wtf is gaslighter?

Gaslighter is a Claude Code plugin that steps in right when Claude thinks it has finished a task, and makes it double check whether it actually covered every requirement you asked for. The problem it targets is common: you write several requirements, Claude implements most of them, says the work is done, and one small requirement quietly slips through because it was buried in the middle of a paragraph rather than flagged as an error. It works through a Stop hook, a feature of Claude Code that fires each time Claude tries to end a turn. When that happens, gaslighter asks Claude to re-read the original request and confirm every point was actually addressed, and to fix anything missing before finishing. It is designed not to become annoying: it only nudges once per stop, caps how many times it nudges per session, and stops nudging entirely once Claude either makes no further changes after a nudge or states it is fully confident everything is covered. There are four modes. Lite mode, the default, gives a soft nudge that Claude can still choose to ignore and finish anyway, capped at three nudges per session. Full mode is a hard block that prevents Claude from finishing until it re-verifies, with no cap. Smart mode asks a cheaper model, Haiku, whether anything was actually missed before deciding whether to nudge. Off mode disables the hook entirely. The README includes benchmark results from headless Claude Code coding sessions built around common ways models drop requirements. Compared with a baseline that gets no nudging, both lite and full modes improve the rate of correctly completed requirements, though full mode costs roughly 45 percent more turns since re-checking work takes extra passes. Adding the same reminder text to the system prompt instead of using a hook performed worse than doing nothing at all, suggesting the timing of the interruption matters more than the wording. Installation happens through Claude Code's plugin system, adding the marketplace and installing the plugin with two commands, or the equivalent from the command line. The hook itself is a small Node.js script, so Node needs to be available on your system path. Configuration, including the mode and nudge cap, can be set once and it persists across sessions, or overridden temporarily with environment variables. It is released under the MIT license.