Announcing the API

Covid Act Now (CAN) is a non-profit organization of technologists, epidemiologists, and medical professionals working to model how COVID-19 will spread in each U.S. state and county. 

We published the first version of our model on March 20. Since then, 10+ million Americans have viewed the model and we’ve engaged with dozens of government officials, including the U.S. Military and White House, to assist with response planning.

Today, we are launching an API to make our data programmatically available to everyone.

Our API exposes:

  • Reported Data: State and county level data for confirmed cases, deaths, and hospital bed capacity. The data is collected from a number of sources, including The New York Times, and is updated daily.
  • Forward Projections: State and county level projections for hospitalizations and deaths based on several possible interventions. This data is generated from our model.

By launching a public API, we are making the data that powers available to anyone, free of charge, under the Creative Commons 4.0 license. The data is updated daily around midnight U.S. Pacific Time, and is available in both JSON and CSV format.

You can view the documentation on GitHub.

By making this data available, we are hoping it will be a helpful input into COVID efforts such as response planning, reopening initiatives, data visualization, and the creation of new tools.


Since Covid Act Now launched on March 20, our team has spent significant time refining our model. It is originally based on a traditional SEIR model by Dr. Alison Hill at Harvard, and now Dr. Rebecca Katz and her team at the Georgetown Center for Global Health Science and Security audits our work. In the past few weeks we’ve made several improvements, including adding hospitalization and severity rates, data sources, and inference projections.

Going forward, our organization will be focusing on providing data to leaders to inform their decisions around reopening safely. 

Our work is being done in the open, and you can find our model open-sourced on GitHub.

Using the API

To get data from our API, you’ll need to construct a URL with the state or county, the intervention type, and append .json or .csv. For example: + [ STATE CODE (CA, PA, NV) ]
+ [ .INTERVENTION_OPTION ] + [ .timeseries.json ]

JSON objects can be easily manipulated with code, while CSV (comma separated values) can be easily imported into Google Sheets or Excel.

The intervention choices are:

API ParameterIntervention TypeR Assumptions
WEAK_INTERVENTIONSocial Distancing1.7
STRONG_INTERVENTIONShelter in Place1.1 for 4 weeks, 1.0 for 4 weeks, 0.8 for 4 weeks.
OBSERVED_INTERVENTIONA dynamic forecast based on the observed data in a given U.S. state

Two notes on interventions:

  • OBERSERVED_INTERVENTION infers an R(t) value from recent cases, hospitalizations, and deaths in each state.
  • To see more details on each intervention and sources for our R assumptions, please see our model references and assumptions.

For example, this link returns an aggregated list of how COVID will spread in every U.S. State based on observed data, in CSV format:

And this is Dakota County, Minnesota’s data for how COVID would spread if it reopened everything tomorrow, in JSON format. (Note that we’re constructing the URL with the FIPS code for the county.)

Open this link in your browser now to see the data:

Hopefully these examples give you a taste of how to use the API. For all the details, see the documentation on GitHub.

In the future, we intend to make more data available, including:

  • Additional file formats like shapefiles for GIS systems.
  • Integrations with data visualization products, like Tableau.

Please Play Around!

In order to accelerate decision making, safely re-open the country, and, ultimately, save lives, a massive, unprecedented collaboration across government, business, and the general public is needed. 

We hope this data plays a small part in that collaboration, and we’re excited to see how it is used, visualized, integrated, and transformed to make a difference.

To learn more about Covid Act Now, visit our about page. For more information please reach out on our contact page or by email at

Happy coding!

Thanks to Addy Osmani, Chad Arimura, Ilya Voldarsky, Josh Dzielak, Max Lynch, Paul Irish, and Steve Wilmott for reading drafts of this post and giving feedback on the API.

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