effortLevel
A Claude Code settings key, read out of the shipped bundle. It was in the build from v2.1.138 and was gone by v2.1.284.
Set a default effort level for models without a saved level of their own
Anthropic's own wording. Read off All settings, captured 2026-10-22.
In the changelogs
23Releases whose published page names effortLevel.
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v2.1.301
Organizations can push more settings remotely, and the output style is now reported
Remotely managed settings now accept keys such as
effortLevel,outputStyleandattribution, and Claude Code's settings report includes the output stylefound in this entry's text
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v2.1.287
Effort level setting is skipped in some cases
Claude Code now sometimes skips applying an
effortLevelsetting, depending on a check of the model and levelfound in this entry's text, named in this entry
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v2.1.287
Effort level updates from a controlling program are skipped when unchanged
When a controlling program sets an effort level that is already in effect, Claude Code now skips re-applying it
found in this entry's text, named in this entry
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v2.1.287
Some effort level updates are now skipped instead of applied
An update that sets effortLevel is now ignored, without being reported, when a new check on the model and its current state says so
found in this entry's text, named in this entry
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v2.1.280
Model effort-level resolution changed for userSettings source
Model effort level from user settings alone is no longer always honored automatically
found in this entry's text
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v2.1.277
update_settings tool can now target more than localSettings, including userSettings.effortLevel
The internal update_settings tool can now write userSettings.effortLevel, not just localSettings
found in this entry's text
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v2.1.277
Effort level command validation gains a dedicated error message
New dedicated error message when update_settings is called with an invalid effortLevel
found in this entry's text, named in this entry
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v2.1.274
Org admins can force their default reasoning-effort level onto users
Org admins can now force their default reasoning effort level onto all users
found in this entry's text
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v2.1.271
New remote-control-plane commands: MCP reconnect/toggle, session titling/renaming, task stop/backgrounding, and flag settings
Remote control connections can now reconnect/toggle MCP servers, rename sessions, stop tasks, and set effort/ultracode flags
found in this entry's text
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v2.1.242
Cloud sessions accept only seven live settings changes
Only seven settings can be changed mid-run against a cloud session; others are rejected by name.
found in this entry's text
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v2.1.240
Saving a default effort level can now scope it to one model
Your saved default effort could apply per model instead of everywhere, but that is off.
found in this entry's text
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v2.1.239
New
modelSettingsconfig key holds per-model effortA new modelSettings config key stores an effort level per model, from low to xhigh.
named in this entry, found in this entry's text
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v2.1.239
Per-model effort level in settings, behind a gate
You could set an effort level per model in settings, but the lookup is gated off.
named in this entry, found in this entry's text
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v2.1.238
Model picker names both models when a session override is in place
The model picker now names both your session model and configured model when they differ.
found in this entry's text
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v2.1.238
Effort store split, with a settings writer
Session effort and saved-setting effort are now stored separately, and only written when one actually changes.
found in this entry's text
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v2.1.235
Cloud/remote task creation carries an effort level, and teleport passes a permission mode
Remote/cloud task creation now carries an effort level and teleport passes a resolved permission mode
found in this entry's text
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v2.1.234
Remote Control can read and change the session's effort level and ultracode
A remote client driving your session can now see and change effort level and toggle ultracode.
found in this entry's text
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v2.1.126
/effortselections are now persisted to user settingsfound in this entry's text
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v2.1.111
New "xhigh" Effort Level
found in this entry's text
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v2.1.76
/effortSlash Commandfound in this entry's text
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v2.1.73
Simplified Effort Level Setting
found in this entry's text
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v2.1.72
Effort Level "max" and Persistence
found in this entry's text
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v2.0.46
Effort Level Configuration
found in this entry's text
First cited
7The earliest release whose published evidence quoted effortLevel was v2.1.126, 30 Apr 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.
1 further span in the ledger name it. The list above is the earliest first and stops at 6.
Presence across releases
2Build by build
150One 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 settings key does. All settings keys.