Background sessions are Claude Code conversations that keep running without a terminal attached. After an update, Claude Code normally restarts background sessions still running the old version, both in its regular sweep and in a quick burst after taking over.
Both of those now skip a session that is using an LLM gateway, a service some organizations put between Claude Code and the model. Claude Code works out whether a gateway is in use from the environment, your user settings and policy settings, and writes a small mark file for the session. If it cannot write that file, the log says "background session: could not write its LLM gateway mark". If it cannot read the environment or settings while checking, it logs that as well.
The burst still waits 15000 ms and restarts 3 sessions at a time by default.
A background session that depends on a gateway is no longer restarted by an update in a way that could leave it without that gateway.
tengu_bg_prewarm_burst_delay_ms 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 v2.1.319: not a boolean we can read
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.
tengu_bg_prewarm_burst_concurrency 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 v2.1.319: not a boolean we can read
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.
tengu_bg_gateway_mark 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 v2.1.319: on
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 v2.1.319. It isn't a statement about your account. What a flag value here can and cannot tell you
New in this build: tengu_bg_gateway_mark