E2e

e2e: agentic end-to-end tests in TypeScript

e2e runs UI tests with agent goals and exact assertions. agent.act drives one goal; agent.assert, agent.waitFor, and agent.extract judge the screen. screen, app, browser, and expect make exact interactions and checks. The replay cache reruns verified actions and checks their recorded end state without a model call; agent judgments still run live. UI targets use @e2e-dev/web for browsers or @e2e-dev/mobile for iOS simulators, Android emulators, and connected phones. A test that takes only app can check an API with fetch and expect (topic writing-tests). Model sign-in commands are in setup.

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// e2e.config.ts
import type { E2EConfig } from 'e2e';
import { web } from '@e2e-dev/web';
import { gateway } from 'ai';

export default {
  targets: [
    {
      engine: web(),
      app: {
        url: 'http://127.0.0.1:3000',
        command: { executable: 'pnpm', args: ['dev'], log: '.e2e/logs/app.log' },
      },
    },
  ],
  // The model behind every agent.* step: an AI SDK instance; gateway() from 'ai' reads AI_GATEWAY_API_KEY or a Vercel OIDC token.
  agents: {
    default: {
      model: gateway('openai/gpt-6-luna-fast'),
      system: 'You are a thorough QA agent. Verify every outcome on screen.',
    },
  },
} satisfies E2EConfig;

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// tests/billing.e2e.ts
import { test } from '@e2e-dev/web';
import { expect } from 'e2e';

test('a member upgrades to Pro', async ({ app, agent, screen, browser }) => {
  await app.open('/settings/billing');
  await agent.act('upgrade the workspace to the Pro plan');
  await expect(screen.getByRole('status')).toContainText('Pro');
  await expect(browser).toHaveURL('/settings/billing');
});

Topics

Read the topic for the job before writing code. The files sit next to this one; the installed CLI prints the same text with npx e2e guide <topic> (e2e guide alone prints this page). For anything the topics do not cover, the full documentation ships in the docs/ directory of the installed e2e package (node_modules/e2e/docs in a single-package project); a link such as /reference/cli is docs/reference/cli.mdx. Complete projects for Vite, Next.js, Expo, and SwiftUI, each with its config, scripts, and a passing suite, are in https://github.com/tester-army/e2e/tree/main/examples.

Workflow

1. Look at what exists: e2e.config.ts or e2e.config.mts, the tests glob (default tests/**/*.e2e.ts), e2e in package.json. Nothing there: follow setup.
2. Learn the screens before writing a test: routes, labels, roles, button text. Semantic locators need the accessible names the app renders, so read the components, open the page with --headed, or drive the live app over the registered e2e mcp server (topic mcp): open_session, observe, and locate show exact names and check a locator before you write it.
3. Write tests/<feature>.e2e.ts. Drive the flow with agent.act, one goal per call, and pin each outcome right after with expect or agent.assert. Exact values go through screen: a sign-in form in a setup test, a field that must receive one specific string, a count that must be one number.
4. Run one file: npx e2e run tests/<feature>.e2e.ts. Agent steps need a model in the config and that provider's authentication (a saved subscription login, an API key); a local endpoint may need none. Tests without agent steps need no model.
5. Read the failure: the reporter prints the error code, message, and a code frame; .e2e/report.json has every step and artifact path. Fix the locator, the expectation, or the app. Never add a sleep.

Rules

• Run the CLI as npx e2e ... (or pnpm exec e2e ...).
• The config is export default { ... } satisfies E2EConfig with import type { E2EConfig } from 'e2e'. targets is required; a UI target names an engine and declares the app beside it: { engine: web(), app: { url, command } }. A tools-only target can omit the engine and set platform.
• Import test, describe, the hooks, expect, credentials, and secrets from e2e. A test that uses the browser fixture imports test, describe, and the hooks from @e2e-dev/web: the same runtime functions, typed with browser.
• Config and tests are ES modules whatever package.json sets as type.
• Locators resolve when used. Actions wait for readiness and expect retries assertions. Reads such as textContent() fail at once on zero matches and count() answers from the current screen; nothing waits for a value to change, so use a matcher when a value has to settle.
• A locator that matches two nodes fails with LOCATOR_AMBIGUOUS; narrow it (topic writing-tests).
• Secrets never appear in test code. Declare accounts under credentials and every other sensitive value under secrets in the config; resolve with credentials.user(name).password or secrets.get(name) (separate namespaces: secrets.get never returns a password), and hand the opaque Secret only to fill() or agent.act params.
• Agent instructions: one goal per act, the wording on screen, real values in params. Judge meaning, not phrasing: toContain('Pro'), not an exact sentence a model produced.
• Check each agent goal's outcome. A passing act with a recorded check can be cached and replayed without model calls (topic agent).
• Shape the agent for this app: context for vocabulary the screens use, system for how it works, tools for a test API, named personas under agents. When a step fails, tighten the goal first, then the context, then the agent.
• .e2e/ is output (report.json, artifacts/, cache/, logs/; the config's output moves the report and artifacts, never cache/ or the app's log). Read it, never edit it.

Feedback

When e2e itself gets in your way, tell the e2e team: a command or API that broke (bug), docs or this skill that misled you (docs), or a capability you needed and did not find (feature). Send it once per problem, after you worked around it or gave up, never for failures of the app under test.

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npx e2e feedback --type bug -m "<one or two sentences>" \
  --task "<what you were doing>" --expected "<...>" --actual "<error code and message>" \
  --approach "<what you tried>" --command "<e2e command>" --agent "<agent / model>"

Describe e2e's behavior only: never paste app content, page text, test files, URLs of private apps, or credentials. Secret-named environment variables and common token shapes are redacted, but do not rely on it. --dry-run prints what would be sent. Tell the user you sent it and give them the reference id it prints.