tengu_curious_river
A Claude Code feature flag, read out of the shipped bundle. It has been in the build since v2.1.305, including the newest one read.
In Anthropic cloud sessions, a running MCP task stops keeping its cloud container up after a set number of hours, 168 by default
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.305.
In the changelogs
2Releases whose published page names tengu_curious_river.
-
v2.1.305
Long-running MCP tasks in cloud sessions stop holding the container up after a time limit
In Anthropic cloud sessions, a running MCP task stops keeping its cloud container up after a set number of hours, 168 by default
gate cited by this entry
-
v2.1.305
Cloud sessions stop keeping a container running for an MCP task after 168 hours
In Anthropic cloud sessions, a running MCP task stops keeping the cloud container up after a time limit, 168 hours by default
gate cited by this entry
Gate readings
1| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.305 read on another version | Not enough to say | no value returned | no value returned | not a boolean we can read |
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
8| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| this account | 168 | 2026-10-22T00:10:04Z | 2026-10-22T05:30:05Z | v2.1.307 to v2.1.308 |
| anonymous | 168 | 2026-10-20T00:35:04Z | 2026-10-22T05:30:05Z | v2.1.304 to v2.1.308 |
| this account | no longer carried | 2026-10-21T21:10:07Z | 2026-10-21T21:10:07Z | v2.1.306 |
| this account | 168 | 2026-10-21T21:09:42Z | 2026-10-21T21:09:42Z | v2.1.307 |
| this account | no longer carried | 2026-10-21T02:50:06Z | 2026-10-21T02:50:06Z | v2.1.305 |
| this account | 168 | 2026-10-21T02:45:34Z | 2026-10-21T02:45:34Z | v2.1.306 |
| this account | no longer carried | 2026-10-20T19:55:06Z | 2026-10-20T19:55:06Z | v2.1.304 |
| this account | 168 | 2026-10-20T19:52:45Z | 2026-10-20T19:52:45Z | v2.1.305 |
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.
First cited
1The earliest release whose published evidence quoted tengu_curious_river was v2.1.305, 20 Oct 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 below.
Presence across releases
1Build by build
4One 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.
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.