A static history of our API changes.

View the Project on GitHub COVID19Tracking/apichanges

COVID Tracking Project API Changelog


The COVID Tracking Project (CTP) hosted a data API with numbers for COVID-19 testing, outcomes, and hospitalization. This file includes publicly announced changes to the data API. The changelog was hosted and donated by Headway, and exported to this single markdown-formatted file by CTP staff.

Changelog entries

Ending support for CORS requests May 1, 2021

Posted April 28, 2021

As announced in February, the COVID Tracking Project’s API will be winding down in May. The first step in this process will be disabling support for CORS and removing redirects for our old services.

CORS Support enabled many developers to quickly build apps on our infrastructure without servers. However, a handful of poorly-built applications take up the bulk of our traffic, and they are all using CORS. We suggest caching our data within your own application.

New field: hospitalizedDischarged

Posted February 22, 2021

We have added a new field, hospitalizedDischarged for several states. More states will be added as we get data:

It’s Time: The COVID Tracking Project Will Soon Come to an End

Posted February 3, 2021

After a year of collecting, analyzing, and interpreting COVID-19 data for the United States, we’re ending our data compilation work in early March. The existing API will continue to work until May 2021, but will only include data up to March 7, 2021.

Deprecating state grades

Posted January 28, 2021

As part of a move to a new assessment process, we are officially deprecating the field dataQualityGrade from our state endpoints. The new state assessment data will be available by February 5 from our data downloads page.

On February 15, we will null out the dataQualityGrade field.

Announcing Version 2 of our API

Posted January 25, 2021

As the COVID Tracking Project approaches our first year, we have been learning-while-doing with building our API. Our API powers thousand of applications, with millions of users per month, and is core to our mission to provide the most accurate and timely data about COVID in the US to a wide audience.

Our current API is a flat, CSV-file like endpoint, with very little flexibility to add new fields or remove old deprecated ones. Because it was so quickly adopted, we were unable to change these fields around without breaking applications.

Today, we are announcing a beta of version 2 of our API with the following features:

These features were built against an RFP that got considerable public and private feedback from select API users.

Will the “v1” API change or go down?

No. We will never take offline or remove features from the v1 API. We may still change deprecated fields as we always have.

When will the v2 API be available?

It is available now, but all URLs are prefixed with /v2beta. We will take it out of beta on February 15.

How can I provide feedback?

Feel free to contact us with any questions or concerns (select “API in the dropdown) about the new API.

Removing negative test results from various states

Posted January 12, 2021

We are removing negatives that were created from mixed units (specimens minus cases or test encounters minus cases) for states that are using explicit totals in totalTestResults.

As of January 27, 2021, these states will have a null value for negative.

National recovered field is now deprecated

Posted January 8, 2021

Per our announcement on November 18, 2020 the national recovered field in the US endpoints is now deprecated and all US recovered values are now null.

Deprecation of state URLs

Posted December 14, 2020

On December 28, we will be deprecating the following fields in the States metadata endpoints:

Deprecation of national recovered data

Posted November 18, 2020

On December 2, 2020 we will officially deprecate the recovered field in our national endpoints (i.e. https://api.covidtracking.com/v1/us/daily.json).

As of January 8, 2021, this field returns null.

Learn more about why we are deprecating national recovered data.

Zeroing out of deprecated fields

Posted November 4, 2020

The following fields in our API have been deprecated for several months, and will start returning 0 or null on November 16

States daily


Deprecation of the public spreadsheet

Posted October 15, 2020

Since the COVID Tracking Project started in March, we have been collating and publishing our data in the form of a single Google Sheet. Our API and website both used that sheet to publish all our core dataset. As our data collection effort has matured, we have built new tools to improve our publishing process. To that end, all of our API and website data are now based on an improved publishing system that no longer uses Google sheets.

However, people have been using our public sheets to import our data in ways that were never intended. We only support pulling data through our API. Supporting users whose apps broke because we changed the public sheet has had a significant impact on our support teams.

We encourage anyone who is using the public sheet for importing data to switch to our API, or import the CSV files available from our download page. As of November 30, the sheet will be static and no longer get new rows or columns, and on December 24, it will be taken offline.

States: Deprecation of totalTestResultsSource

Posted September 29, 2020

The field totalTestResultsSource in the states/daily endpoints are now marked as deprecated, and will return null in two weeks.

Instead you should use the field totalTestResultsField in the states/info endpoint to find out what field is used to compute for totalTestResults.

States info & states daily: New total test results

Posted September 18, 2020

The states info endpoint now have a new totalTestResultsField field that indicates which field we are pulling from for the state’s totalTestResults value.

US daily: Total test results update

Posted September 17, 2020

Per our announcement on US total test results, the sources of totalTestResults are now updated to match our new standards.

While the field posNeg has been marked as deprecated since April, we are now returning 0 for that field.

New fields in States Info

Posted September 2, 2020

We are adding two new fields to the states info endpoints (/v1/states/info.json, and v1/states/info.csv):

API field description update

Posted August 25, 2020

We have updated our API page to align all field definitions with those in our data definitions page.

New Testing fields

Posted August 11, 2020

On August 14 2020, we will be publishing twelve new API fields in the states endpoints for antigen, PCR, and antibody testing:

Deprecation of old URLs

Posted August 6, 2020

We are officially deprecating the old API URLs that have been redirecting since April 2 to our current API paths. Users of these old URLs should update their apps before October 15, when these paths will start returning 404 errors.

/states/info.csv /v1/states/info.csv
/states/daily.csv /v1/states/daily.csv
/states.csv /v1/states/current.csv
/us.csv /v1/us/current.csv
/us/daily.csv /v1/us/daily.csv
/states/daily?state=:state&date=:date /v1/states/:state/:date.json
/statesdaily?state=:state&date=:date /v1/states/:state/:date.json
/states?state=:state /v1/states/:state/current.json
/us?date=date /v1/us/:date.json
/us/daily?date=date /v1/us/:date.json
/v1/us.json /v1/us/current.json
/v1/states.json /v1/states/current.json
/states/info /v1/states/info.json
/states/daily /v1/states/daily.json
/states.json /v1/states/current.json
/states /v1/states/current.json
/us /v1/us/current.json
/us.csv /v1/us/current.csv
/us/daily /v1/us/daily.json

New API domain name

Posted August 5, 2020

In order to serve the API more efficiently, we are moving the API service to a new domain: api.covidtracking.com. All of the relative URL paths like /v1/states/info.json are exactly the same and unchanged.

You can move your apps to the new domain now. On August 17, we will start redirecting all traffic from our old API endpoints at covidtracking.com/api to the new domain.

Comment on our proposal for a new API

Posted July 16, 2020

The COVID Tracking Project was founded in the early days of the COVID pandemic arriving in the US, and provided an API from day one. Since then, the data we collect has undergone many changes.

Because of this, we are working on a new version of the API. Please read the RFC and give a comment or thumbs up. We’d love to hear your feedback!