When you run npx magnitude init, a magnitude.config.ts will be generated for you. By default it looks something like:

import { type MagnitudeConfig } from 'magnitude-test';

export default {
    url: "http://localhost:5173"
} satisfies MagnitudeConfig;

url is the default URL that all test cases will use if not specified.

However, there’s a lot more you can customize to get Magnitude working exactly as you want.

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Customizing Planner LLM

You can pass a provider and options to planner in order to configure the planner LLM, for example:

import { type MagnitudeConfig } from 'magnitude-test';

export default {
    url: "http://localhost:5173",
    planner: {
        provider: 'openai-generic',
        options: {
            baseUrl: "https://openrouter.ai/api/v1",
            apiKey: process.env.OPENROUTER_API_KEY,
            model: "google/gemini-2.5-pro-preview-03-25"
        }
    }
} satisfies MagnitudeConfig;

The planner LLM should be a strong general purpose multi-modal model. We recommend Gemini 2.5 Pro or Claude Sonnet 3.7.

For instructions on configuring LLMs with various providers, see LLM Configuration.

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Browser Options

You can customize options to pass to each Playwright browser context that gets created while running Magnitude tests.

Common options you may want to customize might be viewport or even recordVideo to capture videos of tests. For example:

import { type MagnitudeConfig } from 'magnitude-test';

export default {
    url: "http://localhost:5173",
    browser: {
        contextOptions: {
            viewport: { width: 800, height: 600 },
            recordVideo: {
                dir: './videos/',
                size: { width: 800, height: 600 }
            }
        }
    }
} satisfies MagnitudeConfig;

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Telemetry Opt-Out

By default Magnitude collects basic anonymized telemetry when you run a test, such as the duration of the test and number of tokens used.

To opt out of telemetry:

import { type MagnitudeConfig } from 'magnitude-test';

export default {
    url: "http://localhost:5173",
    telemetry: false
} satisfies MagnitudeConfig;