uxlint MCP server

uxlint

Audit any website's UX the way a design-literate reviewer would: contrast, tap targets, type scale, colour discipline, scan patterns, landmarks. Every finding comes with a prescriptive fix an agent (or a human) can apply directly. It's designed to sit in a coding agent's loop (MCP) and be iterated against until green.

A real run, start to finish: auditurl → Grade B, a 2.39:1 contrast error and three CTAs in three different accent hues → the fix → verifyfix → Grade A. Every number in it came back from the tools; only the waiting was cut.

This is the CLI: a small, single static Rust binary. It drives a Chrome/Chromium you already have installed over the DevTools protocol (no Node, no Playwright, no headless-browser download), captures what a page looks and reads like, and sends that to uxlint's hosted server, which does the actual grading. The rules engine, the calibrated thresholds, and the LLM judge all live server-side, so the client never needs updating when a rule changes.

┌──────────────────────────┐        POST /v1/audit {snapshots}        ┌──────────────────────────┐
│ uxlint (this binary)     │ ───────────────────────────────────────▶ │ uxlint-server (hosted)    │
│ drives YOUR Chrome (CDP) │ ◀─────────────────────────────────────── │ rules engine + LLM judge  │
└──────────────────────────┘        report {findings + fixes}         └──────────────────────────┘

Install

curl -fsSL https://uxlint.net/install.sh | sh    # detects OS/arch, verifies checksum

Or with mise — its github backend pulls the matching build from GitHub Releases, verifies it, and updates on mise up:

mise use -g "github:uxlint-net/uxlint-cli[rename_exe=uxlint]@latest"

or pin it in a project's mise.toml:

[tools]
"github:uxlint-net/uxlint-cli" = { version = "latest", rename_exe = "uxlint" }

Or build from source (needs a recent stable Rust toolchain and a Chrome/Chromium on PATH):

git clone https://github.com/uxlint-net/uxlint-cli && cd uxlint-cli
cargo build --release
./target/release/uxlint --version

Quickstart

uxlint auth login                                        # opens your browser, saves a token
uxlint audit --base https://your-site.com --routes /,/pricing

First time auditing your own project? uxlint init picks (or creates) a site to attach reports to and writes a uxlint.toml so every future audit in this directory just works:

uxlint init
uxlint audit --base http://localhost:5173 --routes /,/pricing

Exit code 1 on findings above the configured severity → drop it straight into CI (see .github/workflows/ for a template, or the uxlint-net/uxlint-action GitHub Action).

Hiding elements from an audit (uxlint-hide)

Some on-page chrome isn't product UI and shouldn't be judged: a dev/staging environment banner, a "DEV" marker, a debug toolbar, a Storybook/preview affordance. Add the class uxlint-hide to any such element and the audit removes it — it's display:none from first paint, so it never appears in a screenshot and is invisible to the collector (it seeds no findings):

<div class="env-banner uxlint-hide">STAGING</div>

The class is inert on your real site — it does nothing unless the audit is running, because the stylesheet that hides it (.uxlint-hide { display: none !important; }) is injected only by uxlint's browser, before the page's own scripts run. Style your element however you like the rest of the time. It applies in every capture path — the crawl, goal-walk tests, and fix previews.

MCP (use it from a coding agent)

Claude Code, one command:

/plugin marketplace add uxlint-net/uxlint-cli
/plugin install uxlint@uxlint

Shortened. The full README is on GitHub.