Quick start

Tavero needs Node 20 or later and a Vite or Next project on React 19 that runs in dev mode. It writes only to <project>/.tavero/.

Install

npm i -D tavero
npx playwright install chromium

The second command downloads the browser Tavero scans with. Run it once per machine.

Log in

If the app has a login, save a session once. A browser opens, you log in by hand, and the session is kept for later scans.

npx tavero login --url http://localhost:5173/login

With test credentials you can do it headlessly with --email and --password. Do not give an agent a person's real password.

Scan

npx tavero scan --url http://localhost:5173

Tavero starts the dev server if nothing answers on that port, finds the routes and renders each one at mobile, tablet and desktop widths. Every element is mapped to the React component and the source line that rendered it. A full scan takes a few minutes.

Read the findings

npx tavero findings
npx tavero finding f_2d0ccc6aa1

findings lists the problems worst first: id, severity, rule, title and how many places. finding shows one with its evidence: the file and line, the current value and the expected token or component. Text output is capped at 20 rows (up to 200 with --limit), and every read command takes --json.

Give your agent the context

npx tavero context

A brief of about 1,500 tokens: the stack, the tokens, the canonical button and card components with their files and props, the dominant radius, spacing and type, and the open problems. Agents read it before writing UI. For the full loop through MCP, see MCP and clients.

Fix and rescan

After a change, rescan only the routes and rules it touched. It takes seconds.

npx tavero scan --url http://localhost:5173 --routes /billing --rules colors
npx tavero diff

A finding is closed when diff lists it as resolved. For a person, npx tavero report writes a self-contained HTML report into the scan folder, and npx tavero ui opens the panel.