Renders a letter as a PDF file in the fixed house layout (DIN 5008 address field, 25 mm writing margin, fold and punch marks, bold subject block). Pass content only, the layout is fixed. The signature image intentionally overlaps the closing line. Returns the absolute file path, the page count, layout metrics and warnings.

Renders the letter in memory and returns layout metrics and warnings without writing a file. Use it to check whether the address fits the address field or the letter runs onto a second page.

Cleans up a scanned signature: crops white borders, turns the paper background transparent and optionally recolours the ink. Writes a PNG that can be passed to create_letter as signature.path. Needs the optional sharp dependency.

Lists the sender profiles configured on this machine. Each profile carries the address and the signature of one person, so create_letter only needs the profile key.

Returns the millimetre geometry of the layout: address field, remark zone, writing margins, subject position, fold and punch marks.

Lists the supported languages together with their fixed texts (salutation, closing, enclosures, page numbering).

Lists the built-in font families and resolves a font name against the installed system fonts, so you can check what create_letter would embed.