Start a user flow session. Opens a browser, navigates to the URL, and returns the first page snapshot with a screenshot plus Core Web Vitals, accessibility score, and network summary. Claude then drives the simulation step-by-step using the "step" tool, roleplaying as the persona.

Workflow: start_session → step (repeat) → end_session

The persona definition is returned so you can roleplay as them — adopt their tech literacy, patience, goals, and behavioral patterns when deciding what to click next.

v0.3: Supports device emulation via device_profile parameter. Use list_devices to see all options.

Execute one step in a session. Tell the MCP what action to take (click, type, scroll, etc.) and optionally record your persona thoughts, emotional state, and any friction you noticed. Returns the resulting page state with a new screenshot.

Actions: click, type, scroll, scroll_up, navigate, select, hover, press_key, wait

v0.3: Smart selector fallback — if your CSS selector fails, the engine will try alternative strategies (data-testid, aria-label, text content) automatically.

End a session and get the final report. Closes the browser, computes friction score and emotional arc, and returns the full session transcript with all recorded thoughts, friction points, and recommendations.

v0.3: Report now includes Core Web Vitals, accessibility score, network summary, and console errors.

Get the current page state and screenshot without performing any action. Useful for re-examining the page or checking if lazy-loaded content has appeared.

Run a WCAG accessibility audit on the current page of a session using axe-core. Returns a score (0-100), all violations with WCAG criteria, and actionable fixes.

Inspect cookies, localStorage, and sessionStorage for the current page. Identifies tracking cookies and calculates total cookie size.

Export all network requests captured during the session as a HAR 1.2 log. Useful for analyzing network performance, finding slow requests, and debugging API calls.

Compare two base64 PNG screenshots pixel-by-pixel. Returns match percentage and a visual diff image highlighting differences. Useful for detecting UI regressions or verifying changes.

Create a custom persona for testing. Define their name, goals, tech literacy, patience, device preference, and accessibility needs. Returns the persona definition to use with start_session.

Fast single-page scan. Navigates to the URL, captures a screenshot, extracts all interactive elements, headings, forms, and error messages. Returns everything to you for analysis — no session state required.

List all built-in personas with their full trait definitions. Use this to choose a persona for start_session, or to understand each persona before roleplaying as them.

List all available device emulation profiles (phones, tablets, desktops). Use the device key with start_session's device_profile parameter.

Fast automated walk using heuristic-based navigation (no AI reasoning). Runs the full flow autonomously and returns a report. Use this for quick scans when you don't need to drive step-by-step.

Run the automated heuristic walker for multiple personas on the same URL and compare their experiences. Fast but less nuanced than step-by-step simulation.