What
For an API request that has to finish before a deadline, Claude Code can now pass along how much time is left as a budget for waiting after a rate limit (a temporary "slow down" answer from the server). This happens only when a configuration value named rateLimitFailFastEnabled is exactly true, so it is off unless that value is supplied.
Why
In practice, when it is turned on, a request that hits a rate limit should give up rather than wait past its deadline.
Names in the bundlerateLimitFailFastEnabled
Feature flag
tengu_auto_mode_config 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 v2.1.282: 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.
Read once, for one account on one subscription tier, against v2.1.282. It isn't a statement about your account. What a flag value here can and cannot tell you
Flag reading moved
The flag server now returns {"editRemovalCap":3000,"editRemovalVisibility":true,"enabled":"enabled","envOnboarding":true,"gitStatusType":true,"gitStatusUploads":false,"jsonlTranscript":true,"outcomeVisibility":false,"repoVisibility":true,"sameTurnSiblingContext":true,"severityByModel":{"claude-opus-4-8":{"t1":45,"t2":35},"claude-opus-4-8[1m]":{"t1":45,"t2":35},"claude-sonnet-5":{"t1":25,"t2":35},"claude-sonnet-5[1m]":{"t1":25,"t2":35}},"severityBySite":{"compactFabCheck":"on","handoff":"on","investigator":"on","sandboxNetwork":"on","workflowGate":"on"},"twoStageClassifier":true} for tengu_auto_mode_config, read as this account.
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
Flag reading moved
The flag server now returns {"editRemovalCap":3000,"editRemovalVisibility":true,"enabled":"enabled","gitStatusType":true,"gitStatusUploads":false,"jsonlTranscript":true,"outcomeVisibility":false,"repoVisibility":true,"sameTurnSiblingContext":true,"severityByModel":{"claude-opus-4-8":{"t1":45,"t2":35},"claude-opus-4-8[1m]":{"t1":45,"t2":35},"claude-sonnet-5":{"t1":25,"t2":35},"claude-sonnet-5[1m]":{"t1":25,"t2":35}},"severityBySite":{"compactFabCheck":"on","handoff":"on","investigator":"on","sandboxNetwork":"on","workflowGate":"on"},"twoStageClassifier":true} for tengu_auto_mode_config, read as this account.
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
Flag reading moved
The flag server now returns {"editRemovalCap":3000,"editRemovalVisibility":true,"enabled":"enabled","envOnboarding":true,"gitStatusType":true,"gitStatusUploads":false,"jsonlTranscript":true,"outcomeVisibility":false,"repoVisibility":true,"sameTurnSiblingContext":true,"severityByModel":{"claude-opus-4-8":{"t1":45,"t2":35},"claude-opus-4-8[1m]":{"t1":45,"t2":35},"claude-sonnet-5":{"t1":25,"t2":35},"claude-sonnet-5[1m]":{"t1":25,"t2":35}},"severityBySite":{"compactFabCheck":"on","handoff":"on","investigator":"on","sandboxNetwork":"on","workflowGate":"on"},"twoStageClassifier":true} for tengu_auto_mode_config, read as this account.
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
Flag reading moved
The flag server now returns {"editRemovalCap":3000,"editRemovalVisibility":true,"enabled":"enabled","gitStatusType":true,"gitStatusUploads":false,"jsonlTranscript":true,"outcomeVisibility":false,"repoVisibility":true,"sameTurnSiblingContext":true,"severityByModel":{"claude-opus-4-8":{"t1":45,"t2":35},"claude-opus-4-8[1m]":{"t1":45,"t2":35},"claude-sonnet-5":{"t1":25,"t2":35},"claude-sonnet-5[1m]":{"t1":25,"t2":35}},"severityBySite":{"compactFabCheck":"on","handoff":"on","investigator":"on","sandboxNetwork":"on","workflowGate":"on"},"twoStageClassifier":true} for tengu_auto_mode_config, read as this account.
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
Flag reading moved
The flag server now returns {"editRemovalCap":3000,"editRemovalVisibility":true,"enabled":"enabled","envOnboarding":true,"gitStatusType":true,"gitStatusUploads":false,"jsonlTranscript":true,"outcomeVisibility":false,"repoVisibility":true,"sameTurnSiblingContext":true,"severityByModel":{"claude-opus-4-8":{"t1":45,"t2":35},"claude-opus-4-8[1m]":{"t1":45,"t2":35},"claude-sonnet-5":{"t1":25,"t2":35},"claude-sonnet-5[1m]":{"t1":25,"t2":35}},"severityBySite":{"compactFabCheck":"on","handoff":"on","investigator":"on","sandboxNetwork":"on","workflowGate":"on"},"twoStageClassifier":true} for tengu_auto_mode_config, read as this account.
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
It is unclear which request this applies to and which configuration supplies `rateLimitFailFastEnabled`.