uigen serve

The serve command reads an API spec and starts a local server with a fully generated UI.

Usage

uigen serve <spec> [options]
npx @uigen-dev/cli serve <spec> [options]

<spec> can be a local file path or a remote URL.

Options

Flag	Type	Default	Description
`--port`	`number`	`4400`	Port to listen on
`--proxy-base`	`string`	From spec `servers[0].url`	Override the API proxy target URL
`--renderer`	`string`	`react`	Renderer to use (`react`; `vue` and `svelte` are planned)
`--verbose`	`boolean`	`false`	Log detailed proxy request/response information

Examples

Local file

uigen serve ./openapi.yaml

Remote URL

uigen serve https://petstore3.swagger.io/api/v3/openapi.json

Custom port

uigen serve ./openapi.yaml --port 8080

Custom proxy base

Override the API target when it differs from the spec's servers field:

uigen serve ./openapi.yaml --proxy-base http://localhost:3001

Verbose proxy logging

uigen serve ./openapi.yaml --verbose

With --verbose, the CLI logs each proxied request and response:

→ GET /api/users
← GET /api/users 200 (42ms)
  [Auth] Bearer token

Serving modes

The CLI operates in two modes depending on how it was installed:

Dev mode

Used when running from the monorepo (no pre-built renderer in node_modules). Starts a Vite dev server with hot module replacement.

Static mode

Used when installed via npm or npx. Serves the pre-built dist/ directory with a plain Node.js HTTP server. Vite is not required at runtime.

Both modes expose the same URL and behaviour.

Renderer support

Currently only react is available. vue and svelte renderers are planned for a future release. Passing an unknown renderer value falls back to react with a warning.

Notes

The spec file is read once at startup. Changes to the spec require restarting the server.
The proxy forwards all requests to /api/* to the target server.
Authentication headers are injected by the proxy transparently (your API never sees UIGen-specific headers).