dedupe_duration_s

Reuse an identical recent image without consuming additional image credits.

dedupe_duration_s is a non-negative integer that sets the deduplication lookback window in seconds for an HTML/CSS image or URL screenshot created with POST /v1/image. MCP-created HTML/CSS images and URL screenshots use the same behavior.

If your organization has an image with exactly the same content and parameters within that window, the API returns the existing image’s id and url instead of rendering a new image. The deduplicated request consumes no image credits.

The dedupe_duration_s value is not part of the identity comparison. It is also not saved on the image, so it affects only the request that includes it. You can choose a different lookback for every request.

Set the value to 0 to disable deduplication for a request.

URL screenshots default to 0 when the parameter is omitted. HTML/CSS images use a plan-specific default:

The explicit-value limits apply to both HTML/CSS images and URL screenshots.

{
  "html": "<h1>Monthly report</h1>",
  "css": "h1 { color: navy; }",
  "dedupe_duration_s": 3600
}

{
  "url": "https://example.com/report",
  "dedupe_duration_s": 300
}

{
  "html": "<h1>Always render a new image</h1>",
  "dedupe_duration_s": 0
}

The parameter applies to HTML/CSS images and URL screenshots created through the standard single-image POST endpoint or the MCP image-creation tools.

It does not apply to templated images, signed create-and-render URL images, or image batch requests. For more about exact matching and best-effort behavior, see the duplicate image detection guide.