# AI Invoice Generator by Alder

> A free AI invoice generator: make invoices from ChatGPT, Claude or any AI agent, or on the web, and download them as PDFs. No signup, no account, no invoice limit. Made by Alder (https://meetalder.com), which builds AI agents for accounts receivable.

Money is integer minor units (cents): 12.50 USD is 1250. Dates are YYYY-MM-DD. Currencies: usd, cad, eur, gbp, aud, nzd. Tax applies after the discount and not to shipping.

## For agents

- MCP (Streamable HTTP, stateless, no authentication): https://alderinvoices.com/mcp
  - claude.ai, ChatGPT or Claude Desktop: add https://alderinvoices.com/mcp as a custom connector.
  - Claude Code: `claude mcp add --transport http alder-invoices https://alderinvoices.com/mcp`
  - Tool: draft_invoice. It prices the invoice (subtotal, discount, tax, shipping, total) and returns builderUrl, a link that opens the invoice filled in, ready to review and download as a PDF.
- REST: OpenAPI 3.1 spec at https://alderinvoices.com/openapi.json
  - `POST /api/v1/drafts` (no key): totals + the prefilled builder link

## Things to know

- Nothing is stored or emailed. The invoice lives in the link until the user downloads it.
- Give the user builderUrl; they can add their business details, a due date and notes there.

## Pages

- [Invoice builder](https://alderinvoices.com/create): make an invoice, download a PDF, no signup
- [Developers](https://alderinvoices.com/developers): MCP setup and the drafts API