Business letters
Letterhead letter
Write a business letter on a letterhead with a logo, an address block, and a signature line.
Use this for proposals, notices, and formal replies.
TypeDocuments
File typesPDF
SourceMade by thirds.ai with original graphic marks and fictional sample names.
LicenceFree to copy and use in your own templates
Your data
See the fields before you copy.
Your copy starts with these sample values. Change any of them.
{
"company_name": "Quill & Co.",
"company_tagline": "Writing and editing for business",
"company_address": "8 Ink Lane, Dunedin",
"company_phone": "+64 3 555 0142",
"company_email": "office@quill.example",
"date": "2026-09-06",
"recipient_name": "Ms Priya Raman",
"recipient_title": "Finance lead, Harbour Kitchen Supply",
"recipient_address": "40 Wharf Lane, Wellington",
"subject": "Our proposal for the 2027 product catalogue",
"greeting": "Dear Ms Raman,",
"paragraph_1": "Thank you for meeting us last week. We enjoyed hearing about the plans for the 2027 catalogue, and we are pleased to send our proposal for the writing and editing work.",
"paragraph_2": "We will write all 120 product descriptions, edit the buyer guide, and proofread the final layout. Our team can begin on 1 October and deliver the final text by 20 November. The full price is set out in the attached quote.",
"paragraph_3": "Please let us know if you would like any changes. We are happy to talk through the plan on a call at a time that suits you.",
"closing": "Kind regards,",
"signer_name": "Hugo Whitfield",
"signer_title": "Director, Quill & Co.",
"footer": "Quill & Co. Ltd is registered in New Zealand. Company number 5590 112."
}Use it your way
Render the same template on the web, by API, or through MCP.
curl https://thirds.ai/v1/pdf \
-H "Authorization: Bearer $THIRDS_API_KEY" \
-H "Content-Type: application/json" \
-d '{"template_id":"tpl_your_copy","version":1,"data":{"company_name":"Quill & Co.","company_tagline":"Writing and editing for business","company_address":"8 Ink Lane, Dunedin","company_phone":"+64 3 555 0142","company_email":"office@quill.example","date":"2026-09-06","recipient_name":"Ms Priya Raman","recipient_title":"Finance lead, Harbour Kitchen Supply","recipient_address":"40 Wharf Lane, Wellington","subject":"Our proposal for the 2027 product catalogue","greeting":"Dear Ms Raman,","paragraph_1":"Thank you for meeting us last week. We enjoyed hearing about the plans for the 2027 catalogue, and we are pleased to send our proposal for the writing and editing work.","paragraph_2":"We will write all 120 product descriptions, edit the buyer guide, and proofread the final layout. Our team can begin on 1 October and deliver the final text by 20 November. The full price is set out in the attached quote.","paragraph_3":"Please let us know if you would like any changes. We are happy to talk through the plan on a call at a time that suits you.","closing":"Kind regards,","signer_name":"Hugo Whitfield","signer_title":"Director, Quill & Co.","footer":"Quill & Co. Ltd is registered in New Zealand. Company number 5590 112."}}'{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "render",
"arguments": {
"output": "pdf",
"idempotency_key": "letterhead-letter-1",
"request": {
"template_id": "tpl_your_copy",
"version": 1,
"data": {
"company_name": "Quill & Co.",
"company_tagline": "Writing and editing for business",
"company_address": "8 Ink Lane, Dunedin",
"company_phone": "+64 3 555 0142",
"company_email": "office@quill.example",
"date": "2026-09-06",
"recipient_name": "Ms Priya Raman",
"recipient_title": "Finance lead, Harbour Kitchen Supply",
"recipient_address": "40 Wharf Lane, Wellington",
"subject": "Our proposal for the 2027 product catalogue",
"greeting": "Dear Ms Raman,",
"paragraph_1": "Thank you for meeting us last week. We enjoyed hearing about the plans for the 2027 catalogue, and we are pleased to send our proposal for the writing and editing work.",
"paragraph_2": "We will write all 120 product descriptions, edit the buyer guide, and proofread the final layout. Our team can begin on 1 October and deliver the final text by 20 November. The full price is set out in the attached quote.",
"paragraph_3": "Please let us know if you would like any changes. We are happy to talk through the plan on a call at a time that suits you.",
"closing": "Kind regards,",
"signer_name": "Hugo Whitfield",
"signer_title": "Director, Quill & Co.",
"footer": "Quill & Co. Ltd is registered in New Zealand. Company number 5590 112."
}
}
}
}
}