upload_file

upload_file

Attach a file to a file input.

MCP tool	upload_file
HTTP	POST /browser/upload

For anything you wrote yourself — JSON, CSV, YAML, markdown, plain text — put it straight in text and give it a filename. There is no need to encode it; the server writes the real file and sends it to the browser, which runs on another machine.

Use content (base64) only for binary, and path only for a file already on the server's filesystem. Pass exactly one of the three.

The page reads the file's type from the filename extension, so name it report.csv rather than report. If you give a name without an extension, mime_type is used to pick one.

Parameters

Name	Type	Required	Default	Notes
xpath	string	yes	—
text	string	no	—
filename	string	no	—
mime_type	string	no	—
content	string	no	—
session_id	string	yes over HTTP	—	The session_id returned by /browser/open. Required here.
path	string	no	—
url	string	no	—
wait_timeout	integer	no	30

Returns

Field	Type	Notes
filename	string	The name the page sees for the attached file.
bytes	integer	Size of the file that was sent.
url	string	Current URL after the action.
title	string	Page title after the action.

Errors are 400 for a bad argument, 401 without a token, 500 when the Grid refuses. Over MCP the same failures arrive as a tool error.

Example

MCP

upload_file(xpath="…")

HTTP

curl -X POST $SELENIUM_FLOW/browser/upload \
  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{
    "session_id": "…",
    "xpath": "…"
  }'

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