Mtw E2e Runner

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JSON-driven E2E test runner for AI agents. Define browser tests as JSON action arrays and run them in parallel against a Chrome pool (browserless/chrome) with 2

by fastslack

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JSON-driven E2E test runner for AI agents. Define browser tests as JSON action arrays and run them in parallel against a Chrome pool (browserless/chrome) with 28+ built-in actions, visual verification, network debugging, and flaky test detection.

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@matware/e2e-runner

The AI-native E2E test runner that writes, runs, and debugs tests for you.

E2E Runner lets you test your web app without writing test code. Tests are plain JSON — and you don't even have to write that yourself: just ask Claude Code.

🎬 Write a test by asking — then watch it run

_{The live dashboard while a suite runs — every step streams a screenshot into the feed, in real time.}

With the built-in MCP server, creating a test is a conversation — no docs, no syntax to memorize:

You: Create an E2E test for the login flow and run it.

Claude Code: writes the test, runs it in a real browser, and reports back — ✅ login-flow passed in 2.3s · screenshot saved · no network errors.

Behind the scenes Claude just wrote and ran this. A test is just JSON — an ordered list of what a user does:

[
  { "name": "login-flow", "actions": [
    { "type": "goto", "value": "/login" },
    { "type": "type", "selector": "#email", "value": "[email protected]" },
    { "type": "type", "selector": "#password", "value": "secret" },
    { "type": "click", "text": "Sign In" },
    { "type": "assert_text", "text": "Welcome back" },
    { "type": "screenshot", "value": "logged-in.png" }
  ]}
]

No imports, no describe/it, no build step. If you can read it you can write it — or just ask.

Connect it to Claude Code (2 commands):

claude plugin marketplace add fastslack/mtw-e2e-runner
claude plugin install e2e-runner@matware

Now say "create a test for X and run it" — Claude gets 17 MCP tools, slash commands, and specialized agents.

Using a different agent (Cursor, Codex, Copilot, 40+ more)? Install the skill: npx skills add fastslack/mtw-e2e-runner

📖 Contents

	Section	What's inside
🚀	Install & first test	npm setup · run with your own Chrome (no Docker), Obscura, or a Docker pool
✨	What you get	feature overview at a glance
✍️	Writing tests	test format · full action catalog · retries · serial · modules · auth · hooks
🤖	AI integration	Claude Code · OpenCode · 17 MCP tools · visual verification · issue-to-test
📊	Dashboard & insights	live dashboard · learning system · network logs · screenshot capture
🌐	Browser drivers	browserless · cdp · lightpanda · obscura · steel
⚙️	CLI, config & CI	commands · flags · `e2e.config.js` · GitHub Actions · programmatic API

🚀 Install — it's tiny

npm install --save-dev @matware/e2e-runner
npx e2e-runner init        # scaffolds e2e/ with a sample test + config

Then pick how to run the browser. You don't need Docker unless you want the parallel pool:

Option 1 · Use the Chrome you already have — no Docker ⭐

Launch any Chromium browser with a debugging port, then point the runner at it:

google-chrome --headless=new --remote-debugging-port=9222 &   # or brave / chromium / msedge
CHROME_POOL_URL=http://localhost:9222 POOL_DRIVER=cdp npx e2e-runner run --all

Or bake it into e2e.config.js so you never repeat it:

export default {
  baseUrl: 'http://localhost:3000',     // your app — plain localhost, no docker hostname
  poolUrls: ['http://localhost:9222'],
  poolDriver: 'cdp',
};

Nothing to install beyond npm, and baseUrl is just localhost (the browser is on your machine).

Option 2 · Obscura — one tiny binary, no Docker

A single ~30 MB binary with built-in anti-detection. Install once, run it, point the runner at it:

obscura serve --port 9222 --stealth &
CHROME_POOL_URL=http://localhost:9222 POOL_DRIVER=obscura npx e2e-runner run --all

npx e2e-runner pool start (with poolDriver: 'obscura' in your config) prints the exact install command for your OS.

Option 3 · Docker pool — parallel, for CI & big suites

A shared, queue-managed Chrome pool that runs many tests at once:

npx e2e-runner run --all     # the first run auto-starts the Docker pool for you

Requires Docker. Set baseUrl: 'http://host.docker.internal:3000' so the containerized Chrome can reach your app.

Why host.docker.internal (Docker option only)?

