Write TypeSpec, emit OpenAPI
Emitting OpenAPI from TypeSpec enables seamless cross-language interaction, automates API-related tasks, and simplifies API management and evolution.
Get started 
import "@typespec/http";


using Http;


model Pet {
  name: string;
  age: int32;
}


model Store {
  name: string;
  address: Address;
}


model Address {
  street: string;
  city: string;
}


@route("/pets")
interface Pets {
  list(@query filter: string): Pet[];
  create(@body pet: Pet): Pet;
  read(@path id: string): Pet;
}


@route("/stores")
interface Stores {
  list(@query filter: string): Store[];
  read(@path id: string): Store;
}
Ecosystem
Interoperate with the OpenAPI ecosystem
Benefit from a huge ecosystem of OpenAPI tools for configuring API gateways, generating code, and validating your data.
Linters
Integrate with spectral to lint your OpenAPI.
Learn more →
 
@service(#{ title: "Pet Store Service" })
namespace PetStore;


op ping(): void;
openapi: 3.0.0
info:
  title: Pet Store Service
  version: 2021-03-25
tags: []
paths:
  /:
    get:
      operationId: ping
      parameters: []
      responses:
        "204":
          description: "There is no content to send for this request, but the headers may be useful. "
components: {}
data:text/plain;base64,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
Ecosystem
Abstract recurring patterns
Transform API patterns into reusable elements to enhance both the quality and uniformity of your API interface.
Example: TypeSpec Azure Library
The TypeSpec library for Azure allows multiple teams to reuse pre-approved patterns.
Learn more →
 
import "@typespec/http";


using Http;


// Define abstraction for resource lifecyle
op ResourceList<T>(@query filter: string): T[];
op ResourceRead<T>(@path id: string): T;
@post op ResourceCreate<T>(...T): T;


model Pet {
  name: string;
  age: int32;
}


@route("/pets")
interface Pets {
  list is ResourceList<Pet>;
  create is ResourceCreate<Pet>;
  read is ResourceRead<Pet>;
}