Configuration

The server needs a single credential: a Google PageSpeed Insights API key. It can be provided in three ways.

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Credential

GOOGLE_PSI_API_KEY

Your PageSpeed Insights API key from the Google Cloud Console.

Method	Example
Environment variable	GOOGLE_PSI_API_KEY=AIzaXXX
CLI argument	--api-key AIzaXXX
.env file	GOOGLE_PSI_API_KEY=AIzaXXX

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Resolution Order

The server resolves the API key using this priority (highest to lowest):

1. CLI argument (--api-key)
2. Environment variable (GOOGLE_PSI_API_KEY in process env or tool config env block)
3. .env file in the working directory

The first source that provides a non-empty value is used. If none are present, the server exits with an error at startup.

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No Additional Configuration

Unlike OAuth2-based servers, there is no token refresh, no service account JSON, and no billing account to configure. The PSI API key is the only credential.

• Free quota: 25,000 requests per day per Google Cloud project -- far more than any interactive use requires.
• Billing: Not required. Enable the API on a free-tier project and it works.
• Restricting the key: In Google Cloud Console → Credentials, restrict the key to the PageSpeed Insights API only to limit exposure.