This is a real render from the API with the example values below, at 1200×630.
For Substack, Ghost, Beehiiv and self-hosted newsletters: the masthead with double rules and the dateline make every issue look like an edition of the same publication. Light paper by default, dark ink with theme: dark.
Fields
Every field is optional. Long text shrinks to fit instead of overflowing; an image field takes a public URL that we fetch on our side.
| Field | Type | Description | Example |
|---|---|---|---|
title |
text | Headline of this issue. default: Issue headline | The quiet death of the landing page |
newsletter |
text | Newsletter name for the masthead. default: The Newsletter | The Growth Ledger |
issue |
text | Issue label, e.g. Issue No. 87. | Issue No. 87 |
date |
text | Date as you want it printed. | October 22, 2026 |
excerpt |
text | One-sentence teaser under the headline. | Why the best SaaS teams now ship docs, changelogs and templates instead. |
author |
text | Byline, e.g. By Maya Chen. | By Maya Chen |
site |
text | Your domain or a short URL. | growthledger.news |
accent |
colour | Brand colour as hex, e.g. #6366f1. Drives buttons, highlights and the background glow. default: #b91c1c | #b91c1c |
theme |
dark | light | Colour scheme: dark or light. default: light | — |
Render it with one request
Use the slug as template. The response holds the URL of the finished PNG; ?wait=true keeps the connection open until it is ready.
curl -X POST "https://imageapi.benchkithq.com/v1/images?wait=true" \
-H "Authorization: Bearer sk_live_YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{
"template": "newsletter-issue",
"modifications": {
"title": "The quiet death of the landing page",
"newsletter": "The Growth Ledger",
"issue": "Issue No. 87",
"date": "October 22, 2026",
"excerpt": "Why the best SaaS teams now ship docs, changelogs and templates instead.",
"author": "By Maya Chen",
"site": "growthledger.news"
}
}'Or paste a signed URL into og:image
For static sites, Webflow, Shopify and no-code tools: put the fields in the query string and sign it with your signing secret. The first request renders the image, every later one is a redirect to the cached file. How to compute the signature.
<meta property="og:image" content="https://imageapi.benchkithq.com/i/acc_YOUR_ACCOUNT_ID/newsletter-issue.png?author=By%20Maya%20Chen&date=October%2022%2C%202026&excerpt=Why%20the%20best%20SaaS%20teams%20now%20ship%20docs%2C%20changelogs%20and%20templates%20instead.&issue=Issue%20No.%2087&newsletter=The%20Growth%20Ledger&site=growthledger.news&title=The%20quiet%20death%20of%20the%20landing%20page&s=YOUR_SIGNATURE">Make it yours
accent and theme change per request. For anything more, copy the template into your account: you get an ordinary HTML template with the same fields that you can edit in the dashboard or through the API. If the slug is free on your account, the copy takes it — your integrations switch to your version without changing a line.
curl -X POST "https://imageapi.benchkithq.com/v1/templates/library/newsletter-issue/copy" \
-H "Authorization: Bearer sk_live_YOUR_KEY"More OG image templates
Blog post
Job posting
Event
Podcast episode
Changelog / release
Documentation page
Real estate listing
Product card
Product on sale
Course lesson
Recipe
Video thumbnail
Quote card
Case study / testimonial
GitHub repository
Feature announcement
Profile / author card
Comparison (A vs B)
Stat highlight