Unclear Which MCP servers pass the policy check that allows file attachments is not stated.
MCP servers are outside programs that give Claude extra tools. A tool whose description declares anthropic/fileInputs can now be given paths to files on your computer. Claude Code then:
- computes a fingerprint of each file
- asks the server for permission through its
authorize_uploadtool - uploads the files to the addresses the server returns
- replaces the file paths with the references the server returns
This applies only to servers that pass a policy check, and it sits behind a setting Claude Code receives from Anthropic's servers. When it fails, Claude Code shows messages such as "The files could not be attached." or "This organization's policy does not allow attaching files here."
This gives MCP servers a new way to receive your local files. If you see one of these attachment messages, the upload was blocked or failed and the tool did not get the file.
tengu_walnut_tiller Not enough to sayNothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.
This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.296: off
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Read once, for one account on one subscription tier, against v2.1.296. It isn't a statement about your account. What a flag value here can and cannot tell you
Which MCP servers pass the policy check that allows file attachments is not stated.
New in this build: tengu_walnut_tiller