BTW, you can signup and create a project with early access package for free. Then you will get access token to perform api requests for url to pdf and html to pdf.
You can also create templates. Which you can design using mustache (more templating engine coming soon). Then just pass context data to generate pdf via api.
Imagine you have build a mobile application or cloud function from which you want to create some sort of pdf. You can use templates to separate pdf design from you application code and just perform api requests to generate pdf. And if you want to modify your design, just change the template, your application code is untouched.
Thanks for your advice. Also, for now I have used bootstrap, ace editor, backend on django and the api backend in node js etc.
Your service looks awesome too.