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0536 API Schemas

The schema of a deployed API is its interface definition. The open metadata types for an API's schema were influenced by the OpenAPI Specification standard.

Model 0536 shows the structure of an API schema. The top level schema for the API lists the operations. Under that, each operation defines its requests and responses.

UML

APISchemaType

The APISchemaType entity provides the RootSchemaType for the API's schema.

APIOperations

The APIOperations relationship links the APISchemaType entity to one of its operations, represented by the APIOperation entity.

APIOperation

The APIOperation entity represents a single operation (also known as a method, or function). If this is a ReSt API, set the pathName variable to the path of the operation. Add the name of the operation/function/method to the command attribute.

APIHeader

Some operations include header information that supplied runtime information such as security tokens or debug levels. The structure of the supported header information can be documented in a SchemaType that is linked to the APIOperation entity via the APIHeader relationship.

APIRequest

The structure of the request parameters for an operation can be documented in a SchemaType that is linked to the APIOperation entity via the APIRequest relationship. Typically, the type of the request parameters is APIParameterList.

APIResponse

The structure of the response (results) of an operation can be documented in a SchemaType that is linked to the APIOperation entity via the APIResponse relationship.

APIParameterList

The APIParameterList entity is a specialized ComplexSchemaType that allows a list of parameters to be defined.

APIParameter

The APIParameter entity is a specialized SchemaAttribute that indicates that the parameter is part of an API. It helps consumers of the metadata to understand the difference between, for example, ta data element send on an API from a database column stored in a database.

Example API Schema

Here is an example of an API schema called CustomerAPI Specification. It shows one API operation called getCustomer. This operation takes a customerNo string as an input parameter and returns customerNo, customerName and customerCardId strings in the response.

Example API Schema