CLI

The openapi-ng binary exposes two top-level commands: generate and init.

openapi-ng generate

openapi-ng generate --input <path> [options]

Flag	Short	Description
--input <path>	-i	Path to an OpenAPI 3.x JSON or YAML file, or an https:// URL (required). See URL inputs below.
--output <dir>	-o	Output directory. Omit to generate in memory without writing files
--emit <targets>		Comma-separated emit list: models,angular (repeatable). Default: models,angular. 'angular' auto-includes 'models'.
--verbose		Print warning diagnostics with codes
--mapped-type <spec>		Replace a schema with an external type import (repeatable). Format: schema:import:type[:alias] — see Mapped types.
--config <path>	-c	Path to a config file (overrides auto-discovery — see Configuration)

URL inputs

--input (and the input config key, and generate({ inputPath })) accept an https:// URL alongside local file paths:

openapi-ng generate -i https://example.com/openapi.yaml -o ./src/generated

Only https:// is supported — http:// and other schemes are rejected. Redirects are followed up to 5 hops and must stay on https://. The fetched body counts against the same input cap that applies to local files (OPENAPI_NG_MAX_INPUT_BYTES, default 16 MiB). The fetch wall-clock timeout defaults to 30 s and is configurable via OPENAPI_NG_INPUT_TIMEOUT_MS. See Environment variables for both knobs.

openapi-ng init

openapi-ng init [--format yaml|json|ts|js]

Writes a starter config file in the current directory. Default format is yaml. --format ts writes openapi-ng.config.mts (with a defineConfig import and a commented naming.parse RegExp example); --format js writes openapi-ng.config.mjs. Both pick the .m* extension on purpose: it forces ESM, avoiding Node’s CJS-first parse

• ESM-reparse penalty under a typeless package.json, and keeps the config independent of package.json#type mutations.

Aborts (no overwrite) if any of the eight discoverable config files already exists in the current directory.