From Cypress

Cypress specs chain commands on cy. Momentic tests are YAML steps that a runner executes with built-in waiting and AI assertion. The porting unit is the user flow, not the command chain. A coding agent with the MCP server and coding agent skills ports a spec file in one pass.

Before and after

A representative Cypress spec:

checkout.cy.js

describe("checkout", () => {
  beforeEach(() => {
    cy.session("user", () => cy.loginByApi());
    cy.visit("/products/42");
    cy.intercept("GET", "/api/cart", { fixture: "cart.json" }).as("cart");
  });

  it("lets a guest buy a blanket", () => {
    cy.get('[data-testid="add-to-cart"]').click();
    cy.get('[data-testid="cart-icon"]').click();
    cy.wait("@cart");
    cy.contains("Gravity Blanket").should("be.visible");
    cy.findByRole("button", { name: "Checkout" }).click();
    cy.get("#email").type("jeff@example.com");
    cy.findByRole("button", { name: "Place order" }).click();
    cy.location("pathname").should("match", /\/orders\/\w+/);
    cy.contains("Order confirmed").should("be.visible");
  });
});

The same test in Momentic:

checkout.test.yaml

fileType: momentic/test/v2
id: guest-checkout
url: https://shop.example.com/products/42
labels: [checkout]
before:
  - module: ../modules/log-in.module.yaml # your cy.session equivalent
steps:
  - mock:
      substring: /api/cart
      method: get
      responseGenerator: |-
        return new Response(
          JSON.stringify([{ id: 1, title: "Gravity Blanket", qty: 1 }]),
          { status: 200, headers: { "content-type": "application/json" } })
  - click: Add to cart
  - click: the cart icon
  - assert: The cart lists "Gravity Blanket"
  - click: Checkout
  - type:
      text: jeff@example.com
      into: the Email field
  - click: Place order
  - waitForUrl:
      regex: /\/orders\/\w+/
  - assert: An order confirmation is visible

API mapping

Cypress	Momentic
`cy.visit(url)`	`navigate: <url>` (or the test’s top-level `url`)
`cy.get(sel).click()`	`click: <natural language>` or `click: { css: sel }`
`cy.contains(text)`	`assert: "<text> is visible"` or `checkPageContains`
`.type(value)`	`type: { text: ..., into: <field> }`
`.should("be.visible")` / assertions	`checkElementVisible` / `assert:`
`cy.location().should(match)`	`waitForUrl: { regex }`
`cy.intercept(...)`	`mock` (`substring`, `glob`, `regex`, `domain`)
`cy.wait("@alias")`	`registerRequestListener` + `awaitListener` to capture the payload; nothing when only ordering matters
`cy.wait(ms)`	`wait: <ms>` (prefer an `assert` with `timeout` when a signal exists)
`cy.getCookie` / `cy.setCookie`	`cookie: name=value` sets one cookie; browser `javascript` reads them (HttpOnly stays unreadable)
`cy.clearLocalStorage`	browser `javascript` calling `localStorage.clear()`; `localStorage` step only writes keys
`cy.go("back")` / `"forward"`	`goBack` / `goForward`
`cy.select(...)`	`select` step, or `click` the option
`cy.on("window:alert"/"confirm")`	`dialog: ACCEPT` or `DISMISS`, placed before the step that raises it
`cy.screenshot()`	automatic per-step screenshots; `assertVisually` for visual checks
`cy.fixture("cart.json")`	inline the JSON into `mock.responseGenerator`, or read files with `child_process` in a `javascript` step
`cy.request(...)`	`javascript` step (`fetch` is available) or `graphqlRequest`
`cy.session(...)`	`authLoad`/`authSave` steps, or a login module in `before:`
`Cypress.Commands.add(...)`	module
`cy.viewport(...)`	no equivalent; the runner controls the viewport
`it.skip` / `it.only`	`disabled: true` on the test, `--filter`/`--labels` at run time
`cypress.config.ts` `baseUrl`	`environments[].baseUrl`
`Cypress.env(...)`	`env.<NAME>` variables from `environments[].envVariables`
Retry-ability of `cy.*`	steps poll targets and conditions until their `timeout`; `retries:` reruns a failed step
`cy.origin(...)` for cross-origin flows	unnecessary; steps work across origins and `newTab`

Fixture and plugin mapping

Cypress	Momentic
`cypress/fixtures/*.json`	Keep the files where they are. Read them with `child_process` (for example `execSync("cat cypress/fixtures/cart.json")`) in a `javascript` step and `setVariable`/`saveAs` the parsed value, or inline the payload into a `mock` response.
`cypress/support/commands.js`	Each `Cypress.Commands.add` becomes a `*.module.yaml`. Parameters map to module `parameters`; call sites become `module:` steps with `inputs`.
`cypress.config.ts` plugins / `task()`	A `javascript` step runs Node in a sandbox. Database seeding, email inboxes, and file work port directly. See JavaScript integration.
`e2e` folder structure	Keep the same directories; Momentic discovers `*.test.yaml` through the `include` globs in `momentic.config.yaml`.
Component testing	No equivalent. Momentic is end-to-end only; keep Cypress or Vitest for component tests if you use them.

What does not map

The command queue and cy object. Steps are data, not a chained API. Anything you built on cy.wrap, subjects, or custom queue manipulation needs a javascript step.
cy.spy/cy.stub on window functions. There is no step for spying on app internals. mock covers network interception; reach for javascript with environment: browser for the rest.
cypress-real-events and raw Chrome DevTools Protocol (CDP). Momentic abstracts the driver. Device trust and CDP-specific tricks have no direct equivalent.
Time-travel snapshots UI. The local editor and run viewer show the same evidence (video, per-step screenshots, DOM state) but it is not a scrubbable command log.

Incremental strategy

Install momentic next to Cypress in the same repo: npm install -D momentic plus a minimal momentic.config.yaml. The two tools do not share files or ports.
Port cy.session/login first as a module or authLoad file; every other port depends on it.
Port the specs that hurt the most to maintain: the ones with the most selector churn. Label them migrated and run them with --labels migrated.
Run both suites in CI. Keep Cypress gating until the Momentic suite covers the same critical paths.
Retire specs one at a time after several consecutive passing Momentic runs. Remove @cypress/* dependencies and the cypress folder last.

Porting at scale with a coding agent

Point your coding agent at the spec files and the momentic-test skill. A prompt that works well:

Port cypress/e2e/checkout.cy.js to Momentic tests under tests/checkout/.
Read the momentic-test skill first. Convert each it() to a *.test.yaml, each
custom command to a *.module.yaml under tests/modules/, and each cy.intercept
to a mock step. Reuse cypress/fixtures JSON files as-is. Run each ported test
with npx momentic run <file>.

Overview

Migrate to Momentic

Frameworks

Use cases

Triage

AI actions

Authentication

Page interactions

Test data & variants

Visual testing

Reporting

Upgrading

Before and after

API mapping

Fixture and plugin mapping

What does not map

Incremental strategy

Porting at scale with a coding agent

​Before and after

​API mapping

​Fixture and plugin mapping

​What does not map

​Incremental strategy

​Porting at scale with a coding agent

​Related

Before and after

API mapping

Fixture and plugin mapping

What does not map

Incremental strategy

Porting at scale with a coding agent

Related