With the Docker pool, Chrome runs inside a container, so localhost there means the container — not your machine. host.docker.internal bridges to your host. On Linux (Docker Engine, not Docker Desktop) add --add-host=host.docker.internal:host-gateway, or use your LAN IP. Options 1 & 2 don't have this — the browser is local, so plain localhost just works.

Write your first test

Open e2e/tests/sample.json — a flow is an ordered list of actions:

[
  { "name": "homepage loads", "actions": [
    { "type": "goto", "value": "/" },
    { "type": "assert_text", "text": "Welcome" },
    { "type": "screenshot", "value": "home.png" }
  ]}
]

Run it with npx e2e-runner run --all. Results — pass/fail, timing, screenshots, network errors — print to your terminal and to the web dashboard if it's open.

Add OpenCode (optional)

cp node_modules/@matware/e2e-runner/opencode.json ./
mkdir -p .opencode && cp -r node_modules/@matware/e2e-runner/.opencode/* .opencode/

See OPENCODE.md for details.

Updating

Each install method updates separately — bump the one(s) you use:

# npm dependency (per project)
npm install --save-dev @matware/e2e-runner@latest

# Claude Code plugin
claude plugin update e2e-runner@matware

# MCP-only install (npx caches the package — pin @latest to force a refresh)
claude mcp add --transport stdio --scope user e2e-runner \
  -- npx -y -p @matware/e2e-runner@latest e2e-runner-mcp

[!NOTE] Two gotchas: (1) npx prefers a copy found in the project's node_modules over its own cache — if a project pins an old version, the MCP server and dashboard run that old version, so update the project dependency too. (2) Already-running processes keep the old code in memory: after updating, restart the dashboard and reconnect the MCP server (/mcp → e2e-runner → Reconnect, or restart your session).

✨ What you get

🧪 Zero-code tests — JSON files that anyone on your team can read and write. No JavaScript, no compilation, no framework lock-in.

🤖 AI-powered testing — Claude Code creates, executes, and debugs tests natively through 17 MCP tools. Ask it to "test the checkout flow" and it builds the JSON, runs it, and reports back.

🐛 Issue-to-Test pipeline — Paste a GitHub or GitLab issue URL. The runner fetches it, generates E2E tests, runs them, and tells you: bug confirmed or not reproducible.

👁️ Visual verification — Describe what the page should look like in plain English. The AI captures a screenshot and judges pass/fail against your description. No pixel-diffing setup needed.

🧠 Learning system — Tracks test stability across runs. Detects flaky tests, unstable selectors, slow APIs, and error patterns — then surfaces actionable insights.

⚡ Parallel execution — Run N tests simultaneously against a shared browser pool (browserless, raw CDP, Lightpanda, Obscura, or Steel). Serial mode available for tests that share state.

🎯 Pluggable browser drivers — Pick the engine that fits each test: real Chrome via browserless, Lightpanda or Obscura for fast lightweight runs, Steel for managed sessions. Set driver per test or override the whole run with --driver.

📊 Real-time dashboard — Live execution view, run history with pass-rate charts, screenshot gallery with hash-based search, expandable network request logs.

🔁 Smart retries — Test-level and action-level retries with configurable delays. Flaky tests are detected and flagged automatically.

📦 Reusable modules — Extract common flows (login, navigation, setup) into parameterized modules and reference them with $use.

🏗️ CI-ready — JUnit XML output, exit code 1 on failure, auto-captured error screenshots. Drop-in GitHub Actions example included.

🌐 Multi-project — One dashboard aggregates test results from all your projects. One Chrome pool serves them all.

🐳 Portable — Chrome runs in Docker, tests are JSON files in your repo. Works on any machine with Node.js and Docker.

✍️ Writing tests

Everything about authoring tests — the file format, the full action vocabulary, retries, state isolation, and reuse. Expand what you need:

Test format & file layout

Each .json file in e2e/tests/ contains an array of tests. Each test has a name and sequential actions:

[
  {
    "name": "homepage-loads",
    "actions": [
      { "type": "goto", "value": "/" },
      { "type": "assert_visible", "selector": "body" },
      { "type": "assert_url", "value": "/" },
      { "type": "screenshot", "value": "homepage.png" }
    ]
  }
]

Suite files can have numeric prefixes for ordering (01-auth.json, 02-dashboard.json). The --suite flag matches with or without the prefix, so --suite auth finds 01-auth.json.

