LMNT Node module

Overview

A Node.js module to provide convenient access to the LMNT API from applications written in Javascript.

For more on the LMNT API, see the documentation.

Usage

Create a Speech instance passing your API key to the constructor, and call any of the available API methods.

To obtain an API key, visit the LMNT Account page.

Sample code:

import Speech from 'lmnt-node';

// You can set the `LMNT_API_KEY` environment variable instead of passing in a string below.
const speech = new Speech('your-api-key-here');

// Fetch the list of available voices.
const voices = await speech.fetchVoices();
console.log(voices);

// Synthesize text to audio.
const synthesis = await speech.synthesize('Hello World.', 'lily', { format: 'mp3' });
console.log(synthesis.audio);

See the simple demo apps for more examples.

Next.js and Edge Runtime

This SDK is compatible with Next.js and the Edge Runtime. To use it in a Next.js project, you will need to add the following to your next.config.js file:

webpack: (config, { isServer }) => {
    // Only run this on the server
    if (isServer) {
      config.resolve.fallback = config.resolve.fallback || {};
      config.resolve.fallback.fs = false;
    }

    return config;
  },

The createVoice() method uses the fs module, which is not available in the Edge Runtime. While the SDK automatically disables this method in non-Node.js environments, this code snippet will prevent the build from failing when the fs module is not available.

Learn more about custom webpack configuration in Next.js here.

Release History

1.2.3 / Aug 1, 2024

• add conversational option to streaming and non-streaming synthesis

1.2.1 / July 16, 2024

• add language option to streaming synthesis

1.2.0 / May 15, 2024

• add optional sample_rate and language parameters in synthesize
• add optional baseUrl parameter to Speech constructor
• fix incorrect type definitions for synthesis response

1.1.2 / Feb 15, 2024

• enable client-specified format and sample_rate in streaming connection
• read LMNT_API_KEY from environment if not explicitly specified

1.1.1 / Feb 14, 2024

• support CommonJS modules in addition to ES modules
• expose more types to TypeScript for better tooling support

1.1.0 / Jan 5, 2024

• synthesizeStreaming will now return a buffer_empty boolean when extras are requested. This can be used to determine when the server has no more audio to send after the client has sent a flush message.

1.0.0 / Nov 16, 2023

• Breaking changes - Please update your code to use the new behavior or pin to a previous version if preferred:
  • Default audio encoding format in synthesize is now mp3 (previously wav). Format can be specified by adding the format='wav' or format='mp3' option to the synthesize call.
  • fetchVoices now returns a list of voice dictionaries for simplicity of return values and ease of use. Previously it returned a dictionary with key voices which contained a dictionary of voice dictionaries keyed by their voice id.
  • synthesize no longer returns just the binary audio data. It instead always returns a dictionary with keys audio, durations (optional), and seed (optional).
• Features:
  • Add ability to filter by starred and owner in fetchVoices.
  • Add ability to return durations and seed from synthesize.
  • Add fetchVoice method to fetch a single voice.
  • Add createVoice method to create a new voice.
  • Add updateVoice method to update an existing voice, including starring voices.
  • Add deleteVoice method to delete an existing voice.
  • Add synthesizeStreaming method to support full-duplex synthesis streaming.
  • Add fetchAccount method to fetch account information.

0.0.2 / Sep 20, 2023

• Features:
  • Add optional length parameter specifying target speech duration.
  • Make streaming work with the Edge runtime.
  • Add TypeScript type definitions.
  • Add close method to StreamingSynthesisConnection class allowing explicit cleanup if desired.
• Bug fixes:
  • End the streaming async iterator when the synthesis is finished.
  • Fix demo link in README.

0.0.1 / Sep 6, 2023

• Initial release.