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.
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.
Posted February 22, 2021
We have added a new field,
hospitalizedDischarged for several states. More states will be added as we get data:
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.
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
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:
outcomes.hospitalized.total: Cumulative hospitalized/Ever hospitalized
These features were built against an RFP that got considerable public and private feedback from select API users.
No. We will never take offline or remove features from the v1 API. We may still change deprecated fields as we always have.
It is available now, but all URLs are prefixed with
/v2beta. We will take it out of beta on February 15.
Feel free to contact us with any questions or concerns (select “API in the dropdown) about the new API.
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
As of January 27, 2021, these states will have a
null value for
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
Posted December 14, 2020
On December 28, we will be deprecating the following fields in the States metadata endpoints:
Posted November 18, 2020
On December 2, 2020 we will officially deprecate the
recovered field in our national endpoints (i.e.
As of January 8, 2021, this field returns
Posted November 4, 2020
The following fields in our API have been deprecated for several months, and will start returning
null on November 16
total- Will return zero, use
posNeg- Will return zero, use
checkTimeEt- Will return
dateModified- Will return
dateChecked- Will return
hospitalizedIncrease- Will return
hash- Will return null.
hash- Will return null
hospitalizedIncrease- Will return
lastModified- Will return
dateChecked- Will return
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.
Posted September 29, 2020
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
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
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.
Posted September 2, 2020
We are adding two new fields to the states info endpoints (
covidTrackingProjectPreferredTotalTestField- Locator field that explains which API fields The COVID Tracking Project prefers for each state’s “New tests” chart and on the state’s history page on our website. Selects from the following options in order of priority: totalTestEncountersViral, totalTestsViral, totalTestsPeopleViral, or—where those units are all missing a sufficient time series—totalTestResults.
covidTrackingProjectPreferredTotalTestUnits- Label indicating which units The COVID Tracking Project prefers for each state’s “New tests” chart and on the state’s history page on our website. Selects from the following options in order of priority: test encounters, specimens, people, or—where those units are all missing a sufficient time series—negatives plus positives.
Posted August 25, 2020
We have updated our API page to align all field definitions with those in our data definitions page.
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:
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.
|Old URL||New URL|
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.
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!