Action catalog — navigation, input & interaction

Action	Fields	Description
`goto`	`value`	Navigate to URL (relative to `baseUrl` or absolute)
`click`	`selector` or `text`	Click by CSS selector or visible text content. Text mode also takes `scope: "dialog"`, `visible: true`, `last: true`
`type` / `fill`	`selector`, `value`	Clear field and type text
`wait`	`selector`, `text`, `gone`, or `value` (ms)	Wait for element/text to appear, for `gone` to disappear (spinner/dialog), or fixed delay. Prefer conditions over fixed `value` sleeps
`screenshot`	`value` (filename)	Capture a screenshot
`select`	`selector`, `value`	Select a dropdown option
`clear`	`selector`	Clear an input field
`press`	`value`	Press a keyboard key (`Enter`, `Tab`, etc.)
`scroll`	`selector` or `value` (px)	Scroll to element or by pixel amount
`hover`	`selector`	Hover over an element
`evaluate`	`value`	Execute JavaScript in the browser context
`navigate`	`value`	Browser navigation (`back`, `forward`, `reload`)
`clear_cookies`	—	Clear all cookies for the current page
`wait_network_idle`	optional `value` (idle ms, default 500), `timeout`	Wait until the network has been idle for `value` ms — useful after actions that trigger background requests
`set_storage`	`value` (`"key=val"`), optional `selector: "session"`	Set a `localStorage` key (or `sessionStorage` with `selector: "session"`)
`gql`	`value` (query), optional `text` (variables JSON), optional `selector` (assertion)	Run a GraphQL query/mutation via in-page `fetch`, with the auth token read from `localStorage`. Fails on GraphQL errors. `selector` is a JS expression asserted against the response `r` (e.g. `"r.data.users.length > 0"`). Installs `window.__e2eGql` for later `evaluate` steps

Click by text — when click uses text instead of selector, it searches across common interactive and content elements:

button, a, [role="button"], [role="tab"], [role="menuitem"], [role="option"],
[role="listitem"], div[class*="cursor"], span, li, td, th, label, p, h1-h6

{ "type": "click", "text": "Sign In" }

Assertions — verify text, elements, URLs, counts & network

Action	Fields	Description
`assert_text`	`text`	Assert text exists anywhere on the page (substring)
`assert_no_text`	`text`	Assert text does NOT appear anywhere on the page — opposite of `assert_text`
`assert_text_in`	`selector`, `text`, optional `value: "exact"`	Assert text inside a scoped container. `text` is a case-insensitive regex by default; `value: "exact"` switches to case-sensitive substring
`assert_element_text`	`selector`, `text`, optional `value: "exact"`	Assert element's text contains (or exactly matches) the expected text
`assert_url`	`value`	Assert current URL path or full URL. Paths (`/dashboard`) compare against pathname only
`assert_visible`	`selector`	Assert element exists and is visible
`assert_not_visible`	`selector`	Assert element is hidden or doesn't exist
`assert_attribute`	`selector`, `value`	Check attribute: `"type=email"` for value, `"disabled"` for existence
`assert_class`	`selector`, `value`	Assert element has a CSS class
`assert_input_value`	`selector`, `value`	Assert input/select/textarea `.value` contains text
`assert_matches`	`selector`, `value` (regex)	Assert element text matches a regex pattern
`assert_count`	`selector`, `value`	Assert element count: exact (`"5"`), or operators (`">3"`, `">=1"`, `"<10"`)
`assert_no_network_errors`	—	Fail if any network requests failed (e.g. `ERR_CONNECTION_REFUSED`)
`assert_storage`	`value` (`"key"` or `"key=expected"`), optional `selector: "session"`	Assert a `localStorage`/`sessionStorage` key exists or has a specific value
`assert_visual`	`value` (golden image), optional `selector`, `text` (max diff, e.g. `"0.02"`), `fullPage`, `maskRegions`, `threshold`	Visual regression: compare a screenshot against a golden reference. The first run saves the golden; later runs fail if more pixels differ than the threshold (default 2%) and write a diff image
`get_text`	`selector`	Extract element text (non-assertion, never fails). Result: `{ value: "..." }`

Framework-aware actions — React/MUI without evaluate boilerplate

These actions handle common patterns in React/MUI apps that normally require verbose evaluate boilerplate:

