Local Browser MCP Server

Local Browser

Chrome runs on the user's machine and is controlled through the MCPBundles Desktop proxy CDP tunnel. The browser resolves localhost on that same machine — ideal for dev-server QA, interactive debugging, and visual verification.

Capabilities

• Viewport resize — sets window size; also boots Chrome when no session exists yet.
• Navigate — load a URL (including http://localhost:...). Heavy pages may need a shorter wait strategy or a follow-up snapshot before interacting.
• Accessibility snapshot — returns the page tree with opaque element refs (e1, e2, …). Use boxes=true for layout geometry and depth to trim large trees.
• Accessibility audit — run axe-core on the current page for deterministic WCAG violations.
• Layout probe — desktop and mobile layout checks for narrow columns, horizontal overflow, and undersized tap targets.
• Responsive capture — desktop (1440x900) and mobile (390x844) layout summaries in one call; set includeScreenshots=true for inline MCP images.
• Wait for — fixed delay, visible/hidden text, CSS selector(s), js_ready (boolean poll), or js_probe ({streaming, measure} until done). App-agnostic: bring your own selectors/JS for your UI framework.
• Fill form — batch fill with snapshot refs or CSS selectors such as input[name=email]; field type is inferred when omitted.
• Click / type / hover / drag — interact using both a human-readable element label and the exact ref from the latest snapshot. Typing rejects calls missing either field.
• Screenshot — viewport or element-level; returns visual content the model can inspect.
• Directed film beats — capture a still beat after each scene (caption optional); finish the session without leaving screencast mode running. Pairs with Marketing Studio preset=cinematic.
• Screen recording — start screencast, navigate and interact, then stop to obtain a capture asset_id for exports.
• Run JavaScript — evaluate expressions in page context (e.g. read window.location.href after form submit).
• Console and network — list messages and requests for silent failures (404 beacons, hydration errors).

Browser Media (Marketing Studio)

Cinematic tour (recommended):

1. Navigate with wait_until=domcontentloaded (not networkidle — MCPBundles pages keep SSE open).
2. Wait ~4s so entry animations settle, then capture a film beat with a short caption.
3. Repeat navigate + wait + beat for each scene (5–8 beats). For workspace Desktop pairing use /settings/desktop — /settings/connections is a blank redirect stub.
4. Studio: load /studio first, then navigate with ?q=…&autosend=1, wait ~80s, snap after the reply finishes.
5. Stop recording → asset_id; poll recording status until ready.
6. On the Marketing Studio bundle: upsert a project with timeline_json: {"hero_capture_id": "<asset_id>"}.
7. Submit export with preset=cinematic; poll export status for presigned MP4.

Raw screencast: start recording → navigate → wait while still recording → stop recording → export hero_from_capture or product_hunt_kit.

Mixed tour (Ken Burns + screencast): run a YAML journey from product/browser/journeys/studio-mixed-tour.yaml (pass full document as journey_yaml + workspace) — snap beats, flush beats, record Studio autosend, flush screencast. Link both asset ids on the project (beat_capture_id, screencast_capture_id), then Marketing Studio export with preset=mixed or device_mockup.

Chat stream screencast: start recording → navigate → wait with js_probe (returns {streaming, measure} until streaming stops and measure grows) → stop recording. Or selector_gone / selectors_gone for spinners. time is in seconds. Example YAML: product/browser/journeys/chat-autosend-screencast.yaml — pass contents as journey_yaml; uses checked-in probe_preset for Studio QA only.

Typical workflows

Open a page — resize viewport, then navigate. Success means the navigate response includes URL, title, and HTTP 200.

Sign in then continue — navigate to the app's login URL with callbackUrl set to the post-auth destination. Prefer batch form fill with CSS selector refs, or click/type each field with snapshot refs. Redirects can take 1–3 seconds; re-read location from JavaScript evaluation or from the snapshot's URL field.

Review UI quality — after navigate: run the combined UX review for a structured report with clustered ui_findings, optional visual_findings, and a limits block (layout, accessibility, console, form, copy). Set visualCritique=true for PydanticAI vision observations; use captureFrames (desktop, mobile, desktop_scroll_end, mobile_menu_open) for richer shots. Or run responsive capture, accessibility audit, and layout probe individually. Use snapshot with boxes=true or screenshots when you need pixels.

Constraints

• One tab per session — opening additional tabs through the tunnel corrupts CDP state. Navigate within the same tab instead.
• Desktop proxy required — automation routes through the user's MCPBundles Desktop sidecar tunnel.
• Refs come from snapshots — pass opaque ref (e.g. e12) and element (the node's name) from the latest accessibility snapshot to click, type, hover, and drag. Invented refs and CSS selectors are rejected on pointer tools; use batch form fill for CSS selector fills.
• Per-field click + type remains available when a page needs explicit focus handling between fields.
• Separate MCP invocations — run resize, navigate, and interactions as individual calls so failures are attributable.