Hylen Invoice

Use Hylen Invoice from ChatGPT, Claude or any AI assistant

Ask your assistant to “invoice Acme for 500 dollars of design work” and it drafts the invoice in Hylen, shows it to you, and gives you a link that opens it in the editor. There you sign in and download it free. Hylen works with any assistant that supports custom connectors through the Model Context Protocol (MCP).

Connector URL

https://hyleninvoice.com/mcp

Your assistant asks you to sign in to Hylen and approve it the first time. For questions about Hylen and totals only, with no sign-in, use https://hyleninvoice.com/mcp/public.

How to connect it

  1. In Claude, open the settings for connectors and add a custom connector. In ChatGPT, open the settings for apps or connectors and add a new one. Other assistants call this adding an MCP server.
  2. Give it a name, such as Hylen Invoice, and paste the connector URL above. There is no key or secret to enter.
  3. When your assistant opens Hylen, sign in with your email and choose Approve. The approval page lists what the assistant is asking to do.
  4. Ask it for an invoice.

The exact menu names differ between assistants and change from time to time. If you cannot find the setting, search your assistant’s help for “custom connector” or “MCP”.

What an assistant can do

  • Draft invoices and other documents from what you tell it, and change the drafts it made.
  • Show you a preview. The preview is a low resolution image of the first page, marked as a preview.
  • Give you a link that opens a draft in the editor, so you can check or finish it, then sign in and download it yourself. Downloading is free.
  • List the invoices you have issued, and mark them as paid, pending or cancelled.
  • Tell you which account it is connected to, and whether a plan you bought earlier is still running.

When you approve an assistant, you are asked to allow some or all of these:

  • See the drafts it created for you, and preview them.
  • Create and edit invoice drafts for you.
  • See the invoices you have issued.
  • Mark your issued invoices as paid, pending or cancelled.
  • See your email address and plan.

What an assistant can never do

  • Download the finished PDF through Hylen’s assistant tools. No tool returns it: you download it yourself in your browser, signed in to Hylen, exactly as you do when you use the editor on your own.
  • Pay for anything, or start, change or cancel a plan.
  • Sign in for you, or send you a sign-in email.
  • See, reveal or email a retrieval code.
  • Change your email address or delete your account.

These are not settings. There is no permission for them, so no assistant can be given them.

Stopping an assistant

You can see every assistant you have approved, and disconnect any of them, under Connected apps on your account page. Disconnecting takes effect at once. Signing out of Hylen does not disconnect an assistant.

What we keep about connected apps, and for how long, is in the privacy policy. Hylen is free; the terms say what happens to plans and purchases made before it was.