@samchon/openapi

OpenAPI definitions and converters.

@samchon/openapi is a collection of OpenAPI definitions of below versions. Those type definitions do not contain every properties of OpenAPI specification, but just have only significant features essentially required for typia, nestia (especially for @nestia/editor).

1. Swagger v2.0
2. OpenAPI v3.0
3. OpenAPI v3.1

Also, @samchon/openapi provides emended OpenAPI v3.1 definition and its converter/inverter from above versions for convenient development. The keyword "emended" means that OpenApi is not a direct OpenAPI v3.1 specification (OpenApiV3_1), but a little bit shrinked to remove ambiguous and duplicated expressions of OpenAPI v3.1 for the convenience of typia and nestia.

For example, when representing nullable type, OpenAPI v3.1 supports three ways. In that case, OpenApi remains only the third way, so that makes typia and nestia (especially for @nestia/editor) to be simple and easy to implement.

• { type: ["string", "null"] }
• { type: "string", nullable: true }
• { oneOf: [{ type: "string" }, { type: "null" }] }

flowchart
  v20(Swagger v2.0) --upgrades--> emended[["<b><u>OpenAPI v3.1 (emended)</u></b>"]]
  v30(OpenAPI v3.0) --upgrades--> emended
  v31(OpenAPI v3.1) --emends--> emended
  emended --downgrades--> v20d(Swagger v2.0)
  emended --downgrades--> v30d(Swagger v3.0)

Here is the entire list of differences between OpenAPI v3.1 and emended OpenApi.

• Operation
  • Merge OpenApiV3_1.IPathItem.parameters to OpenApi.IOperation.parameters
  • Resolve references of OpenApiV3_1.IOperation members
  • Escape references of OpenApiV3_1.IComponents.examples
• JSON Schema
  • Decompose mixed type: OpenApiV3_1.IJsonSchema.IMixed
  • Resolve nullable property: OpenApiV3_1.IJsonSchema.__ISignificant.nullable
  • Array type utilizes only single OpenAPI.IJsonSchema.IArray.items
  • Tuple type utilizes only OpenApi.IJsonSchema.ITuple.prefixItems
  • Merge OpenApiV3_1.IJsonSchema.IAnyOf to OpenApi.IJsonSchema.IOneOf
  • Merge OpenApiV3_1.IJsonSchema.IRecursiveReference to OpenApi.IJsonSchema.IReference
  • Merge OpenApiV3_1.IJsonSchema.IAllOf to OpenApi.IJsonSchema.IObject

Additionally, @samchon/openapi provides IHttpMigrateApplication for OpenAPI generators.

If you're developing TypeScript, @nestia/editor would be the best project utilizing the IHttpMigrateApplication for the OpenAPI SDK generation. Otherwise, you wanna utilize OpenAPI document for OpenAI function calling, @wrtnio/openai-function-schema has been prepared for you.

flowchart
  subgraph "OpenAPI Specification"
    v20(Swagger v2.0) --upgrades--> emended[["OpenAPI v3.1 (emended)"]]
    v30(OpenAPI v3.0) --upgrades--> emended
    v31(OpenAPI v3.1) --emends--> emended
  end
  subgraph "OpenAPI Generators"
    emended --normalizes--> migration[["<b><u>Migration Schema</u></b>"]]
    migration --A.I.--> lfc{{"LLM Function Call"}}
    migration --Uiltiy--> editor{{"@nestia/editor"}}
  end

How to use

npm install @samchon/openapi

import {
  OpenApi,
  SwaggerV2,
  OpenApiV3,
  OpenApiV3_1,
  IHttpMigrateApplication,
} from "@samchon/openapi";

// original Swagger/OpenAPI document
const input: 
  | SwaggerV2.IDocument
  | OpenApiV3.IDocument
  | OpenApiV3_1.IDocument
  | OpenApi.IDocument = { ... };

// you can convert it to emended OpenAPI v3.1
const output: OpenApi.IDocument = OpenApi.convert(input);

// it is possible to downgrade to Swagger v2 or OpenAPI v3
const v2: SwaggerV2 = OpenApi.downgrade(output, "2.0");
const v3: OpenApiV3 = OpenApi.downgrade(output, "3.0");

// you can utilize it like below
OpenApi.downgrade(OpenApi.convert(v2), "3.0");
OpenApi.downgrade(OpenApi.convert(v3), "2.0");

// also helps openapi generator libraries
const migrate: IHttpMigrateApplication = OpenApi.migrate(output);

Just install @samchon/openapi library and import OpenApi module from there.

Every features you need from @samchon/openapi are in the OpenApi module. If you want to connvert emended OpenAPI v3.1 type, just call OpenApi.convert() function with your document. Otherwise you want to downgrade from the OpenAPI v3.1 emended specification, call OpenApi.migrate() instead. Of course, if you combine both OpenApi.convert() and OpenApi.migrate() functions, you can transform every OpenAPI versions.

By the way, if you want to validate whether your OpenAPI document is following the standard specification or not, you can do it on the playground website. Click one of below links, and paste your OpenAPI URL address. Of course, if you wanna validate in your local machine, just install typia and write same code of playground.

• 💻 Type assertion
• 💻 Detailed validation

import { OpenApi, OpenApiV3, OpenApiV3_1, SwaggerV2 } from "@samchon/openapi";
import typia from "typia";
 
const main = async (): Promise<void> => {
  // GET YOUR OPENAPI DOCUMENT
  const response: Response = await fetch(
    "https://raw.githubusercontent.com/samchon/openapi/master/examples/v3.0/openai.json"
  );
  const document: any = await response.json();
 
  // TYPE VALIDATION
  const result = typia.validate<
    | OpenApiV3_1.IDocument
    | OpenApiV3.IDocument
    | SwaggerV2.IDocument
  >(document);
  if (result.success === false) {
    console.error(result.errors);
    return;
  }
 
  // CONVERT TO EMENDED
  const emended: OpenApi.IDocument = OpenApi.convert(document);
  console.info(emended);
};
main().catch(console.error);

Related Projects

• typia: https://github.com/samchon/typia
• nestia: https://github.com/samchon/nestia
• @wrtnio/openai-function-schema: https://github.com/wrtnio/openai-function-schema