Tracewright

A regression test automation agent for Playwright

(16x speed)

• Attempts to execute BDD-like (behavior-driven development) tasks for websites
• Saves functional Playwright code, screenshots, and interactable HTML elements for each step
• Provides Playwright locator hooks to help make LLM interactions be more efficient
• Reenforcement loop for errors that occur during steps to encourage recovery

Installation

Within any Playwright project.

npm install @withmantle/tracewright

Usage

example.spec.ts

import test from "@playwright/test"
import tracewright from 'tracewright';

test("Youtube", async ({ page }) => {
  await page.goto("https://youtube.com");

  await tracewright(page, {
    script: `- Search for "boston dynamics do you love me"
- Open the second video
- Expand the video description
- Done`,
  });
});

Models

Authentication

VertexAI

gcloud auth application-default login
export GOOGLE_CLOUD_LOCATION=<location>
export GOOGLE_CLOUD_PROJECT=<name>

or Gemini Studio

export GEMINI_API_KEY=<api key>

Model Selection

The default is but this can be overridden with the GEMINI_MODEL environment variable.

ex.

export GEMINI_MODEL=gemini-2.5-pro

Why build this tool?

Workflow Empowerment - There are a lot of computer-use tools out there but we wanted something to plug directly into our workflow when working with Playwright. Specifically, the ability to use this agent within the Playwright test runner and alongside vanilla Playwright code has improved productivity.

Outputs for Agentic Flows - The output artifacts have a number of useful downstream use cases. Use cases like autogenerating Help Desk articles or generating Marketing videos are being explores. Really excited to hear what the community is coming up with, please share to inspire others!

Flexibility - Having the tool written in Typescript and support for Playwright mechanisms into the flow allows you to customize the experience to adjust the different nuances of all the websites out there. If the HTML parser or page waiting logic isn't working for you, you can adjust in realtime and hopefully submit a PR!

Contributing

Contributions are welcome! Please submit a PR or open an issue.

License

Apache 2.0

About Mantle

The team at Mantle is building modern solutions for managing private assets: from Cap Tables to Capital Calls. Mantle's equity management platform is a founder-friendly platform built from the ground-up to manage your startup's cap table. Our institutional LP solution unlocks real-time investment intelligence via automated, AI-powered workflows so LPs can make faster, data-driven decisions.