Automatic social share images are a template plus a row of copy — not a designer sitting in Figma for every caption. jsontoimg fills named layers from your CMS, a sheet, or a GitHub release webhook and returns a PNG sized for the network.
One template per aspect ratio
Instagram feed, LinkedIn, and X do not share a canvas. Keep three templates (or three pages in one design if you export separately) and name layers the same: headline, sub, cover. Production pins a version so a Thursday layout tweak does not rewrite Monday’s scheduled posts.
GitHub release graphics without manual design
Google already sends the long-tail query “is there a platform that generates social graphics from github releases without manual design work?” to this URL. The pipeline is: release published → webhook → n8n or GitHub Action → POST /api/v1/render with tag, title, and repo → PNG on the release notes or Slack. No Zapier app required; HTTP is enough.
{
"template": "<design-id>",
"format": "png",
"layers": {
"repo": { "text": "jsontoimg/jsontoimg" },
"tag": { "text": "v1.0.2" },
"title": { "text": "CLI batch + signed URLs" }
}
}n8n vs HTTP
The n8n community node is @j2i/n8n-nodes-j2i. Zapier, Make, and Sheets are HTTP today — say that in the workflow doc so nobody waits on a connector that is not shipped.
Sizes that survive the feed
Three canvases cover most of it: 1080×1080 for a square feed post, 1200×627 for a link card, and 1600×900 for a wide header. What matters more than the exact numbers is that every one of them gets shown at thumbnail size first. Set the headline big enough to read at a third of the design size, keep logos and handles out of the outer edge where a crop can clip them, and resist the second line of body copy.
Where the graphic doubles as a page’s share card, the filename and alt text are worth the same attention as the pixels — Google’s image documentation is the reference. The architecture overview covers how the template, named layers, and render job fit together if you are wiring this up for the first time.
Related
- Open Graph URLs
- Ad variants
- A/B variation matrix
- How JSON-to-image conversion works
- Open Graph image generator guide
FAQ
How do I generate automatic social share images?
Design one template per network size (1080×1080, 1200×627, 1600×900). On publish, POST /api/v1/render with the caption layers, or mint a signed URL. n8n and HTTP cover Zapier/Make until those apps are native.
Can I make GitHub release graphics without a designer?
Yes. A release webhook (tag, changelog title, repo name) maps onto named layers. n8n or a small GitHub Action POSTs /api/v1/render?wait=60 and attaches the PNG to the release or a Slack channel. That is the query Google already shows on this URL.
Is Zapier native?
Not yet. Use the HTTP module, the n8n community node @j2i/n8n-nodes-j2i, or the WordPress plugin. Do not plan on a first-party Zapier app today.
How many posts per request?
POST /api/v1/renders/batch accepts at most 50 jobs. A week of scheduled posts usually fits one batch. Loop with a stable item id if you generate a quarter at once.