Gateguard

This is a pre-action hook that blocks Claude's first edit or file write and forces it to gather concrete facts first: what imports this file, what the data schema actually looks like, what the user literally asked for. The claim is that investigation beats self-evaluation, backed by two A/B tests showing a 2.25 point quality jump. MultiEdit gets gated per file, destructive bash commands get gated every time, routine commands once per session. The hook is included and you flip it on via hooks.json, or install the full package for per-project config. If you work on codebases where Claude guesses at date formats or misses downstream callers, this adds friction in exactly the right place.

skills.sh installs: 5.4K
GitHub stars: 300.3K
last updated: Aug 21, 2026

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Install

$ npx -y skills add affaan-m/ecc --skill gateguard --agent claude-code

Installs into .claude/skills of the current project.

Files

GateGuard — Fact-Forcing Pre-Action Gate

A PreToolUse hook that forces Claude to investigate before editing. Instead of self-evaluation ("are you sure?"), it demands concrete facts. The act of investigation creates awareness that self-evaluation never did.

When to Activate

Working on any codebase where file edits affect multiple modules
Projects with data files that have specific schemas or date formats
Teams where AI-generated code must match existing patterns
Any workflow where Claude tends to guess instead of investigating

Core Concept

LLM self-evaluation doesn't work. Ask "did you violate any policies?" and the answer is always "no." This is verified experimentally.

But asking "list every file that imports this module" forces the LLM to run Grep and Read. The investigation itself creates context that changes the output.

Three-stage gate:

1. DENY  — block the first Edit/Write/Bash attempt
2. FORCE — tell the model exactly which facts to gather
3. ALLOW — permit retry after facts are presented

No competitor does all three. Most stop at deny.