MCP server Mochi

Mochi

Browser companion for AI assistants. Browser automation MCP + persistent project memory + in-page hint messaging, all in one Claude Code plugin.

A QA-tester MCP for AI assistants — with memory.

Each AI session runs inside its own Chrome tab group (your other tabs are untouched). What's new: every successful action is auto-traced, and the agent can save the trace as a named workflow scoped to a domain. Next time you ask "test the login flow on staging", the agent replays the saved workflow with cached selectors — no re-discovery, no re-screenshotting. If a selector breaks (refactor, A/B test, redesign), the engine self-heals by ARIA role + name and updates the cache.

                 selector cache + workflow store
                  (file-based, <project>/.continuum/)
                              ▲
AI client (Claude Code / Codex / Cursor)
        │  stdio (MCP)                 ▲
        ▼                              │
   server/  ──── auto-launches Chrome ─┴─▶  Chrome
        │  WebSocket                              │
        ▼                                         ▼
 extension/ background.js  ◀──────────────  manifest V3 extension
                       │
                       ▼
              session = { tab group, primary tab, tab set, CDP }

Layout

Directory	What it is
server/	Node MCP server. WS server (port 9009) + file-based memory + workflow replay engine.
extension/	Chrome MV3 extension. Owns the tab group, CDP attachments, and DOM helpers.
mcp/	Reference clone of upstream Browser MCP (not used; archival).

Memory (selector cache, workflows, runs) lives in <project>/.continuum/ alongside the Continuum chain data — pure files, no database. Override with SUPER_TESTER_DATA_DIR.

Install (one plugin, one extension, done)

Mochi is a Claude Code plugin bundling browser automation, context-chain memory, and popup hint messaging. The server is pre-bundled into a single file (server/dist/server.bundle.mjs) by GitHub Actions on every push to the default branch — so installing means cloning the repo. No npm install, no native binaries, no setup script.

Install from GitHub (recommended)

# Inside any Claude Code session:
/plugin marketplace add DevZonayed/Mochi
/plugin install mochi@mochi

That's it for the plugin. Then load the Chrome extension once:

chrome://extensions → Developer mode → Load unpacked → select
  ~/.claude/plugins/cache/mochi/mochi/0.6.0/extension

Restart Claude Code. Press ⌘⇧M (macOS) or Ctrl+Shift+M (other) on any tab to send a hint with picked elements + screenshot.

Install from a local checkout (if hacking on the plugin itself)

/plugin marketplace add /absolute/path/to/your/Mochi/checkout
/plugin install mochi@mochi

If you change source files, rebuild the bundle before reloading:

cd /path/to/Mochi/server && npm install && npm run build

Then /reload-plugins inside Claude (or /plugin uninstall mochi && /plugin install mochi@mochi for a clean refresh).

The plugin auto-registers:

• Two MCP servers — browser (automation tools) and continuum (recall tool)
• Seven slash commands — /continuum:checkpoint, /continuum:recall, /continuum:status, /continuum:dream, /continuum:feedback, /continuum:rename, /continuum:render
• Seven hooks — SessionStart, PreCompact, SessionEnd, PreToolUse, PostToolUse, Stop, UserPromptSubmit
• The /browser skill

For the in-page hint modal: press ⌘⇧M (macOS) or Ctrl+Shift+M on any page once the extension is loaded.

Migrating from the older super-tester plugin name

If you had an earlier install when the plugin was called super-tester, run:

/plugin uninstall super-tester
/plugin marketplace remove super-tester

…then follow the install steps above using the new mochi names. Your .continuum/ chain data, screenshots, and feedback queue are tied to your project dir (not the plugin name) — they survive the rename.

Updating

Whenever new versions of mochi land (bumped version in plugin.json):

/plugin update mochi

Claude Code re-copies the source files into its plugin cache and switches the active install over. MCP servers respawn on next Claude restart. For hook / command / skill changes only, /reload-plugins works mid-session.

Legacy install script

The older ./install.sh script (which edited ~/.claude.json directly) is still in the repo but is now redundant with the plugin route. Don't use both at the same time — pick one.

./install.sh --uninstall   # remove the legacy .claude.json entry if present

Tools (MCP)

65 tools, grouped by purpose.

Design-QA loop (0.9.0+). An agent can run a design-QA pass and drop a comment on every issue via browser_comment_add — those comments appear to you as pins in Comment Mode (they share the extension's storage). You review/edit them client-side, then the agent reads the session back (browser_comment_list) and fixes everything in bulk, marking each browser_comment_resolve. Drive it with /mochi:design-qa [focus] and /mochi:design-qa fix.