Action	Fields	Description
`type_react`	`selector`, `value`, optional `blur`, `waitAfter`	Type into React controlled inputs using the native value setter. Dispatches `input` + `change` events so React state updates correctly. `blur: true` commits on blur; `waitAfter: "<ms>"` waits after (debounced autocomplete).
`click_regex`	`text` (regex), optional `selector`, optional `value: "last"`	Click element whose textContent matches a regex (case-insensitive). Default: first match. Use `value: "last"` for last match.
`click_option`	`text`	Click a `[role="option"]` element by text — common in autocomplete/select dropdowns.
`select_combobox`	`text`, optional `selector`, `filter`, `openWait`/`filterWait`/`waitAfter`	Open a MUI Autocomplete/Select, optionally type `filter`, then click the option matching `text`. Falls back across `[role="option"]`, `.MuiAutocomplete-option`, `li.MuiMenuItem-root`.
`focus_autocomplete`	`text` (label text)	Focus an autocomplete input by its label text. Supports MUI and generic `[role="combobox"]`.
`click_chip`	`text`	Click a chip/tag element by text. Searches `[class="Chip"]`, `[class="chip"]`, `[data-chip]`.
`click_icon`	`value` (icon id), optional `selector` (scope)	Click an icon by `data-testid`/`data-icon`/`aria-label`/class fragment or SVG `<title>` — MUI, FontAwesome, Heroicons, etc. Clicks the nearest clickable ancestor (button, link, tab).
`click_menu_item`	`text`, optional `selector` (scope)	Click a menu item by text across `[role="menuitem"]`, `.dropdown-item`, `.menu-item`, MUI `MenuItem`.
`click_in_context`	`text` (container text), `selector` (child)	Click a child element inside the smallest container matching `text` — e.g. the delete button of one specific card/row.

// Before: 5 lines of evaluate boilerplate
{ "type": "evaluate", "value": "const input = document.querySelector('#search'); const nativeSet = Object.getOwnPropertyDescriptor(window.HTMLInputElement.prototype, 'value').set; nativeSet.call(input, 'term'); input.dispatchEvent(new Event('input', {bubbles: true})); input.dispatchEvent(new Event('change', {bubbles: true}));" }

// After: 1 action
{ "type": "type_react", "selector": "#search", "value": "term" }

Multi-tab actions — popups, OAuth windows & cross-tab flows

Action	Fields	Description
`open_tab`	`value` (URL), optional `text` (label)	Open a new tab and navigate to the URL (relative to `baseUrl` or absolute). Label defaults to `tab-<n>`
`switch_tab`	`value`	Switch the active tab by label, numeric index, or title/URL match (regex or substring). `"default"` returns to the original tab
`wait_for_tab`	optional `text` (label), `timeout`	Wait for a new tab/popup opened by the app (`window.open`, `target="_blank"`) and make it the active tab
`assert_tab_count`	`value`	Assert the number of open tabs: exact (`"2"`) or operators (`">=2"`)
`close_tab`	optional `value` (label)	Close the current (or named) tab and switch back to the last remaining one

All subsequent actions run in the active tab:

{ "type": "click", "text": "Open report" }
{ "type": "wait_for_tab", "text": "report" }
{ "type": "assert_text", "text": "Quarterly results" }
{ "type": "close_tab" }

Retries & flaky detection

Test-level retry — retry an entire test on failure. Set globally via config or per-test:

{ "name": "flaky-test", "retries": 3, "timeout": 15000, "actions": [...] }

Tests that pass after retry are flagged as flaky in the report and learning system.

Action-level retry — retry a single action without rerunning the entire test. Useful for timing-sensitive clicks and waits:

{ "type": "click", "selector": "#dynamic-btn", "retries": 3 }
{ "type": "wait", "selector": ".lazy-loaded", "retries": 2 }

Set globally: actionRetries in config, --action-retries <n> CLI, or ACTION_RETRIES env var. Delay between retries: actionRetryDelay (default 500ms).

Serial tests — for tests that share state

Tests that share state (e.g., two tests modifying the same record) can race when running in parallel. Mark them as serial:

{ "name": "create-patient", "serial": true, "actions": [...] }
{ "name": "verify-patient-list", "serial": true, "actions": [...] }

Serial tests run one at a time after all parallel tests finish — preventing interference without slowing down independent tests.

