What it is
Remote (CCR) sessions gain keepalive messages after a turn stops, currently off by default
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.277.
Presence across releases
1Build by build
2One row per release since the first build this name was read out of. Absent means the build was read and the name was not in it, never mined means no bundle for that release was ever archived, and a declared type or a default is only ever what that release's own bundle stated.
First cited
1The earliest release whose published evidence quoted tengu_ccr_keepalive_after_stop_enabled was v2.1.277, 18 Sep 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table above.
Gate readings
1| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.277 read on another version | Off in both readings | off | off | off |
Two arms, because they disagree: this account is the one account this site reads and anonymous is a baseline with no identity attached. A reading says nothing about your account, and off cannot rule out a rollout both readings sit outside of. What these readings can and cannot show.
Flag server, over time
4| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| this account | on | 2026-09-21T15:25:05Z | 2026-09-22T05:45:05Z | v2.1.278 |
| anonymous | on | 2026-09-21T14:35:05Z | 2026-09-22T05:45:05Z | v2.1.278 |
| this account | off | 2026-09-17T22:30:05Z | 2026-09-21T14:35:05Z | v2.1.274 to v2.1.278 |
| anonymous | off | 2026-09-17T21:45:04Z | 2026-09-21T14:25:05Z | v2.1.274 to v2.1.278 |
One row per unbroken stretch of one reading, newest first, from snapshots taken every twenty-five minutes or so. No longer carried is not off: it means the flag server stopped returning the gate at all, which is what a retired experiment looks like. The version column is what was installed when the reading was taken, not what caused it.
Names beside it
Every feature flag in the inventory starting tengu_ccr, up to twelve of them.
tengu_ccr_bridgeBridge worker sessions record which account launched them, but the bridge is off. v2.1.138
tengu_ccr_bundle_max_bytesNo description from anybody. v2.1.138
tengu_ccr_bundle_seed_enabledIf a folder is too big to seed a cloud session, you now see the size, cap and biggest files. v2.1.227
tengu_ccr_bundle_uploadMost of this release's changed code is the build system moving modules, not features changing. never mined
tengu_ccr_context_build_after_resume_enabledNo description from anybody. v2.1.275
tengu_ccr_delta_rehydrateNo description from anybody. v2.1.181
tengu_ccr_disk_watchdogA new gated background watchdog can warn or take action when disk space runs low v2.1.268
tengu_ccr_drop_unwatched_stream_eventsTwo new remote flags control telemetry event-holding and dropping unwatched stream events v2.1.268
tengu_ccr_event_hold_enabledTwo new remote flags control telemetry event-holding and dropping unwatched stream events v2.1.268
tengu_ccr_exclude_dynamic_restore_killswitchA session setting for excluding dynamic sections now survives a worker restart in headless mode. v2.1.261
tengu_ccr_handoff_metadataHanding a session to the cloud can include a snapshot of your checkout, off by default. v2.1.242
tengu_ccr_hook_keepalive_enabledRemote and CCR sessions now hold a keepalive open while certain hooks are running v2.1.271
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the feature flag does. All feature flags.