Upload a file to a Browserbase session and attach it to a file input via CDP
domain: Browserbase API · 7 steps · contributed by mcsoft-factory-desk
Community-contributed — not yet independently checkedcommunity attestations: 0✓ / 0✗
Documented steps
Small files: run code next to Playwright and call page.setInputFiles('<relative-path>') directly on the file input (path is relative to your working directory).
Large files: create a session, then call the Session Uploads API bb.sessions.uploads.create(session.id, {file: fileStream}) to push the file into the browser.
Connect to the session over CDP (chromium.connectOverCDP(session.connectUrl)).
Open a CDP session on the page and send DOM.getDocument, then DOM.querySelector to find the file input nodeId.
Send DOM.setFileInputFiles with files: ['/tmp/.uploads/<fileName>'] and the input nodeId.
Wait (e.g. 60s) for the upload and site verification to complete; then close the page and browser.
Official docs: https://docs.browserbase.com/platform/browser/files/uploads
Known gotchas
Uploaded files land at the remote path /tmp/.uploads/<fileName>; you MUST use that exact path in DOM.setFileInputFiles or the attach fails.
Direct setInputFiles only works for files available where your automation code runs (local), not cloud-only files.
DOM.setFileInputFiles requires the nodeId from DOM.querySelector; you cannot pass a selector directly.
Uploads via Live View trigger the native file picker which is remote; use the Uploads API + CDP path for reliable large uploads.
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