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Introduction

What is PRECC?

PRECC (Предиктивная коррекция ошибок для Claude Code) is a Rust tool that intercepts Claude Code bash commands via the official PreToolUse hook mechanism. It fixes errors before they happen, saving tokens and eliminating retry loops.

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The Problem

Claude Code wastes significant tokens on preventable mistakes:

  • Wrong-directory errors – Running cargo build in a parent directory that has no Cargo.toml, then retrying after reading the error.
  • Retry loops – A failed command produces verbose output, Claude reads it, reasons about it, and retries. Each cycle burns hundreds of tokens.
  • Verbose output – Commands like find or ls -R dump thousands of lines that Claude must process.

The Four Pillars

Исправление контекста (cd-prepend)

Определяет, когда команды вроде cargo build или npm test выполняются в неправильном каталоге, и добавляет cd /правильный/путь && перед выполнением.

GDB Debugging

Detects opportunities to attach GDB for deeper debugging of segfaults and crashes, providing structured debug information instead of raw core dumps.

Session Mining

Mines Claude Code session logs for failure-fix pairs. When the same mistake recurs, PRECC already knows the fix and applies it automatically.

Automation Skills

A library of built-in and mined skills that match command patterns and rewrite them. Skills are defined as TOML files or SQLite rows, making them easy to inspect, edit, and share.

How It Works (30-Second Version)

  1. Claude Code is about to run a bash command.
  2. The PreToolUse hook sends the command to precc-hook as JSON on stdin.
  3. precc-hook runs the command through the pipeline (skills, directory correction, compression) in under 3 milliseconds.
  4. The corrected command is returned as JSON on stdout.
  5. Claude Code executes the corrected command instead.

Claude never sees the error. No tokens wasted.

Adaptive Compression

Если команда завершается ошибкой после сжатия, PRECC автоматически пропускает сжатие при следующей попытке, чтобы Claude получил полный несжатый вывод для отладки.

Live Usage Statistics

MetricValue
Hook invocations–
Tokens saved–
Saving ratio–%
RTK rewrites–
CD corrections–
Hook latency– ms (p50)

Цифры являются оценками. Каждая предотвращённая ошибка избегает полного цикла повтора: вывод ошибки, рассуждение модели и команда повтора. These numbers update automatically from anonymized telemetry.