alloy

This trait indicates that a String value contains a date without a time component. Following the RFC-3339 (an extension of ISO 8601), the default for a date is the following: date-fullyear = 4DIGIT date-month = 2DIGIT ; 01-12 date-mday = 2DIGIT ; 01-28, 01-29, 01-30, 01-31 based on ; month/year full-date = date-fullyear "-" date-month "-" date-mday

See: https://www.rfc-editor.org/rfc/rfc3339#section-5.6 e.g.: "2022-03-30" If a time component is required, you can use smithy.api#Timestamp

Use this trait to give a default value to a structure member. This is not the same as smithy.api#default which is more constrained. You can use defaultValue to specify a default that does not align with the target's shape constraints, where as Smithy's default trait prevents that. For example:

@length(min:5)
string MyString
structure MyStruct {
 @defaultValue("N/A") // that's valid
 s1: MyString
 s2: MyString = "N/A" // that's invalid
}

Discriminated unions contain the information about which branch of a union is encoded inside of the object itself. The following union: structure One { a: Int } structure Two { b: String } union Test { one: One two: Two } would normally be encoded in JSON as: { "one": { "a": 123 } } when annotated with @discriminated("type"), it will instead be encoded as: { "a": 123, "type": "one" } This is more efficient than using an untagged encoding, but less efficient than using the default tagged union encoding. Therefore, it should only be used when necessary. Tagged union encodings should be used wherever possible.

Use this trait to mark some field as nullable. This is to make a distinction between an optional field that is missing and one that's explicitly set to null.

A rest protocol that deals with JSON payloads only in HTTP requests and responses. These are encoded with the content type application/json. See Alloy documentation for more information.

Implies a different encoding for unions where different alternatives are not tagged. This union type should be avoided whenever possible for performance reasons. However, some third party APIs use it so it is important to be able to represent it. The following union: structure One { a: Int } structure Two { b: String } union Test { one: One two: Two } would normally be encoded in JSON as { "one": { "a": 123 } } When it is annotated with @untagged, it is instead encoded as: { "a": 123 }. Therefore the parser will need to try each different alternative in the union before it can determine which one is appropriate.

UUID v4 compliant with RFC 4122

Use this trait to give a default value to a structure member. This is not the same as smithy.api#default which is more constrained. You can use defaultValue to specify a default that does not align with the target's shape constraints, where as Smithy's default trait prevents that. For example:

@length(min:5)
string MyString
structure MyStruct {
 @defaultValue("N/A") // that's valid
 s1: MyString
 s2: MyString = "N/A" // that's invalid
}

Discriminated unions contain the information about which branch of a union is encoded inside of the object itself. The following union: structure One { a: Int } structure Two { b: String } union Test { one: One two: Two } would normally be encoded in JSON as: { "one": { "a": 123 } } when annotated with @discriminated("type"), it will instead be encoded as: { "a": 123, "type": "one" } This is more efficient than using an untagged encoding, but less efficient than using the default tagged union encoding. Therefore, it should only be used when necessary. Tagged union encodings should be used wherever possible.