A NodeJS client the NuGet feed API.
import { NuGetClient, createClient } from 'nuget-client';
const client = createClient('https://api.nuget.org/v3/index.json');
const suggestedPackageIds = await client.suggestPackageId('Newtonsoft');
const availablePackageVersions = await client.getAvailablePackageVersions('Newtonsoft.Json');
The NuGet API is slow; caching results is probably a good bet.