Image collage

Image collage is an API that combines several photos into one, in a grid (contact-sheet style). Each image is fitted inside its cell without cropping or distorting it.

How it works

You send an array of images (2 to 30) and get back one image with all of them arranged in a grid. The number of columns is calculated automatically (as close to square as possible) if you don't set it.

All you need

Your API key. Create it in your dashboard with "+ Create key".
In your automation platform, an "HTTP Request" step (n8n, Make, Zapier, Pipedream…).

How to use it in n8n

Method: POST · URL: https://api.cofferdock.com/image-collage
Send Headers: x-api-key = your key, Content-Type = application/json
Send Body (JSON): { "images": ["<base64 1>", "<base64 2>", "<base64 3>"] }
In Options → Response → Response Format: choose File

Options

Option	Default	What it does
`images`	-	Required. Array of 2 to 30 base64 images.
`columns`	automatic	How many columns.
`cell_width`, `cell_height`	`400`	Each cell's size in pixels.
`gap`	`10`	Spacing in pixels between images and at the edge.
`background`	`#ffffff`	Background color in cells and gaps.

API overview

Endpoint: POST https://api.cofferdock.com/image-collage
Auth: x-api-key: YOUR_KEY.
Input: JSON ONLY (several binaries can't travel raw in one body).
Engine: sharp. Each image is fitted with fit: inside (never crops) and centered in its cell.
Limits: 30 requests/min per IP. Final canvas up to 60 megapixels. 1 call = 1 credit, no matter how many images.

Example

curl -X POST "https://api.cofferdock.com/image-collage" \
  -H "x-api-key: YOUR_KEY" -H "Content-Type: application/json" \
  -d '{"images":["...","...","..."],"columns":3}' \
  --output collage.png

Response

{ "success": true, "image": "iVBORw0KGgo...", "mime_type": "image/png",
    "meta": { "count": 3, "columns": 3, "rows": 1, "width": 1230, "height": 420,
    "size_bytes": 84213, "used": 12, "remaining": 488 } }

What you get back

By default (JSON): image as base64. Add output=image for the raw binary, or output=url for a temporary link.