Notifications, not focus-stealing (0.5.0+). Automation never raises the Chrome window to the OS foreground on its own — it posts a click-to-focus notification titled Mochi · <project> instead, so it won't yank you out of your editor. Clicking the toast brings that session's window forward. The agent can ping you on purpose via browser_request_attention. Requires a one-time "reload unpacked extension" (new notifications permission); on macOS, enable Google Chrome under System Settings → Notifications (the popup walks you through it).

Session + tabs

Tool	What it does
browser_session_start	New tab group + primary tab. Pass newWindow:true to spawn a fresh window. Posts a click-to-focus notification instead of stealing focus.
browser_session_end	Detach debugger, ungroup or close session tabs.
browser_request_attention	Post an OS notification asking the human to look (captcha, choice, or "done — come look"). Click focuses the window.
browser_navigate	Navigate primary tab, wait for load.
browser_open_tab	Open new tab inside the session group.
browser_list_tabs	List session tabs + CDP attachment state.
browser_close_tab	Close a specific session tab.

Discovery + interaction

Tool	What it does
browser_text	Compact visible text lines, optionally filtered by query. Use before snapshot for reading/searching content.
browser_links	Compact visible links with text, href, selector ref, and box.
browser_snapshot	ARIA tree with stable refs + pixel boxes. Defaults to compact, viewport-only, redacted, depth-limited, and 12KB capped.
browser_snapshot_query	Search the stored snapshot by text/name/role/ref/tag and return tiny excerpts.
browser_snapshot_node	Return one compact subtree from the stored snapshot by ref, text, or query path.
browser_click	Click by selector (CDP). Pass intent to cache the selector for next time.
browser_click_at	Click at pixel coords (CDP).
browser_type	Focus + clear + insertText. Pass intent to cache.
browser_press_key	Real keyboard event (CDP).
browser_scroll	Absolute {x,y} or relative {deltaX,deltaY}.
browser_go_back / browser_go_forward	History navigation.
browser_wait	Sleep up to 60s.
browser_screenshot	PNG/JPEG (viewport / fullPage / elementRef).

Viewport + window

Tool	What it does
browser_window_resize	Resize/move/maximize the actual window (only safe with newWindow).
browser_emulate_viewport	Device Mode via CDP. Presets + custom width/height/DPR/UA.
browser_clear_emulation	Reset viewport overrides.

Assertions

Tool	What it does
browser_assert	Verify url-contains, url-equals, title-contains, element-exists, element-missing, text-contains, text-equals. Returns {ok, got}.

QA truth & coverage (0.5.0)

The verdict-driven core of an exhaustive QA pass. Render != Works: a control that paints on screen is not a verified control. These tools enumerate every actionable element, drive each one, and prove what actually happened.

Tool	What it's for
browser_audit_interactives	Enumerate every actionable control on the page (scope:"all"|"viewport", limit, includeHidden). The coverage backbone — returns {selector, role, accessibleName, visible, inViewport, disabled, hasClickHandler, box} per element so nothing goes UNTESTED.
browser_act_and_observe	Perform one action (click/type/navigate/press_key/click_at) and classify the result: WORKS / NO-OP / ERROR / NAVIGATES. A NO-OP (clickable but nothing changed) is a dead control = defect. Returns urlChanged, domChanged, networkDelta, consoleDelta.
browser_assert_no_errors	One-call health gate: ok=false if any console error/uncaught exception or any >=400/failed request happened since the page loaded (sinceNavigation default, or sinceMs, with ignoreUrlContains). Failed-request entries include .body.
browser_wait_for_response	Block until a matching network response arrives (urlGlob/urlContains, method, statusGte/statusLt, timeoutMs). Proves a write actually persisted instead of guessing from the UI.
browser_page_assets	Hash the live page assets (script/css/document) with sha256 + a pageHash. Confirm the live bundle hash == the built hash so you never test a stale cached deploy.
browser_set_storage	Deterministic auth/state seeding — set localStorage, sessionStorage, and cookies (or clear) in one call so a flow starts from a known logged-in state.

Enhancements to existing tools in 0.5.0:

• browser_navigate now accepts hardReload (cache-bypass load) and disableCache (persist cache-off for the tab) — pair with browser_page_assets to defeat stale bundles.
• browser_console_messages accepts sinceNavigation:true to scope to the current page (the fix for a stale pre-navigation buffer reading as a false "no errors"); level:"error" includes uncaught exceptions.
• browser_network_requests accepts sinceNavigation, sinceMs, and includeBody; error responses (>=400/failed) include the captured response body automatically, so an "Internal server error" tells you why (e.g. SMTP misconfig) instead of guessing.
• browser_click now reports disabled controls (fails loudly with "element is disabled" rather than silently passing) and retries a transient not-found once.
• browser_session_health accepts heal:true to re-attach the debugger to session tabs.

