POST /upload

Uploads a file and returns a persistent ID that can be used as an input reference anywhere in the API. Files can be uploaded once and referenced in any number of requests.

POST https://api.rivermark.ai/upload

Uploading a file

Send the file as multipart/form-data:

const form = new FormData();
form.append("file", new Blob([await fs.readFile("hero.png")], { type: "image/png" }), "hero.png");

const file = await fetch("https://api.rivermark.ai/upload", {
  method: "POST",
  headers: { Authorization: `Bearer ${process.env.RIVERMARK_API_KEY}` },
  body: form,
}).then((r) => r.json());

{
  "id": "rmf_cj4hbqz9x0001v2x8n6tqz7e",
  "name": "hero.png",
  "mime_type": "image/png",
  "size": 842113,
  "kind": "image"
}

Snapshotting a webpage

Send a JSON body with a url to have Rivermark fetch and extract the page once, giving you a stable reference that won't change if the page does:

curl -X POST https://api.rivermark.ai/upload \
  -H "Authorization: Bearer $RIVERMARK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "url": "https://acmecoffee.co/about" }' | jq

{
  "id": "rmf_cj4hbr01k0007v2x8n6tqz8f",
  "name": "acmecoffee.co/about",
  "mime_type": "text/html",
  "size": 51203,
  "kind": "webpage"
}

Response

Supported types

Currently supported:

• Images (PNG, JPEG, WebP, SVG, AVIF)
• Text files (.txt, .md, CSV)
• HTML/CSS files
• .zip archives (guidelines, asset drops, nested content)
• Webpage URLs (fetched and extracted once)
• Canva designs

On request:

• PDFs
• Figma designs
• .docx (Word) documents
• .pptx (PowerPoint)

Uploads are limited to 50 MB per file; larger archives should be split or trimmed. There is no limit on the number of files.

Notes

• Files are private to your organization.
• Deleting a design does not delete the files you uploaded — manage uploads from the API dashboard.
• There is no charge for storage; the cost of reading references is included in the requests that use them.