Mercury Retrograde API

This API serves JSON over HTTPs. It allows you to determine whether Mercury is in retrograde for a given date.

Why Should I Care?

Mercury Retrograde can really suck. I experience communication breakdowns frequently when Mercury is in retrograde. Maybe you do too. Click here to learn more about it.

How Do I Use It?

Basic Example

At the most basic level, you just need to make a GET request to the API. No auth, no body needed.

		> curl


The only available option is a 'date' parameter in the GET request. It should contain a date in the YYYY-MM-DD format.

		> curl

		> curl

JavaScript Example

This API is CORS enabled, meaning you can call it directly from a browser on any website.

		.then(res => res.json())
		.then(data => data.is_retrograde)
		.then(isRetrograde => {
    			// the isRetrograde will be true/false
    			alert(isRetrograde ? 'YES' : 'NO')

What Does This Cost?

It's free (really)! This API is used in production at Gingr. Over the years this API has been used in smart homes, other astrology websites, and many other things. I plan on hosting this API for many years to come, free of charge.

How Reliable Is This API?

This service has been online since 2015. In mid-2022, hosting was moved to The API is now served over an anycast network in 5+ geographically distinct regions with automatic failover.

I have a question.

Email me here.