Catch FSD violations as you code — before they hit main

The Feature-Sliced Design linter that lives in your editor and your Pull Requests. No CI, no config, and no code ever leaves your machine.

Install for VS Code Get for Chrome

Using Cursor, Windsurf or Antigravity?Get it on Open VSX

Zero-config setup. 100% Local & Private — no code ever leaves your machine.

FSD Guard reviewing a GitHub Pull Request: inline diff with a public-API-bypass violation and the FSD Guard details panel

The Problem

Why Feature-Sliced Design breaks in practice

Maintaining architectural guidelines is notoriously hard. Without automation, guidelines quickly erode under velocity pressure.

Rule Evasion

Rules only live in your head

FSD's layer isolation guides are dense. Developers easily forget whether Features can import from Entities, leading to quiet dependency spaghetti.

Review Bottleneck

Manual review doesn't scale

Checking imports line-by-line during PR reviews is exhaustively tedious. Violations slip past reviewers focused purely on business logic.

Setup Fatigue

CI linters are heavy & slow

Configuring ESLint / Steiger rules in CI blocks developer pipelines, takes weeks to approve, and slows down local build performance.

Two Modes. Zero Setup.

Designed for instant architectural sanity

PR Inline Check Mode

The extension injects warning banners directly beneath offending lines inside GitHub & GitLab diff views. Developers resolve violations before even requesting review.

Full Repository Audit

Click the extension icon on any repository to analyze the entire codebase: a report grouped by file, plus an Architecture view with the dependency graph, circular dependencies and a health score.

Architecture viewNew in 0.2

See your whole repo as a dependency graph

The repository audit now maps every slice, laid out by FSD layer from app down to shared. Edge thickness is the number of imports, node size is how much a module is depended on.

Upward and cross-slice imports light up as violations; clean edges stay dashed.
Circular dependencies are detected and highlighted, with an “only cycles” filter.
Click any edge or module to see the exact files and lines behind it.
Search modules, filter to violations only, pan and zoom.

Get for Chrome

Chrome extension → open any repo → Scan repository → Architecture

FSD Guard Architecture view: a repository's slices laid out by layer, with violating imports highlighted in red and orange

Trace any module

Hover a slice and everything else fades out: who depends on it, what it pulls in, and its instability.

Layers & Matrix overviews

Collapse dozens of slices into six layers, or read the layer-to-layer heatmap — rows import columns, red cells hold violations.

Health score, cycles & hotspots

The share of clean edges, violations by type and by layer, circular dependencies, orphans and the most-depended-on modules.

MR delta

Compare a Pull/Merge Request with its target branch: which violations it introduces and which it fixes.

Quick check of changed lines, or a full compare of both branches.

Product tour

FSD Guard in 35 seconds

From a Pull Request check to the full architecture map of your repository.

Simple Flow

From install to feedback in 15 seconds

Zero integrations, zero packages to install. Just extension magic.

Install Extension

Add FSD Guard to your Chromium-based browser in one-click from the Web Store.

Open any Pull Request

Navigate to any GitHub or GitLab Pull/Merge Request. No repo token or API key required.

See violations inline

Offending import lines are marked with clean, actionable architectural warnings.

Capabilities

Superpowered FSD analysis features

Inline diff highlighting

Violations are illuminated inside standard git diff viewports. Fits smoothly into your routine.

Deep Details Panel

Hover any violation to understand the structural logic behind why FSD restricts the import.

Copy for AI assistants

Export violations instantly in an optimized prompt format for ChatGPT, Claude, or Copilot.

Instant Repository Audit

Scan any codebase in seconds for a health score, circular dependencies and a layer-by-layer dependency graph — from open source to enterprise.

Multi-language core

Fully supports TypeScript, JavaScript, Vue, Svelte, and experimental framework setups.

Flexible configuration

Uses custom alias rules and layers if your codebase adapts the FSD standard.

FSD Ruleset

What FSD Guard checks automatically

We validate your imports against the core pillars of Feature-Sliced Design specifications.

Layer Hierarchy

Layers can only import from lower-level layers (e.g. Page → Feature, never vice-versa).

Strict Validation

Slice Isolation

Slices within the same layer cannot import from each other to prevent tight coupling.

Violations Highlighted

Public API Protection

Imports must traverse the public API (index.ts) of slices rather than internal files.

Strict Validation

Internal Cross-Imports (@x)

Identifies and flags circular references utilizing aliases or internal sub-paths.

Cross-Import Guard

Alternatives

How FSD Guard stacks up

Core ParameterFSD Guard ExtensionESLint / Steiger (CI)Manual Code Review

Setup Required

FSD Guard ExtensionZero (Browser only)

ESLint / Steiger (CI)Weeks of config

Manual Code ReviewNone

Analyze Third-Party Repos

FSD Guard ExtensionYes (Any open PR)

ESLint / Steiger (CI)No

Manual Code ReviewYes (Slowly)

Feedback Speed

FSD Guard ExtensionInstant on-page load

ESLint / Steiger (CI)CI pipeline lag

Manual Code ReviewReview meeting delay

Violation Explanations

FSD Guard ExtensionDetailed interactive tooltips

ESLint / Steiger (CI)Generic terminal text

Manual Code ReviewDepends on reviewer

Architecture Map & Cycles

FSD Guard ExtensionDependency graph + cycle detection

ESLint / Steiger (CI)Extra tooling needed

Manual Code ReviewWhiteboard sketches

One-click AI Export

FSD Guard ExtensionBuilt-in copy formatter

ESLint / Steiger (CI)Manual copy-paste

Manual Code ReviewNo

Privacy Shielding

FSD Guard Extension100% Local

ESLint / Steiger (CI)Variable

Manual Code ReviewCode leaked online

Who is it for

Fitted for high-velocity teams

For Leads

Accelerated Code Review

Lead engineers delegate architectural audits to the extension, saving cognitive power for business critical functions.

For Onboarding

Junior Dev Onboarding

Guide newer engineers through practical FSD structure organically. Feedback arrives inside PR drafts, before reviews.

For Maintenance

Legacy Repository Auditing

Evaluate code health instantly when inheriting un-typed projects or reviewing freelance deliveries.

For Open Source

Quick Third-Party Assessments

Explore architecture quality inside external open source PRs before integrating libraries into your ecosystem.

Your code never leaves your browser

FSD Guard processes all validation internally inside your browser context. We operate no cloud analytics servers, collect zero telemetry, and capture no code files. Safe for highly restricted corporate repositories.

No API keys needed
100% Local logic
No remote servers