easybill Invoicing

easybill is a German cloud invoicing / accounting tool (100% Made in Germany, 20,000+ customers) with a clean REST API at https://api.easybill.de/rest/v1.

Authentication

Generate an API key in easybill under Settings → App-Center / API (if you can't find it, contact easybill support to enable API access). Set it as EASYBILL_API_KEY. The connector sends it as Authorization: Bearer <key>. (easybill also accepts HTTP Basic Auth with email:apikey, but Bearer is simpler and is what this connector uses.)

Core concepts

• Customers (/customers) — your clients. Identified by numeric id and a human number.
• Documents (/documents) — the single resource for every document kind, discriminated by type: INVOICE, CREDIT, OFFER, REMINDER, DELIVERY, etc. Filter a list with type=INVOICE (comma-separated for several types). Each document carries an items array of line items.
• Positions (/positions) — your reusable product/article catalog (article number, description, unit price, VAT).

Pagination

List endpoints are page-based: page (default 1) and limit (default 100, max 1000). List responses wrap the rows in a documents/page/pages/total envelope.

Dates & filters

Date filters accept a single YYYY-MM-DD or a from,to range (e.g. document_date=2026-01-01,2026-03-31). paid_at=null returns unpaid invoices. Most ID filters accept comma-separated lists.

Tips

• To list only open invoices: easybill_list_documents with type=INVOICE and paid_at=null.
• Fetch a finished invoice as a PDF with easybill_get_document_pdf (returns the PDF base64-encoded in the pdf field).
• Amounts are in the document currency; VAT is per line item (vat_percent).