File uploads

Tool	What it does
browser_upload_stage	Stage a file into the per-project library at .continuum/uploads/. Accepts path, https url, dataUrl, or base64. Returns a stable stashId (sha256-based, idempotent) reusable across many uploads.
browser_upload_file	Attach a file to a page target via a strategy chain: direct (DOM.setFileInputFiles) → intercept (file-chooser dialog) → drop (synthesized DataTransfer + DragEvent) → paste (synthesized ClipboardEvent). Bypasses the native OS file picker entirely. Target by selector, ref, trigger, or auto: { near }. Smart-wait confirms upload (preview thumbnail / 2xx upload response / custom successSelector).

Sources can be inlined into browser_upload_file or pre-staged with browser_upload_stage; staging dedupes by sha256, so the same logo across ten sites is fetched/decoded once and reused. Frame-traversal handles same-origin iframes automatically. See docs/superpowers/specs/2026-05-19-browser-file-upload-design.md for the full design.

Playbooks (personal ops memory)

Tool	What it does
browser_playbook_list	List playbooks under .continuum/playbooks/, filter by origin/tag/verifiable.
browser_playbook_get	Return one playbook with meta + body sections + workflow JSON.
browser_playbook_save	Create/update a playbook (validates frontmatter and required sections).
browser_playbook_delete	Remove a playbook + workflow + screenshots.
browser_playbook_match	Score-match playbooks against a URL, intent, or task description.
browser_playbook_run	Replay a playbook (with self-heal) using provided inputs; recursively executes composes/next chains; returns verdict + evidence.
browser_playbook_propose_update	Given a successful trace, create or update the matching playbook. Inputs and steps auto-inferred.
browser_playbook_secret_check	Validate that a playbook's type: secret inputs are resolvable (env or .continuum/secrets/). Returns availability only — never values.
browser_playbook_seed_from_codebase	Static-analyze the project's frontend (Next.js / Vite / CRA) and emit draft playbooks per route + form. Solves cold-start on in-house apps.
browser_playbook_diff_accept	Bless a run's per-step screenshots as the new visual reference; bumps playbook_version.
browser_playbook_export	Export one or more playbooks to a single JSON bundle file. Includes embedded base64 screenshots.
browser_playbook_import	Import a playbook bundle (file / inline JSON / https URL). Supports overwrite + rewriteOrigin (e.g., staging → production).
browser_playbook_dashboard	Generate a self-contained HTML dashboard from the library; opens in the active browser session.

v1.5 capabilities:

• Typed secrets: inputs[].type: secret resolves at runtime from ${env:VAR} or ${secret:name} (reads .continuum/secrets/<name>.txt, which is chmod 0700 with an auto-protective .gitignore). Secret values never appear in .continuum/runs/ traces or promoted playbook bodies.
• Codebase-derived drafts: point browser_playbook_seed_from_codebase at this project and it walks your routes (Next.js App/Pages Router, Vite, CRA), extracts forms + data-testids + aria-labels, and emits draft playbooks per route. Password fields auto-typed as secret.
• Visual diff regression: during browser_playbook_run, each step's screenshot is compared (pixelmatch) against the playbook's reference. warn between 5–20% diff; fail ≥20% (configurable per playbook). Use browser_playbook_diff_accept to bless intentional UI changes.

See docs/superpowers/specs/2026-05-20-playbooks-v1-5-design.md.

v2 capabilities (Sharing & Polish):

• 1Password integration: inputs[].type: secret refs accept ${1password:vault/item/field} (alias ${op:...}). When the op CLI is installed and signed in, values are resolved via op read at run time and never logged.
• Vue + SvelteKit codebase seeding: Nuxt projects (nuxt.config.*) and SvelteKit projects (svelte.config.* + @sveltejs/kit) are detected by browser_playbook_seed_from_codebase in addition to Next.js / Vite / CRA.
• Blocked-verdict UX: browser_playbook_run returns verdict: "blocked" with a needs[] array (one entry per missing required input + a hint per source) instead of throwing. The main agent uses the hints to prompt the user (or fix env) and then retries.
• Cross-project playbook bundles: browser_playbook_export writes a single JSON containing markdown + workflow + base64 screenshots; browser_playbook_import restores them anywhere. Supports overwrite + origin rewrite for staging → production migration.
• HTML dashboard: /mochi:playbook ui (or browser_playbook_dashboard) generates a self-contained dashboard with search, tag filters, and inline drill-down per playbook.

See docs/superpowers/specs/2026-05-20-playbooks-v2-design.md.

Combined with the bundled qa-tester subagent and the smart-router rule in plugins/qa/CLAUDE.md, the playbook library is your personal ops memory — each browser task you do once becomes replayable, chainable, and scheduleable. Main Claude routes verifiable + repeatable tasks to the isolated qa-tester subagent (which returns a pass/fail verdict + evidence) while operational tasks (multi-step, decisive, may need mid-flow input) stay in the main conversation and use playbooks as guidance.