Testing authenticated apps

The simplest approach — log in via the UI like a real user:

{
  "hooks": {
    "beforeEach": [
      { "type": "goto", "value": "/login" },
      { "type": "type", "selector": "#email", "value": "[email protected]" },
      { "type": "type", "selector": "#password", "value": "test-password" },
      { "type": "click", "text": "Sign In" },
      { "type": "wait", "selector": ".dashboard" }
    ]
  },
  "tests": [...]
}

For SPAs with JWT, skip the login form by injecting the token directly:

{ "type": "set_storage", "value": "accessToken=eyJhbGciOiJIUzI1NiIs..." }

Or set it globally in config:

// e2e.config.js
export default {
  authToken: 'eyJhbGciOiJIUzI1NiIs...',
  authStorageKey: 'accessToken',
};

Each test runs in a fresh browser context, so auth state is automatically clean between tests.

More strategies: Cookie-based auth, HTTP header injection, OAuth/SSO bypasses, reusable auth modules, and role-based testing — see docs/authentication.md

Reusable modules — extract common flows with $use

Extract common flows into parameterized modules:

// e2e/modules/login.json
{
  "$module": "login",
  "description": "Log in via the UI login form",
  "params": {
    "email": { "required": true, "description": "User email" },
    "password": { "required": true, "description": "User password" }
  },
  "actions": [
    { "type": "goto", "value": "/login" },
    { "type": "type", "selector": "#email", "value": "{{email}}" },
    { "type": "type", "selector": "#password", "value": "{{password}}" },
    { "type": "click", "text": "Sign In" },
    { "type": "wait", "value": "2000" }
  ]
}

Use in tests:

{
  "name": "dashboard-loads",
  "actions": [
    { "$use": "login", "params": { "email": "[email protected]", "password": "secret" } },
    { "type": "assert_text", "text": "Dashboard" }
  ]
}

Modules support parameter validation (required params fail fast), conditional blocks ({{#param}}...{{/param}}), nested composition, and cycle detection.

Hooks — beforeAll / beforeEach / afterEach / afterAll

Run actions at lifecycle points. Define globally in config or per-suite:

{
  "hooks": {
    "beforeAll": [{ "type": "goto", "value": "/setup" }],
    "beforeEach": [{ "type": "goto", "value": "/" }],
    "afterEach": [{ "type": "screenshot", "value": "after.png" }],
    "afterAll": []
  },
  "tests": [...]
}

Important: beforeAll runs on a separate browser page that is closed before tests start. Use beforeEach for state that tests need (cookies, localStorage, auth tokens).

Exclude patterns — skip drafts from --all

Skip exploratory or draft tests from --all runs:

// e2e.config.js
export default {
  exclude: ['explore-*', 'debug-*', 'draft-*'],
};

Individual suite runs (--suite) are not affected by exclude patterns.

🤖 AI integration

The whole point: your agent writes, runs, and verifies tests for you.

Claude Code — plugin install & MCP-only install

claude plugin marketplace add fastslack/mtw-e2e-runner
claude plugin install e2e-runner@matware

This gives Claude 17 MCP tools, a workflow skill, 4 slash commands (/e2e-runner:run, /e2e-runner:create-test, /e2e-runner:verify-issue, /e2e-runner:capture), and 3 specialized agents (test-analyzer, test-creator, test-improver).

MCP-only install (tools only, no skill/commands/agents):

claude mcp add --transport stdio --scope user e2e-runner \
  -- npx -y -p @matware/e2e-runner e2e-runner-mcp

OpenCode

cp node_modules/@matware/e2e-runner/opencode.json ./
mkdir -p .opencode && cp -r node_modules/@matware/e2e-runner/.opencode/* .opencode/

See OPENCODE.md for details.

The 17 MCP tools

Tool	Description
`e2e_run`	Run tests (all, by suite, or by file)
`e2e_list`	List available test suites
`e2e_create_test`	Create a new test JSON file
`e2e_create_module`	Create a reusable module
`e2e_pool_status`	Check Chrome pool health
`e2e_app_pool_status`	Inspect the app environment pool (forks, ports, drivers)
`e2e_screenshot`	Retrieve a screenshot by hash
`e2e_capture`	Capture screenshot of any URL
`e2e_analyze`	Extract page structure (interactive elements, forms, headings) and emit test scaffolds
`e2e_dashboard_start`	Start web dashboard
`e2e_dashboard_stop`	Stop web dashboard
`e2e_dashboard_restart`	Restart the dashboard (new project dir/port, clear stale sessions)
`e2e_issue`	Fetch issue and generate tests
`e2e_network_logs`	Query network logs for a run
`e2e_learnings`	Query stability insights
`e2e_vars`	Manage SQLite-backed `{{var.KEY}}` project variables
`e2e_neo4j`	Manage Neo4j knowledge graph

Pool start/stop are CLI-only — not exposed via MCP.

