Working with other API specs

OpenAPI Integration

Overview

Taxi can be embedded within OpenAPI specifications to add semantic meaning to APIs. This allows you to:

  • Define semantic types for request/response models
  • Add semantic meaning to API parameters
  • Create a unified semantic layer across multiple APIs

Semantic Enhancement

OpenAPI specs describe API structure. Taxi enhances them with semantic meaning, enabling better data discovery and integration.

Adding Taxi to OpenAPI

Basic Syntax

Taxi metadata is added using x-taxi-type extensions in your OpenAPI spec:

x-taxi-type:
  name: com.acme.MyType    # The semantic type name
  create: false            # Optional flag to control type creation

Type Creation Behavior

The create flag controls whether new types are created if they don’t exist.

The default behaviour varies between models and field attributes - and defaults to the reccomended best practice for each.

ContextDefaultBehavior
Response ModelstrueCreates new types if not found
Field AttributesfalseRequires types to exist

Type Creation

Declaring operation kinds

Some TaxiQL behavior depends on whether operations are read-only or write operations (sometimes referred to as ‘mutations’).

By default:

  • GET, HEAD, and OPTIONS methods are treated as read operations (default, no modifier)
  • POST, PUT, PATCH, and DELETE methods are treated as write operations

You can override this default behavior using x-taxi-operation-kind at the operation level:

   openapi: "3.0.0"
   info:
     version: 1.0.0
     title: Swagger Petstore
   paths:
     /pets:
       # POST operations are 'write' by default, but this can be overridden
       post:
         x-taxi-operation-kind: read  # Override to make a POST operation read-only
         responses:
           '200':
             description: successful operation
             content:
               application/json:
                 schema:
                   type: object
                   properties:
                     name:
                       type: string
       
       # GET operations are 'read' by default, but this can be overridden
       get:
         x-taxi-operation-kind: write  # Override to make a GET operation a write operation
         responses:
           '200':
             description: successful operation
             content:
               application/json:
                 schema:
                   type: object
                   properties:
                     name:
                       type: string

Possible values for x-taxi-operation-kind:

  • read - The operation is read-only (default for GET, HEAD, OPTIONS)
  • write - The operation modifies data (default for POST, PUT, PATCH, DELETE)

Enriching OpenAPI Components

Response Models

Add semantic meaning to response types:

components:
  schemas:
    Customer:
      x-taxi-type:
        name: acme.Customer
      properties:
        id: 
          type: string
          x-taxi-type:
            name: acme.CustomerId
        email:
          type: string
          x-taxi-type:
            name: acme.EmailAddress

Input Parameters

Enrich API parameters with semantic types:

paths:
  /customers/{id}:
    get:
      parameters:
        - name: id
          in: path
          schema:
            type: string
            x-taxi-type:
              name: acme.CustomerId

Field Attributes

Add semantic meaning to model fields:

components:
  schemas:
    Customer:
      properties:
        name:
          type: string
          x-taxi-type:
            name: acme.CustomerName
            # Only create if type doesn't exist
            create: true
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