{"version":"2.1.286","anchor":"read-ahead-of-attachments-gated-by-tengu-amber-ferry","canonical_anchor":"read-ahead-of-attachments-gated-by-tengu-amber-ferry","heading":"Remote sessions add a relay transport, arrival timing, and earlier attachment preparation","tier":"soon","area":"Attachments","url":"https:\/\/changelogs.core-directive.com\/v\/2.1.286\/e\/read-ahead-of-attachments-gated-by-tengu-amber-ferry","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.286","markdown":"### Remote sessions add a relay transport, arrival timing, and earlier attachment preparation\n\nRemote sessions gain a 'relay' transport, record when the server received each message, and can start preparing attachments before file downloads\n\n**What**\n\nRemote sessions are Claude Code sessions that run on a server and receive your messages over the network. This release changes how those messages are delivered and timed, and adds a new way to prepare attached files earlier.\n\n- A new `relay` transport joins the ways a remote session can connect. The live event stream transport gains `onDeliveredCallback` and `connectionSessionWriters`.\n\n- Queued messages now carry `aheadOfRead` and an optional `serverReceivedWallMs`.\n\n- The session message format gains an optional `server_received_wall_ms`, the session server's clock time when it received the request. Claude Code copies it into the turn result as `user_message_server_received_wall_ms`.\n\n- A new server-controlled switch, `tengu_amber_ferry` (built-in fallback: off), turns on an `aheadOfFiles` mode for incoming user messages. In that mode, preparing attachments starts before the file downloads finish, and the existing read-ahead behind `tengu_polished_reef` is skipped. Before, attachments were prepared by a plain call, with read-ahead controlled only by `tengu_polished_reef`.\n\n- The attachment timing record gains an `aheadOfFiles` field, and turn timing also records `aheadOfRead`.\n\n**Why**\n\nThese changes measure and aim to shorten the delay before a remote or cloud session starts working on a message, especially one with attached files. Nothing has been read about `tengu_amber_ferry`, so whether the earlier attachment preparation is in use is not known.\n\n- Flag `tengu_amber_ferry`: Not enough to say (read for one account on one subscription tier against v2.1.286; this account: no value returned, anonymous baseline: no value returned, compiled default: 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.\n- Flag `tengu_polished_reef`: Not enough to say (read for one account on one subscription tier against v2.1.286; this account: no value returned, anonymous baseline: no value returned, compiled default: 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.\n- Area: Attachments\n- Tier: Nothing to try yet\n- Useful: 2\/5\n- Signal: 3\/5\n- Present in the build but not switched on"}