Visual verification — describe the page, AI judges it

Describe what the page should look like — AI judges pass/fail from screenshots:

{
  "name": "dashboard-loads",
  "expect": "Patient list with at least 3 rows, no error messages, sidebar with navigation links",
  "actions": [
    { "type": "goto", "value": "/dashboard" },
    { "type": "wait", "selector": ".patient-list" }
  ]
}

After test actions complete, the runner auto-captures a verification screenshot. The MCP response includes the screenshot hash — Claude Code retrieves it and visually verifies against your expect description. No API key required.

Issue-to-test — turn a bug report into a runnable test

Turn GitHub and GitLab issues into executable E2E tests. Paste an issue URL and get runnable tests — automatically.

How it works:

Fetch — Pulls issue details (title, body, labels) via gh or glab CLI
Generate — AI creates JSON test actions based on the issue description
Run — Optionally executes the tests immediately to verify if a bug is reproducible

# Fetch and display
e2e-runner issue https://github.com/owner/repo/issues/42

# Generate a test file via Claude API
e2e-runner issue https://github.com/owner/repo/issues/42 --generate

# Generate + run + report
e2e-runner issue https://github.com/owner/repo/issues/42 --verify
# -> "BUG CONFIRMED" or "NOT REPRODUCIBLE"

In Claude Code, just ask:

"Fetch issue #42 and create E2E tests for it"

Bug verification logic: Generated tests assert the correct behavior. Test failure = bug confirmed. All tests pass = not reproducible.

Auth: GitHub requires gh CLI, GitLab requires glab CLI. Self-hosted GitLab is supported.

📊 Dashboard & insights

e2e-runner dashboard                  # Start on default port 8484
e2e-runner dashboard --port 9090      # Custom port

Web dashboard tour — live view, history, gallery, pool status

Live execution — monitor tests in real-time with step-by-step progress, durations, and active worker count.

Test suites — browse all suites across projects. Run a single suite or all tests with one click.

Run history — track pass-rate trends with the built-in chart. Click any row to expand full detail.

Run detail — PASS/FAIL badges, screenshot thumbnails with copyable hashes (ss:77c28b5a), formatted console errors, and network request logs.

Screenshot gallery — browse all captured screenshots with hash search (action, error, and verification captures).

Pool status — Chrome pool health: available slots, running sessions, memory pressure.

Learning system — flaky tests, unstable selectors, slow APIs

The runner learns from every test run — building knowledge about your test suite over time. Query insights via the e2e_learnings MCP tool:

Query	Returns
`summary`	Full health overview: pass rate, flaky tests, unstable selectors, API issues
`flaky`	Tests that pass only after retries
`selectors`	CSS selectors with high failure rates
`pages`	Pages with console errors, network failures, load time issues
`apis`	API endpoints with error rates and latency (auto-normalized: UUIDs, hashes, IDs)
`errors`	Most frequent error patterns, categorized
`trends`	Pass rate over time (auto-switches to hourly when all data is from one day)
`test:<name>`	Drill-down history for a specific test
`page:<path>`	Drill-down history for a specific page
`selector:<value>`	Drill-down history for a specific selector

Storage & export:

SQLite (~/.e2e-runner/dashboard.db) — default, zero setup
Neo4j knowledge graph — optional, for relationship-based analysis. Manage via e2e_neo4j MCP tool or docker compose
Markdown report (e2e/learnings.md) — auto-generated after each run

Test narration: Each test run generates a human-readable narrative of what happened step by step, visible in the CLI output and the dashboard.

Network error handling — assertions, global flag, full logging

Explicit assertion — place assert_no_network_errors after critical page loads:

{ "type": "goto", "value": "/dashboard" },
{ "type": "wait", "selector": ".loaded" },
{ "type": "assert_no_network_errors" }

Global flag — set failOnNetworkError: true to automatically fail any test with network errors:

e2e-runner run --all --fail-on-network-error

When disabled (default), the runner still collects and reports network errors — the MCP response includes a warning when tests pass but have network errors.

