Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.236 Home All releases olderv2.1.235 v2.1.237newer
Claude Code v2.1.236

Fullscreen is offered as a trial, and turns itself off after repeated failed launches

You'll notice
Useful4 Signal3
Fullscreen

Accepting fullscreen now runs as a trial, and two crashed launches disable it on that machine.

Feature flag
tengu_amber_creek Not enough to say

Nothing 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 v2.1.236: on

tengu_pewter_brook On for this account, and not off by default

The flag server returned on for the one account this site reads, and nothing in this release compiles it off by default. The compiled default is shown below, and says which it is when we cannot read one: a fifth of gates compile in a string or a number rather than on or off, and most published releases have no gate table behind them at all. No client can see what the server returns for your account.

This account: on · anonymous baseline: on · compiled default in v2.1.236: on

Read once, for one account on one subscription tier, against v2.1.236. It isn't a statement about your account. What a flag value here can and cannot tell you

/tui fullscreenCLAUDE_CODE_NO_FLICKER
What

Accepting the fullscreen renderer prompt no longer writes the setting straight away. Claude Code relaunches into a trial and only saves tui: "fullscreen" if the session stays healthy. Separately, each fullscreen launch is recorded before the first frame and cleared 10 seconds after it; a launch that dies first counts as a strike, and 2 strikes disable fullscreen on that machine for that version. /tui fullscreen retries, and CLAUDE_CODE_NO_FLICKER=1 still overrides.

Details
  • The renderer decision gained two new reasons: upsell_trial_on for a trial session and crash_auto_off for the self-disable.
  • Strike state lives in the global config as fullscreenBootPending, fullscreenBootStrikes and fullscreenAutoDisabled, the last stamped with the build version (2.1.236). While the stamp matches the running version fullscreen stays off and the upsell is suppressed; an update clears it.
  • One strike falls back to the classic renderer for that launch only. Pending records go stale after 10 minutes on the same host, 30 days across hosts.
  • The canary applies to interactive sessions entering fullscreen via settings, trial, the Anthropic default, or the downsell/gb paths. It is skipped for env-forced fullscreen and when CLAUDE_CODE_EXIT_AFTER_FIRST_RENDER is set.
  • When it trips, stderr says: "Claude Code's fullscreen renderer has repeatedly failed to start on this machine, so it has been turned off here. Run /tui fullscreen to try it again (this also resets after an update)."
  • Bare /tui now explains why the classic renderer is active, distinguishing a sticky repeated-failure disable from a single unfinished launch.
  • Telemetry: tengu_fullscreen_crash_auto_off, carrying sticky, strikes, new_strikes, pending age and the entry path fullscreen would have used.
  • Neither path is behind a remote flag. Fullscreen-by-default itself still sits behind tengu_amber_creek and tengu_pewter_brook, both falling back to off.
Evidence

crashAutoOff: !1,, crash_auto_off, Claude Code's fullscreen renderer has repeatedly failed to start on this machine, so it has been turned off here. Run /tui fullscreen to try it again (this also resets after an update)., (fullscreen was turned off on this machine after it repeatedly failed to start; /tui fullscreen retries), tengu_fullscreen_crash_auto_off, upsell_trial_on

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

See this entry in the whole of v2.1.236 →