Quick Start

This guide generates your first runnable request example and discovers the available generators.

1. Install

npm install @powerduck/openapi-codegen

2. Generate from a document

Pass a parsed OpenAPI document plus the target path, method, language, and client. generate() returns the source code as a string.

import { generate } from "@powerduck/openapi-codegen";
import document from "./openapi.json" with { type: "json" };

const code = generate({
  document,
  path: "/pets/{id}",
  method: "get",
  language: "javascript",
  client: "fetch",
});

console.log(code);

CommonJS equivalent:

const { generate } = require("@powerduck/openapi-codegen");
const fs = require("node:fs");

const document = JSON.parse(fs.readFileSync("./openapi.json", "utf8"));

const code = generate({
  document,
  path: "/pets",
  method: "post",
  language: "python",
  client: "requests",
});

console.log(code);

3. List available generators

list() returns every registered generator descriptor:

import { list } from "@powerduck/openapi-codegen";

for (const { language, client } of list()) {
  console.log(`${language}/${client}`);
}

Each descriptor is { language: string; client: string }. The identifiers are case-sensitive; use them exactly as shown in the API reference generator list.

You can select one programmatically:

import { generate, list } from "@powerduck/openapi-codegen";

const picked = list().find(
  (g) => g.language === "javascript" && g.client === "fetch",
);

if (!picked) throw new Error("Generator not available");

const code = generate({
  document,
  path: "/pets",
  method: "get",
  language: picked.language,
  client: picked.client,
});

4. Provide credentials

Use securityValues to fill in named security schemes. Keys must match the security scheme names in the document:

const code = generate({
  document,
  path: "/pets/{id}",
  method: "get",
  language: "javascript",
  client: "fetch",
  securityValues: {
    bearerAuth: "YOUR_ACCESS_TOKEN",
    apiKey: "YOUR_API_KEY",
  },
});

5. Override the server URL

const code = generate({
  document,
  path: "/pets",
  method: "get",
  language: "shell",
  client: "curl",
  serverUrl: "https://staging.example.com/v1",
});

Error handling

generate() throws for missing input or unsupported generators. Wrap calls when processing untrusted documents:

try {
  const code = generate({
    document,
    path: "/pets/{id}",
    method: "get",
    language: "javascript",
    client: "fetch",
  });
  console.log(code);
} catch (error) {
  console.error("Generation failed:", error instanceof Error ? error.message : error);
}

What's next?

• Configuration — GenerateOptions, RequestIR, Generator, Plugin.
• Examples — JavaScript fetch, Python requests, cURL, custom generator, plugin, direct RequestIR.
• API Reference — every export.