Slash commands:

• /qa <task> — dispatch the qa-tester subagent for a verifiable browser task.
• /mochi:playbook list|show|run|delete|match [args] — manage playbooks.
• /mochi:schedule-playbook <id> — wire up cron via the host's schedule skill.
• /mochi:unschedule-playbook <id> — cancel a scheduled playbook.

See docs/superpowers/specs/2026-05-20-personal-ops-playbooks-design.md for the full design.

Memory: selector cache (per origin)

Tool	What it does
browser_recall_selector	"Do I already know how to find X on this site?" Returns cached selector or null.
browser_forget_selector	Drop a cached entry.
browser_list_selectors	Inspect the cache.

Memory: workflows

Tool	What it does
browser_workflow_save	Persist current session's auto-traced actions as a named workflow.
browser_workflow_run	Replay. Cached selector → self-heal by role+name → screenshot on miss.
browser_workflow_list / _get / _delete	Manage workflows.
browser_workflow_export / _import	Portable JSON (commit alongside your app's tests).
browser_run_history	Last N runs of a workflow.

Compact inspection ladder

Use the smallest inspection tool that can answer the current question:

1. browser_text {query?, limit?} for page copy, search results, lists, and visible facts.
2. browser_links {query?, limit?} for navigation choices.
3. browser_snapshot for clickable refs and visible actionable UI.
4. browser_snapshot_query for targeted search inside the stored snapshot.
5. browser_snapshot_node for the one subtree you need.
6. browser_snapshot {mode:"full", scope:"all", maxBytes:0} only as an explicit last resort.

This keeps Claude Code, Codex, and parallel agents from flooding their context with full-page accessibility trees.

Visual placement loop

browser_snapshot      → compact tree with refs + boxes
browser_screenshot    → image (viewport / fullPage / elementRef)
   ↓
agent correlates ref ↔ box ↔ pixel position
   ↓
browser_click {ref, intent:"…"}    ← intent caches the selector

Resize vs. emulate — when to use which

Read this carefully — these two tools are NOT interchangeable:

• browser_emulate_viewport changes the page's real JS layout. It drives CDP Emulation.setDeviceMetricsOverride, so it does change window.innerWidth / window.innerHeight and does flip matchMedia / CSS media queries. This is the tool you use for responsive and media-query testing — breakpoints, mobile layouts, @media rules all respond to it.
• browser_window_resize only moves/sizes the OS-level Chrome window. It does NOT affect window.innerWidth or matchMedia — the page's JS layout is unchanged. Use it only when you genuinely need real OS window dimensions (e.g. screenshotting the full chrome of a large monitor).

A common past mistake was conflating the two — or assuming emulate_viewport "only affects screenshots." It does not; it changes JS layout.

Goal	Tool
Test a real responsive layout at iPhone size	browser_emulate_viewport {preset:"iphone-15-pro"} (changes innerWidth/matchMedia, includes touch + UA)
Verify a layout breakpoint at exactly 768px wide	browser_emulate_viewport {width:768, height:1024} (media queries respond)
Test how the OS window behaves at a real 2560×1440 monitor	browser_window_resize {width:2560, height:1440} (only safe in a session-owned window; JS layout unchanged)
Reset back to native	browser_clear_emulation

emulate_viewport is preferred for layout/responsive testing — it's deterministic, doesn't disturb anything else, matches Chrome DevTools' Device Mode, and actually changes what the page's JavaScript sees. window_resize is for when you genuinely need real OS-level window dimensions.

Exhaustive QA coverage mode

Beyond one-off checks, Mochi can run an exhaustive QA pass (/qa exhaustive) that enumerates every actionable control with browser_audit_interactives, drives each one through browser_act_and_observe, gates every page and action with browser_assert_no_errors, and assigns one of five verdicts to each control: WORKS, NO-OP (defect), ERROR (defect), NAVIGATES, or DISABLED. Results are recorded in a verification ledger with provenance stamping, and a built-in honesty gate refuses to report a run as "pass" while any control is still UNTESTED/UNCERTAIN — the rule is never "everything works" but "N of M controls verified — here is each result, and here is what I could NOT verify and why." Hard-won tooling quirks live in a persistent tooling-gotchas note so they're never re-learned.

Memory model

Two layers, stored as plain JSON files under <project>/.continuum/ (no database, no native bindings).

1) Selector cache — keyed by (origin, intent)

Every browser_click / browser_type call may carry an intent ("click sign in button", "email field"). On success, the resolved selector is cached at (origin, intent). The agent can short-circuit discovery by calling browser_recall_selector before snapshotting:

browser_recall_selector {intent:"click sign in button"}
  → {found:true, selector:'button[aria-label="Sign in"]', last_box:{...}}
browser_click {ref:'button[aria-label="Sign in"]', intent:"click sign in button"}

The cache survives Chrome restarts, project reloads, server restarts.