---
title: "OG image API: dynamic share images from a signed URL | Bannx"
description: "Put a signed image URL in your og:image tag. It renders your template on first open and comes from cache after. No key in the link. PNG or WebP."
source: https://bannx.com/products/og-image-api
---

# Give every page its own share image, from a URL.

Sign a link with the page's title and put it in your og:image tag. It renders your template the first time it is opened and comes from cache after that.

[Try a template free](https://bannx.com/templates/blog-post-og-card)[Read about signed URLs](https://bannx.com/docs/rendering#signed-image-urls)

No account · PNG and PDF downloads · No watermark

*Nine cards from three campaigns in English, French and Spanish: linked as signed image URLs in each page's og:image tag, each rendered on first open, then re-sized into a landscape ad, a story and a banner.*

posts → share imagesURL

## How it works

1. ### Design the card
   Start from a share-card template or design your own at 1200 × 630. Mark the title, author and image as variables, then publish.
2. ### Sign the links
   Sign one URL per page with its values, up to 500 in one request, or sign them in your own code with your space's secret. Signing is free.
3. ### Put it in the tag
   Use the URL as your og:image. The first open renders it and every open after comes from cache, so a page shared a thousand times renders once.

## Where it helps

- [Blog share cardsA card with each post's title and author.](https://bannx.com/templates/blog-post-og-card)
- [Images in emailsA personal image per recipient, merged into the link by your email tool.](https://bannx.com/docs/rendering#signing-offline)
- [Links made by agentsYour AI agent signs the same URLs over MCP.](https://bannx.com/docs/integrations/mcp)

## What it costs

25 free renders every month. Starter is $15 a month for 1,000 credits. An image costs 1 credit, a video clip 5 credits.

Each distinct URL renders once, for 1 credit, on its first open. Opens after that come from cache and cost nothing. Signing is free.

[See all plans](https://bannx.com/pricing)

## Questions

Something else on your mind? Email [[email protected]](https://bannx.com/cdn-cgi/l/email-protection#781b17160c191b0c381a19161600561b1715).

Is there an API key in the URL?

No. The link carries a signature instead. Anyone can open it, but changing a value in it breaks the signature, so nobody can make your template say something else.

What does each URL cost?

Which formats and sizes?

Can a link expire?

Can I try it without an account?

## One template, a share image for every page.

Try a template free, or read how signed URLs work.

[Try a template free](https://bannx.com/templates/blog-post-og-card)