> ## Documentation Index
> Fetch the complete documentation index at: https://docs.responsivevoice.org/llms.txt
> Use this file to discover all available pages before exploring further.

# CLI Tool

A command-line tool that synthesizes text to speech and saves audio to a file. Uses `@responsivevoice/api-client` directly — server-side only, no browser involvement.

> [!TIP]
> [Source code](https://github.com/responsivevoice/examples/tree/main/node/cli)

## Quick start

```bash
export RESPONSIVEVOICE_API_KEY="your-api-key"        # https://app.responsivevoice.org
export RESPONSIVEVOICE_API_SECRET="your-api-secret"  # "Server-to-server API secrets"
npm install
npm run cli -- "Hello, world!" --output hello.mp3
```

Unlike the browser examples, the CLI has no demo mode — the API client requires a valid key and secret to make HTTP requests to the synthesis endpoint. The `README` in the source tree lists every flag (`--voice`, `--rate`, `--pitch`, `--volume`, `--stdout`, `--list-voices`).

## Next Steps

- [HTTP Server](/examples/server) — REST wrapper around the same API client
- [REST API](/rest-api/) — direct HTTP usage
- [API Client Reference](/api/api-client/src) — full client documentation