Building jev-git: Sub-Second Git Reflex Gate in Rust

Git hooks typically suffer from two distinct problems:

1. Regex linters: Fast, but brittle. They flag dummy test strings as private keys and miss base64-encoded credentials or obfuscated destructive commands.
2. Generative LLM reviewers: Context-aware, but take 4 to 8 seconds per commit and cost real money on every staged change.

I built jev-git to provide semantic pre-commit checks with sub-second execution.

+-------------------+        +----------------------+        +---------------------+
| git commit / push |        | jev-git (Rust)       |        | TypeSafe AI (Jev)   |
| Staged Git Diff   | -----> | Diff Parser & Filter | <----> | /v1/systemone       |
+-------------------+        | Blocking ureq Client |        | 70-90ms Noul Eval   |
                             +----------------------+        +---------------------+
                                        |
                                        +---> Exit 0: Clean commit allowed
                                        +---> Exit 1: Commit blocked with reason

How It Works

jev-git hooks directly into the Git lifecycle as a standard executable on PATH (git-jev or git jev).

When triggered:

1. It gathers staged file changes using git diff --cached --unified=3.
2. It strips binary files and vendor directories (node_modules, target, dist).
3. It sends the filtered diff payload to TypeSafe AI's Jev model (jev-latest).
4. Jev returns a calibrated probability (Noul) for three specific failure modes:
   • Hardcoded API credentials or private keys.
   • Destructive shell scripts (e.g., unintended deletions, unvalidated system calls).
   • Hallucinated or malformed configuration keys.
5. If the risk probability exceeds 0.20, jev-git prints the exact offending diff hunks and aborts the commit with exit code 1.

The entire round-trip completes in approximately 80ms over standard broadband connections.

Quickstart

Install the single static binary:

# Clone and build
git clone https://github.com/AkashPriyadarshii/jev-git.git
cd jev-git
cargo build --release
cp target/release/git-jev ~/.local/bin/

# Install hook in your repository
git jev install

Now, any standard git commit automatically runs the verification gate:

# Test staged changes on demand
git jev check

# Pipe arbitrary diffs into the gate
git diff HEAD~1 | git jev check

Binary Characteristics

The binary is compiled with Link-Time Optimization (LTO) and stripped:

• Binary size: 1.8MB statically linked.
• Runtime memory: Under 12MB peak RSS.
• Zero daemon processes: Runs once per commit and exits immediately.