{"version":"2.1.286","anchor":"cross-machine-sendmessage-file-transfer-availability-check","canonical_anchor":"cross-machine-sendmessage-file-transfer-availability-check","heading":"Refused cross-machine file sends through SendMessage now say why","tier":"notice","area":"SendMessage","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.286\/e\/cross-machine-sendmessage-file-transfer-availability-check","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.286","markdown":"### Refused cross-machine file sends through SendMessage now say why\n\n`SendMessage` now checks cross-machine file transfer before and after the permission ask and before sending, and names the reason when refused\n\n**Unclear.** What `allow_send_file` falls back to when the server sends nothing is not known.\n\n**What**\n\n`SendMessage` is the tool Claude uses to send messages, and sometimes files, to another Claude Code session. Whether a file may go to a session on another machine used to be decided once by a fixed check. It is now checked three times:\n\n- before asking you for permission\n\n- again after you answer\n\n- again just before the file is sent\n\nWhen the cause is a residency restriction or the file-sending switch `allow_send_file` is off, the refusal uses the standard message. Otherwise it reads: `Cross-machine file transfer is unavailable: <reason> Same-machine (uds:) transfers still work.`\n\n**Why**\n\nA refusal now tells you the actual reason and that sending to a session on the same machine still works. A policy change that happens while you are answering the permission prompt is also caught before the file goes out.\n\n- Area: SendMessage\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 2\/5"}