Render one branded PDF in a brand kit and save it to the user's files: any document the user describes, from an invoice or a statement to a one-pager, a proposal, a memo, a case study, an agenda or a report. Drafts are limited to 20 per day. Templates: 'invoice' takes items of description, quantity, unit_price, up to 30 plus props invoice_number, issued_on, due_on, bill_to, currency, tax_rate, notes; 'statement' takes items of description, date, amount, up to 30 plus props account, account_of, period_start, period_end, currency, opening_balance, notes; 'report' takes markdown or blocks plus props subtitle, author, dated; 'letter' takes markdown or blocks plus props recipient, dated, signoff; 'proposal' takes markdown or blocks plus props client, valid_until, prepared_by. A document template renders whatever markdown you give it, so an unfamiliar ask (a press release, a checklist, a brief) is still a report, letter or proposal with the right headings. Line item fields are all strings, and every date is YYYY-MM-DD. Write a document as markdown (headings, lists, tables) or as blocks, never both, and its first heading becomes the title unless you pass a title. Leave brand_kit_id out to use the space's default brand. Returns the artifact id and how many pages it came to. It costs 1 credit, or nothing on a Solo or Pro plan. Do not call this again to retry.