Full network logging — all XHR/fetch requests are captured with URL, method, status, duration, request/response headers, and response body (truncated at 50KB). Viewable in the dashboard with expandable request detail rows.

MCP drill-down flow:

1. e2e_run          → compact networkSummary + runDbId
2. e2e_network_logs(runDbId)                     → all requests (url, method, status, duration)
3. e2e_network_logs(runDbId, errorsOnly: true)   → only failed requests
4. e2e_network_logs(runDbId, includeHeaders: true) → with headers
5. e2e_network_logs(runDbId, includeBodies: true)  → full request/response bodies

The e2e_run response stays compact (~5KB) regardless of how many requests were captured. Use e2e_network_logs with the returned runDbId to drill into details on demand.

Screenshot capture — snapshot any URL on demand

Capture screenshots of any URL on demand — no test suite required:

e2e-runner capture https://example.com
e2e-runner capture https://example.com --full-page --selector ".loaded" --delay 2000

Via MCP, the e2e_capture tool supports authToken and authStorageKey for authenticated pages — it injects the token into localStorage before navigating.

Every screenshot gets a deterministic hash (ss:a3f2b1c9). Use e2e_screenshot to retrieve any screenshot by hash — it returns the image with metadata (test name, step, type).

🌐 Browser drivers

The runner can talk to multiple browser engines through different drivers. The default is auto — it probes each pool URL and picks the right driver per pool.

Driver	Engine	Detection probe	When to use
`browserless`	Real Chromium via browserless	`/pressure` returns JSON	Default. Production-grade JS execution, screencast, full Chrome behavior
`cdp`	Generic CDP-compatible (raw Chrome, etc.)	`/json/version` reachable	Fallback for any CDP server that isn't one of the others
`lightpanda`	Lightpanda (Zig)	`/json/version` Browser=lightpanda	~9× faster, ~16× less memory than headless Chrome — ideal for high-volume scrape-style tests
`obscura`	Obscura (Rust + V8)	`/json/version` Browser=obscura	~30 MB RAM footprint, built-in anti-detection (`--stealth`), stays close to real Chrome via Puppeteer
`steel`	Steel Browser	`/v1/sessions` returns JSON	Managed session lifecycle, REST API for orchestration

Pick a driver per test / force one per run

{
  "tests": [
    {
      "name": "checkout flow (heavy JS, real Chrome)",
      "driver": "browserless",
      "actions": [...]
    },
    {
      "name": "scrape product page (lightweight)",
      "driver": "obscura",
      "fallbackDriver": "cdp",
      "actions": [...]
    }
  ]
}

driver is optional. If set, only pools whose detected driver matches become candidates. fallbackDriver is explicit opt-in — without it, a missing target driver fails the test with a clear message. Pool busyness does not trigger fallback; the runner waits inside the filtered set.

Force a driver for a whole run (CLI overrides win over per-test fields — useful for A/B benchmarks):

e2e-runner run --all --driver obscura
e2e-runner run --all --driver obscura --fallback-driver cdp

Running each driver locally

# browserless (default) — managed by `pool start`
e2e-runner pool start

# Lightpanda — pool start uses templates/docker-compose-lightpanda.yml
e2e-runner pool start                 # with poolDriver: 'lightpanda' in config

# Obscura — install the binary and run it yourself
curl -LO https://github.com/h4ckf0r0day/obscura/releases/latest/download/obscura-x86_64-linux.tar.gz
tar xzf obscura-x86_64-linux.tar.gz
./obscura serve --port 9222 --stealth
# then point the runner at it: poolUrls: ['http://localhost:9222'], poolDriver: 'obscura'

⚙️ CLI, config & CI

CLI commands

# Run tests
e2e-runner run --all                  # All suites
e2e-runner run --suite auth           # Single suite
e2e-runner run --tests path/to.json   # Specific file
e2e-runner run --inline '<json>'      # Inline JSON

# Pool management (CLI only, not MCP)
e2e-runner pool start                 # Start Chrome container
e2e-runner pool stop                  # Stop Chrome container
e2e-runner pool status                # Check pool health

# Issue-to-test
e2e-runner issue <url>                # Fetch issue
e2e-runner issue <url> --generate     # Generate test via AI
e2e-runner issue <url> --verify       # Generate + run + report

