Import types

When the data already exists somewhere, don't build its type by hand. Paste a sample message or the other system's schema, and the type editor creates the types for you.

In the type editor, open the Import menu and choose:

Menu item	Paste
From JSON sample	A JSON object, or an array of objects.
From YAML sample	The same data as YAML.
From JSON Schema	A JSON Schema, or an OpenAPI or Swagger document, as JSON or YAML.

Paste the text into Paste source here and click Import. The new types go into the flow's namespace; a type whose name already exists is kept as it is. Anything the importer had to simplify is listed under Imported with warnings.

From a sample

Every JSON object becomes a type. Nested objects, and objects inside arrays, become types named after their property; arrays become List fields.

{
  "orderId": 10045,
  "customer": { "name": "Ana Horvat", "email": "[email protected]" },
  "lines": [ { "sku": "A-100", "quantity": 2, "price": 19.90 } ],
  "express": true
}

gives the types NewType (the root), Customer and Lines. Rename the root after the import.

JSON value	Field type
whole number	Int64, nullable
other number	Decimal, nullable
true / false	Boolean, nullable
text, null or mixed values	String
object	a new type
array	a List of the item type

Field names are turned into C# names (orderId becomes OrderId) and the original JSON name is kept as the Serialization name, so the type reads and writes the same JSON. Paste an array of several objects to merge their fields into one type. Samples don't carry formats: change dates and identifiers from String to DateTimeOffset or Guid after the import when you need them typed.

YAML samples work the same way.

From a JSON Schema or OpenAPI document

The importer reads JSON Schema 2020-12 and earlier drafts. From an OpenAPI or Swagger document it imports every schema under components/schemas (or definitions).

Schema	Field type
string, format: date-time	DateTimeOffset
string, format: date	DateOnly
string, format: uuid	Guid
string, format: byte or base64 content	byte array
string	String
integer, format: int32	Int32
integer, format: uint64	UInt64
integer	Int64
number, format: float / double	Single / Double
number	Decimal
object with additionalProperties	Dictionary
object, allOf	a type
integer enum	an enum, member names from x-enum-varnames or x-enumNames
string enum	String

Properties that are not required become nullable. Defaults and descriptions are taken over. Constructs a C# type can't express directly - oneOf / anyOf over different types, tuples, references to other documents - become fields that hold any JSON value, with a warning.

A JSON Schema exported from Viaducta imports back into exactly the same types, so you can move a contract between installations or keep it in version control.