slicegate

English · Tiếng Việt

Every slice of AI-written code passes a gate.

A gated development process for teams of AI coding agents (Claude Code): small slices, independent gates, an append-only verdict ledger, guards that run in git hooks, and mutation testing by risk zone to prove the tests actually guard the rules.

It was extracted from a real project — a multi-exchange trading platform built by several agents working in parallel — by separating the mechanism (reusable) from the project-specific content. Every project parameter lives in one file: slicegate.toml.

Status: 0.3.0 (formerly gatekit) — core + 10 industry packs. Document templates, CLI and guard messages in English and Vietnamese; identifiers in code are English.

Why

AI agents write code fast, but they fail in four recurring ways. slicegate blocks each one with something measurable:

What it looks like

An agent writes a pallet quote with a bare weight and a cut-off built from datetime.utcnow():

def quote(weight, distance_km):
    cutoff = datetime.utcnow().replace(hour=10, minute=0)
    total_weight = weight * 1.1
    return cutoff, total_weight * distance_km

The pre-commit hook (logistics pack) blocks the commit:

$ git commit -m "feat(rating): pallet pricing [S-14]"
🔴 naive_time — 1 violation(s) (blocks: timestamps without a time zone ⇒ cut-offs, SLAs and ETAs shift by the server's time zone)
   [naive_time] src/shipping/pallet.py:5 — `datetime.utcnow()` creates a timestamp without a time zone — pass `timezone.utc` / `tzinfo=`
🔴 unit_suffix — 2 violation(s) (blocks: quantities without units ⇒ kg/lb, km/mi, °C/°F get mixed: wrong rates, overloaded vehicles, spoiled cold chain)
   [unit_suffix] src/shipping/pallet.py:4 — quantity `weight` carries no unit in its name (e.g. `_kg`, `_km`, `_cbm`, `_c`) ∨ `units: ignore <reason>`
   [unit_suffix] src/shipping/pallet.py:6 — quantity `total_weight` carries no unit in its name (e.g. `_kg`, `_km`, `_cbm`, `_c`) ∨ `units: ignore <reason>`
pre-commit: 🔴 slicegate check --fast RED

Every guard states the code defect it blocks, and every guard ships with negative-case self-tests.

Install

Option 1 — Claude Code plugin (recommended)

/plugin marketplace add cuongnpv-create/slicegate
/plugin install slicegate@slicegate

Outside a session: claude plugin marketplace add cuongnpv-create/slicegate && claude plugin install slicegate@slicegate.

The plugin brings:

slicegate hooks install run from the plugin writes the command's path into the git hooks, so pre-commit / pre-push also work for commits made outside Claude Code. After a plugin update (the path changes), run slicegate hooks install again. Note: claude.ai and Cowork do not install plugins with a bin/ directory — this plugin is for Claude Code.

Option 2 — pip

pip install slicegate                                               # or: pipx install slicegate · uvx slicegate
cd your-project && git init                                         # if it is not a repo yet
slicegate init --name "MyApp" --language en --level standard --pack i18n --pack postgres
slicegate hooks install
slicegate check --full

Agents talking in another language but documents in English: --language ja --docs-language en.

After init: fill in CLAUDE.md §1/§2/§7, declare [zones] in slicegate.toml from your real code, then open a coordinator session with docs/governance/COORDINATOR_PROMPT.md.

Levels

Industry packs

Commands

slicegate init        set the process up in a repo (never overwrites existing files without --force)
slicegate check       enabled guards · --fast (pre-commit) · --full (+ mutant anchors + duplicate ledger ids)
slicegate selftest    negative / positive cases of every guard (--all: packs not enabled too)
slicegate zone        risk zone of a diff + the testing it requires; T/K files without a standing mutant suite ⇒ RED
slicegate mutants     anchors · plan · run [--changed BASE]   (MUT_ONLY=id,… to pick)
slicegate ledger      alloc (reserve an id range) · check (duplicates) · open (OPEN conditions) · roll
slicegate debt        debt entries missing columns / overdue
slicegate quota       ratio of governance slices to code slices
slicegate hygiene     report · record — what each guard caught, which defect class has fired 3 times (enough for a new guard)
slicegate report      summary (the SessionStart hook uses --brief)
slicegate migrate     move a project set up under the old name gatekit (see below)

Languages

CLI, guard and tool messages use the same language (src/slicegate/messages.py); override one run with SLICEGATE_LANG=en|vi. Tests test_template_parity and test_messages keep both languages in lockstep: same files and keys, same placeholders and parameters, no Vietnamese left in the en set.

Migrating from gatekit

Before 0.3.0 this tool was called gatekit. Projects set up under that name keep working: gatekit.toml and the .gatekit/ directory are still read (with a reminder), the gatekit command still exists when installed with pip (with a reminder), and GATEKIT_LANG is still honoured. To move for good:

slicegate migrate     # git mv gatekit.toml → slicegate.toml, .gatekit/ → .slicegate/, rewrite hooks, reinstall git hooks
git commit -m "chore: migrate gatekit → slicegate"

The gatekit command and reading the old names will be removed in a later release.

slicegate guards itself

This repo runs slicegate on itself (slicegate.toml at level lite, tests/manifest.tsv, mutants/): slicegate check --full GREEN · 271 pytest tests · 25/25 mutants killed on the guards and the decision rules (risk zones, slice quota, ledger id allocation, ledger rolling, the mutant runner).

When this mutant suite was first built, the first run reported 11/11 "survived": the test command in the copy imported the pip -e package, which pointed back at the original checkout, so the mutants had no effect. slicegate mutants run now warns when every mutant survives.

Case study

docs/case-studies/itsdangerous.md (in Vietnamese) — slicegate set up on pallets/itsdangerous: 6 zone-K mutants exposed a real test gap in key rotation (all 297 tests stayed green with half of the key-trial loop removed); 3 slicegate rough edges found and fixed on the spot (first check went from 12 false REDs to 0).

Layout

.claude-plugin/        plugin.json · marketplace.json · icon.png (the repo is both the plugin and its marketplace)
bin/slicegate          the plugin's command (runs src/ directly)
skills/                /slicegate:init · check · gate · coordinator
hooks/                 the plugin's SessionStart hook
src/slicegate/
  config.py            slicegate.toml → defaults + validation
  messages.py          message catalog en · vi, one t() function
  guards/              guards (core + packs); each has check() · selftest() · DEFECT
  tools/               ledger · debt · slice_quota · risk_zone · guard_hygiene
  qa/mutants.py        mutants on a copy, selected by diff, anchor checks
  scaffold.py          slicegate init / migrate (templates with {{KEY}}, {{#level …}}, {{#pack …}})
  templates/<vi|en>/   CLAUDE.md · governance/ · per-lane ledgers · core agents · hooks
  packs/<pack>/<vi|en>/ agents + documents of each industry pack
tests/                 pytest
mutants/               slicegate's own mutant suites

Roadmap

• More packs: mobile.
• A dashboard over verdict ledgers, OPEN conditions and the guard catch log.

License

MIT.