared object types between different projects and a lot of integration tests to make sure that all the services can communicate. With skema you can have one single source of truth for your most important shared types and can generate the validation (jsonschema) and the code to serialize them and be sure the different services can communicate.

• jsonschema
• python
• graphql

• python
• typescript
• go
• rust
• c++ ...

Requires python 3.6+ and npm

pip install skema
npm i -g quicktype # for more languages

skema generate ./schema.skema --jsonschema ./your_path.json
skema generate ./schema.skema --graphql ./your_path.graphql
skema generate ./schema.skema --typescript ./your_path.graphql
# using an hosted skema
skema generate "https://gist.github.com/your_gist" --typescript ./your_path.graphql

User:
    id: Int
    name: Str
    address:
        street: Str
        number: Int
        state: Str
    credit: Float
    email: /.*@.*\.com/

Pet:
    name: Str
    friends: [Pet] # you can reference other types

Owner:
    full_name: Str
    hobbies: [
        name: Str
        when: CronString
    ]

CronString: Str

Animal: Tiger | Bear | Panthera

Panthera:
    _id: ObjectId # a type alias
    black_nuance: "super_dark" | "dark" | "light" # enumeration

Tiger:
    _id: ObjectId
    humans_killed: Int

Bear:
    _id: ObjectId
    likes_honey: Bool

ObjectId: Any

Centaur: Horse & Human

Horse:
    name: Str
    eats: ["carrots" | "weeds"]

Human:
    name: Str
    surname: Str
    eats: ["meat" | "vegetables"]

• Int
• Float
• Str
• Bool
• null
• "literal string"
• /regex/
• 0..69
• Any

• Validate json input
• Generare code types for every language in your architecture (graphql, py, ts, cpp, ...)
• Generate fake data based on your schema
• Infer schema from raw json (perfect for reverse engineering)
• convert jsonschema to be easier to read
• use it for API types documentation
• Generate react forms, via [react-skema-forms]
• use it to plan your domain model!

• all root properties are references and can be used as types
• types can be object whose properties are expressed as key: value or other primitive types like
  • Str,
  • Int,
  • Bool,
  • Float
  • /regex/
  • 0..100 (int range)
  • .0..1 (float range)
• type inside [ ] is an array type
• types can be mixed together:
  • Str | Int means one of string and int
  • Object1 & Object2 means "all the properties of object 1 and 2"
  • Object1 | Object2 means "properties of object 1 and 2"
• types can be annotated writing annotations """ quotes above the definition
• additional propertiescan be specified adding ... at the end of an object and can be better shaped treating it like a normal key, ...: Str means additional properties must be Str