Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
ElsewhereArea: what it touches
Internal ChangesKind: in v2.1.261,
Internal ChangesSection of the release
Claude-in-Chrome file uploads via the file_upload/browser_batch MCP tool can now skip local input preparation entirely, using a new passThroughChromeFileUploadInput handler instead of the existing prepareChromeFileUploadInput. This pass-through path only kicks in when the MCP server isn't stdio-based, the process isn't CLAUDE_CODE_REMOTE, and CLAUDE_CODE_IS_COWORK is set.
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeFixed Claude in Chrome file_upload failing with "paths: expected array, received undefined" in local Cowork sessions run from the Claude…
