/effort selections are now persisted to user settings / Claude Code v2.1.126

What

Choosing an effort level with the /effort slash command now writes the value to your user settings file, so it persists across sessions and across Claude Code restarts. Previously, an /effort change only mutated in-memory session state — when you started a fresh session the selection reverted.

Usage

/effort high     # persisted to userSettings.effortLevel = "high"
/effort medium   # persisted
/effort auto     # clears the persisted effortLevel (writes undefined)

Details

The command now invokes the settings writer (I6("userSettings", { effortLevel: $ })) in addition to the existing in-session update.
If the write fails (read-only filesystem, permissions, etc.), the command returns a new error message: Failed to set effort level: <reason>.
The session-scoped guard for non-allowed values is unchanged: only low, medium, high, and xhigh propagate to remote sessions; other values still produce the existing "session-scoped and won't reach the remote process" warning.
/effort auto likewise clears the persisted effortLevel (writes undefined), so resetting works symmetrically.

Evidence

/effort command handler now persists to settings (search for the new error string "Failed to set effort level: " and the call I6("userSettings", { effortLevel"). The prior version's handler had no I6("userSettings", ...) call at all.

Strings lifted out of the shipped bundle, so the claim above can be checked against them.