# Dashboard
e2e-runner dashboard                  # Start web dashboard

# Other
e2e-runner list                       # List available suites
e2e-runner capture <url>              # On-demand screenshot
e2e-runner init                       # Scaffold project

CLI options

Flag	Default	Description
`--base-url <url>`	`http://host.docker.internal:3000`	Application base URL
`--pool-url <ws>`	`ws://localhost:3333`	Chrome pool WebSocket URL
`--concurrency <n>`	`3`	Parallel test workers
`--retries <n>`	`0`	Retry failed tests N times
`--action-retries <n>`	`0`	Retry failed actions N times
`--test-timeout <ms>`	`60000`	Per-test timeout
`--timeout <ms>`	`10000`	Default action timeout
`--output <format>`	`json`	Report: `json`, `junit`, `both`
`--env <name>`	`default`	Environment profile
`--fail-on-network-error`	`false`	Fail tests with network errors
`--project-name <name>`	dir name	Project display name
`--driver <name>`	(per-test)	Force pool driver for the run: `browserless`, `cdp`, `lightpanda`, `obscura`, `steel`
`--fallback-driver <name>`	none	Explicit fallback if no pool with `--driver` is reachable

Configuration — e2e.config.js & priority

Create e2e.config.js in your project root:

export default {
  baseUrl: 'http://host.docker.internal:3000',
  concurrency: 4,
  retries: 2,
  actionRetries: 1,
  testTimeout: 30000,
  outputFormat: 'both',
  failOnNetworkError: true,
  exclude: ['explore-*', 'debug-*'],

  hooks: {
    beforeEach: [{ type: 'goto', value: '/' }],
  },

  environments: {
    staging: { baseUrl: 'https://staging.example.com' },
    production: { baseUrl: 'https://example.com', concurrency: 5 },
  },
};

Config priority (highest wins):

CLI flags
Environment variables
Config file (e2e.config.js or e2e.config.json)
Defaults

When --env <name> is set, the matching profile overrides everything.

CI/CD — JUnit XML & GitHub Actions

e2e-runner run --all --output junit

jobs:
  e2e:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm ci
      - run: npx e2e-runner pool start
      - run: npx e2e-runner run --all --output junit
      - uses: mikepenz/action-junit-report@v4
        if: always()
        with:
          report_paths: e2e/screenshots/junit.xml

Programmatic API

import { createRunner } from '@matware/e2e-runner';

const runner = await createRunner({ baseUrl: 'http://localhost:3000' });

const report = await runner.runAll();
const report = await runner.runSuite('auth');
const report = await runner.runFile('e2e/tests/login.json');
const report = await runner.runTests([
  { name: 'quick-check', actions: [{ type: 'goto', value: '/' }] },
]);

Requirements

Node.js >= 20
Docker — only for Option 3 (the parallel Chrome pool). Options 1 & 2 don't need it.

License

Licensed under the Apache License, Version 2.0. See LICENSE for details.

How to install

Run in your terminal:

claude mcp add mtw-e2e-runner -- npx

Mtw E2e Runner

About

README

@matware/e2e-runner

🎬 Write a test by asking — then watch it run

📖 Contents

🚀 Install — it's tiny

Option 1 · Use the Chrome you already have — no Docker ⭐

Option 2 · Obscura — one tiny binary, no Docker

Option 3 · Docker pool — parallel, for CI & big suites

Write your first test

Updating

✨ What you get

✍️ Writing tests

🤖 AI integration

📊 Dashboard & insights

🌐 Browser drivers

⚙️ CLI, config & CI

Requirements

License

How to install

Related MCPs

Compare Mtw E2e Runner with

Playwright

Puppeteer

opentabs-dev/opentabs

robhunter/agentdeals

Command Palette

Mtw E2e Runner

About

README

@matware/e2e-runner

🎬 Write a test by asking — then watch it run

📖 Contents

🚀 Install — it's tiny

Option 1 · Use the Chrome you already have — no Docker ⭐

Option 2 · Obscura — one tiny binary, no Docker

Option 3 · Docker pool — parallel, for CI & big suites

Write your first test

Updating

✨ What you get

✍️ Writing tests

🤖 AI integration

📊 Dashboard & insights

🌐 Browser drivers

⚙️ CLI, config & CI

Requirements

License

How to install

Related MCPs

Compare Mtw E2e Runner with

Playwright

Puppeteer

opentabs-dev/opentabs

robhunter/agentdeals