PRECC — Predictive Error Correction for Claude Code

PRECC saves ~34% of Claude Code costs through three pillars: fixing bash commands before they fail, compressing tool output, and reducing context token usage via semantic search and file compression. Ships as a single Rust binary.

Three Savings Pillars

Pillar 1: Command Correction & Output Compression

• Fixes wrong-directory commands — Detects when cargo build or npm test is run in the wrong directory and prepends cd /correct/path &&
• Prevents repeated failures — Learns from past session failures and auto-corrects commands that would fail the same way
• Compresses CLI output — Rewrites commands to use RTK for 60-90% smaller output
• Suggests GDB debugging — When a command fails repeatedly, suggests precc debug

Pillar 2: Semantic Code Search (cocoindex-code)

• Intercepts grep/rg and redirects through AST-aware semantic search
• Built into the precc-hook binary; no extra scripts needed
• Understands code structure across 28+ languages, saving ~70% of search tokens

Pillar 3: Context File Compression

• Strips filler words from CLAUDE.md and memory files via precc compress
• Reduces tokens loaded on every API call (~30% compression)
• Backups saved automatically, revertible with precc compress --revert

Install

curl -fsSL https://raw.githubusercontent.com/yijunyu/precc-cc/main/scripts/install.sh | bash
precc init

Usage

Once installed, PRECC works automatically as a PreToolUse hook.

# Mine existing session history for failure-fix patterns
precc ingest --all

# View what PRECC has learned
precc skills list

# View unified savings report (all three pillars)
precc savings

# Semantic code search (requires cocoindex-code)
ccc init && ccc index
ccc search "authentication middleware"

# Compress context files
precc compress --dry-run   # preview
precc compress             # compress
precc compress --revert    # revert

Measured Results

Links

• GitHub: https://github.com/yijunyu/precc-cc
• ClawHub: https://clawhub.ai/skills/precc
• cocoindex-code: https://github.com/cocoindex-io/cocoindex-code
• token-saver: https://clawhub.ai/skills/token-saver
• RTK: https://github.com/rtk-ai/rtk