Image: compress request images

What it does

This transform re-encodes base64 images in user messages and optionally resizes them to max_edge_px. Smaller payloads upload faster and can reduce image token cost.

With skip_if_smaller on (the default), an image keeps its original bytes when compression does not shrink it.

Reference

Property	Value
Type ID	`image_compress_input`
Phase	`request`
Scopes	Provider, API key

When to use

Clients send large photos or screenshots and upstream requests hit size limits.
You want to cap image resolution for cost control.

Configuration

Option	Type	Required	Default	Description
`output_format`	string	No	`"original"`	`original`, `jpg`, `jpegxl_lossless`, `jpegxl`, `webp_lossless`, `webp`, or `png`.
`max_edge_px`	integer	No	—	Maximum width or height in pixels. Omit to keep the original dimensions.
`jpeg_quality`	integer	No	`80`	Quality 1-100 for JPEG output.
`jpegxl_quality`	integer	No	`90`	Quality 1-99 for lossy JPEG XL output.
`jpegxl_effort`	integer	No	`7`	JPEG XL encoding effort 1-10. Higher values compress more slowly.
`webp_quality`	integer	No	`80`	Quality 1-100 for lossy WebP output.
`skip_if_smaller`	boolean	No	`true`	Keep the original image when compression does not reduce the payload size.

Example rule

{
  "transform": "image_compress_input",
  "enabled": true,
  "phase": "request",
  "models": [
    "*"
  ],
  "config": {
    "output_format": "webp",
    "max_edge_px": 1568,
    "webp_quality": 80
  }
}

Set the environment variables MONOIZE_IMAGE_TRANSFORM_MAX_* to bound decode work. See Configuration.