Invoices, reports, posts, and ads, made for you in your brand.
Document generation software makes a PDF or an image from a saved design and new data. With thirds.ai, your AI assistant does the whole job. Connect ChatGPT or Claude, pick a designer-made invoice, report, post, or ad from the gallery, and put your brand on it once. From then on you just ask for each new file, and the assistant writes the content and hands you the finished PDF or image. Need the same design in every size, in every language, or for a whole spreadsheet of clients? It makes them all at once, and your automations keep making files while nobody is at the screen.
Free to start. No card needed.
Every picture here is a real file made with thirds.ai. Click View HTML on any of them to see the code behind it.
Design studio invoicePDF · A4 Knitwear launch storyImage · 1080 × 1920 Monthly KPI reportPDF · A4 Creator video thumbnailImage · 1280 × 720 Course completion certificatePDF · A4 landscape Business coach bannerImage · 1584 × 396 Festival day passPDF · 794 × 374 Bistro evening menuPDF · A4
How it works
How document generation works in thirds.ai
Setup takes a couple of minutes, and your assistant can walk you through it. Start with the file your business sends most, such as the invoice or the weekly sale post. If you would rather click than chat, the studio editor does every step too.
Connect your AI assistant
Connect thirds.ai to ChatGPT, Claude, Gemini, Grok, or any other AI that supports MCP. If you like, ask it to set up your brand from your logo and colours, so every file comes out in your brand from the first one.
Ask for a template
Ask for a template for the thing you need, and change it until you like it. The assistant can start from a designer-made gallery template, build one from a sentence, or rebuild any image you upload as an editable template in your brand.
Ask for each new file
From then on, ask for the invoice, the post, or the report, and the assistant writes the content and hands you the finished PDF or image. Ask for every size at once, every language, or a whole spreadsheet of files in one go.
Try it here. Put your own brand on this sale sticker, then change the offer or the code.
PDF documents
Send invoices, statements, and reports that look designer-made, without touching them.
Invoices, account statements, and client reports come out as pixel-perfect PDFs in your brand. Your accounting tool or billing service sends the numbers through Zapier, Make, or n8n or the API, so the month's statements go out while nobody is at the screen, and a client with forty lines gets a PDF as neat as a client with four. The invoices and reports pages show each job from start to finish.
- Your logo, colours, and fonts on every page, from one brand kit.
- A whole spreadsheet of clients in one batch.
- One PDF can have up to 100 pages.
Static images
Launch a campaign in every size and language without redoing the design.
Ask your assistant for the square post, the story, and the wide banner from one design, and smart resize fits the layout to each size. Ask for the same post in French and German, and it writes the text and keeps the design, with long lines shrinking to fit. The social images and static ads pages show each job from start to finish.
- Every size from one design, and adding a size is free.
- Every language your assistant writes.
- Download a PNG, JPEG, or WebP.
Use cases
Designer-made templates for every file you send.
Designers made every template in the gallery, so a good result takes no design work on your side. Pick one and put your brand on it in one step, and your assistant, your automations, and the editor all make files from it. These four give you a taste of the range.
Client invoicePDF · A4 Line items, tax, and totals in a PDF your billing tool can send for you.
Seasonal offerImage · 1200 × 1200 An offer, a price, and a next step, ready for every size your campaign runs in.
Monthly reportPDF · A4 Fresh figures, highlights, and next steps, written and filled in by your assistant each month.
Sale price adImage · 1080 × 1080 The old price struck through and the new price large, for every offer you run.
For developers and agents
Make any file with one request from your code.
Keeping your own PDF and image layout code alive takes time you'd rather spend on your product. Send a template ID and the data for one file, and the API returns the PDF or image, with no browser to run on your side. Connect the MCP server, and ChatGPT, Claude, Cursor, or your own agent makes files from the same templates your team edits in the browser. Zapier, Make, and n8n work too, and webhooks tell your app when a file is ready.
curl --fail-with-body --silent --show-error \
https://thirds.ai/v1/pdf \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: report-2026-09-fieldnote" \
--data '{
"template_id": "tpl_YOUR_TEMPLATE",
"version": 1,
"data": {"client": "Fieldnote Labs", "period": "September 2026"}
}'{
"servers": {
"thirds": {
"type": "http",
"url": "https://thirds.ai/mcp",
"headers": {
"Authorization": "Bearer YOUR_API_KEY"
}
}
}
}What to expect
What it costs and what the limits are.
You pay 1 credit for each PDF or image that comes out, and nothing for one that fails. Paid plans keep your files for a year, and the Free plan keeps them for 30 days.
- One finished file
- One credit for a PDF, PNG, JPEG, or WebP
- Failed files
- Free
- PDF limits
- Up to 100 pages and 25 MiB
- Image limits
- Up to 32 million pixels and 25 MiB
- Files kept
- Up to a year on paid plans, 30 days on Free
Paid plans start at $29 a month.
Choose your file
Start with the file your business sends most.
Each page below shows real templates and the steps for one kind of file. Pick the one you send most, and the rest follow from the same account.
Billing
Invoices, quotes, and receipts in your brand, with the numbers sent by your accounting tool or your assistant.
Reports and documents
Client and team reports that go out every week or month, certificates, flyers, and any other HTML that needs to become a real PDF.
Marketing images
Posts, stories, ads, and TikTok slideshows in every size and language from one design.
Questions people ask before they start
Make a sample imageWhat is document generation software?
Document generation software makes a PDF or an image from a saved design and new data. You set up the layout once, then send the name, the prices, or the photo for each copy. With thirds.ai, the part that sends the data can be you, your AI assistant, or your own automations, and you get a PDF or a PNG, JPEG, or WebP image in your brand each time.
Why use thirds.ai instead of a design tool or an AI image generator?
A design tool leaves you editing every new file by hand. An AI image generator changes the layout, the fonts, and where the text sits on every try, and gives you one picture you can't edit. thirds.ai keeps a designer-made template in your brand, and your assistant or your automations make every file from it: every size, every language, or a whole spreadsheet at once, with nobody at the screen.
Can my AI assistant or agent make the files?
Yes. Connect thirds.ai to ChatGPT, Claude, Gemini, Grok, Cursor, or another AI tool that supports MCP. Your assistant then builds the design with you, writes the content, and makes files from the same templates your team edits in the browser. Set up ChatGPT. Set up Claude. Set up Gemini. Set up Grok.
Can I use one account for invoices, reports, social images, and ads?
Yes. Every plan makes both PDFs and images, and includes the editor, the template gallery, and the AI assistant connection. Save a design for each kind of file and make every file from the same account.
Do I need to write code to make files from a template?
No. Ask ChatGPT or Claude for the file, or copy a gallery template and change it in the editor. Code, Zapier, Make, and n8n are there for when you want files made without anyone at the screen.
Can I try a template before I buy credits?
Yes. In the playground you can change a template and watch the preview update with no account. Click Download free to sign in and get a clean file. A verified free account gets 50 credits each month for PDFs and images. An AI build costs 50 credits, and your free monthly credits can pay for it.
How long do you keep my files?
We keep each finished file for up to a year on paid plans and 30 days on Free. A free file from a free tool stays for one hour.
PDF and image use cases
Make your next invoice or post in your brand.
Pick a template for the file you send most, put your brand on it, and have your first PDF or image a few minutes from now. After that, ask your assistant for each new one, or let your automations make them while you do something else.