All notable changes to this project will be documented in this file.

If you have questions, please contact us by emailing our engineering team at apisupport@emsibg.com.

June 2026

1.13.5 (Jun 18)

Added

Introduced the 2026.3 dataset.

Changed

Updated the default datarun from 2026.2 to 2026.3.
Removed datarun 2025.2

May 2026

1.13.4 (May 5)

Added

Introduced the 2026.2 dataset.

Changed

Updated the default datarun from 2026.1 to 2026.2.
Removed datarun 2025.1

January 2026

1.13.3 (January 22)

Added

Introduced the 2026.1 dataset.

Changed

Updated the default datarun from 2025.4 to 2026.1.

September 2025

1.13.2 (September 30)

Added

Introduced the 2025.4 dataset.

Changed

Updated the default datarun from 2025.3 to 2025.4.
Removed datarun 2024.4.

June 2025

1.13.1 (June 25)

Added

Introduced the 2025.3 dataset.

Changed

Updated the default datarun from 2025.2 to 2025.3.

June 2025

1.13.0 (June 10)

Added

Default datarun set to 2025.2.

June 2025

1.12.1 (June 3)

Added

Introduced the 2025.2 dataset.

Removed

Removed the 2024.3 dataset.

March 2025

1.12.0 (March 11)

Changed

Updated the default datarun from 2024.3 to 2025.1.

February 2025

1.11.1 (February 6)

Changed

Updated the dataruns field in the /meta response to include 2025.1.

Added

Introduced the 2025.1 dataset.

October 2024

1.11.0 (October 18)

Added

Added support for the datarun query parameter to switch between dataruns.
Added the dataruns field in the /meta response, listing available dataruns.
Introduced the 2024.4 dataset.

Changed

Updated the dataruns field in the /meta response to include 2024.4.
Default datarun set to 2024.3.

July 2024

1.10.0 (July 3)

Changed

Data updated, using 2024.3 areas.

Added

cdp level data was added.

April 2024

1.9.12 (April 29)

Changed

Data updated, using 2024.2 areas.

February 2024

1.9.11 (February 12)

Changed

Data updated, using 2024.1 areas.

November 2023

1.9.10 (November 20)

Changed

Data updated, using 2023.4 areas.

July 2023

1.9.9 (July 26)

Changed

Data updated, using 2023.3 areas.

May 2023

1.9.8 (May 9)

Changed

Data updated, using 2023.2 areas.

March 2023

1.9.7 (March 24)

Refactored

Updated back-end infrastructure.

January 2023

1.9.6 (January 24)

Changed

Data updated, using 2023.1 areas.

November 2022

1.9.5 (November 14)

Changed

Data updated, using 2022.4 areas.

August 2022

1.9.4 (August 10)

Changed

Data updated, using 2022.3 areas.

April 2022

1.9.3 (April 26)

Changed

Data updated, using 2022.2 areas.

January 2022

1.9.2 (January 24)

Changed

Data updated, using 2022.1 areas.

April 2021

1.9.1 (April 13)

Fixed

Converted ACS no data estimates to null.

March 2021

1.9.0 (March 15)

Added

10 new metrics (see /meta/metrics for more detail):
- adult_civilian_population
- carpooling
- civilian_noninstitutionalized_population
- cohabiting_couple_households
- cohabiting_couple_households_pct
- commute_other_means
- driving_alone
- public_transport
- walking
- workers_16_and_over

Changed

Updated Census data version to 2019.

Fixed

Derived percentage metrics now correctly represent national percentages as reported by ACS. Derived metrics only occur when an Emsi Area is not represented in the latest version of ACS.

Removed

4 removed metrics:
- families
- families_pct
- non_family_households
- non_family_households_pct

December 2020

1.8.0 (December 4)

Added

zip level data was added.
tract level data was added.

Changed

The ACS data now uses Emsi geographies.

September 2020

1.7.0 (September 25)

Added

10 new metrics (see /meta/metrics for more detail):
- carpooling_pct
- commute_other_means_pct
- driving_alone_pct
- employed_with_health_insurance
- median_house_value
- median_monthly_rent
- non_english_households_pop
- population
- public_transport_pct
- walking_pct

Refactored

Restructured back-end data structures to improve API resource allocation and performance.

June 2020

1.6.0 (June 15)

Fixed

The following ACS estimate values are now returned as null:
- -888888888 – estimate is not applicable or not available
- -999999999 – the number of sample cases is too small

January 2020

1.5.0 (January 30)

Changed

Updated Census data version to 2018.

Fixed

Replaced fips with county in API documentation as fips is not a valid level.

March 2019

1.4.2 (March 20)

Changed

Upgraded proxy web server.

1.4.1 (March 4)

Changed

Minor performance improvements.

February 2019

1.4.0 (February 26)

Changed

ACS estimate values of -666666666, denoting insufficient sample observations for a given region, are now returned as null.

1.3.0 (February 14)

Changed

Clarified wording in API documentation.
Changed the nonfamily_households and nonfamily_households_pct metrics to non_family_households and non_family_households_pct respectively.
Updated titles/descriptions for the following metrics: foreign_born_population, foreign_born_population_pct, disabled_population, households, non_family_households, and non_family_households_pct.

1.2.0 (February 12)

Changed

median_household_income and per_capita_income metric now use the new money format.
Updated descriptions for vacant_housing_units, homeowner_vacancy_rate, and rental_vacancy_rate.
Updated homeowner_vacancy_rate and rental_vacancy_rate to use the percent format.
Changed metric name of veteran_status to veterans.
All metric titles are now in title case (the capitalization of the first letter of each word).
Updated attribution title and body to include "American Community Survey" instead of just "ACS".

Added

New money metric format.
New veterans_pct, foreign_born_population_pct, and disabled_population_pct metrics.

Fixed

Updated veterans, foreign_born_population, and disabled_population to use the correct ACS variables.
Corrected nonfamily_households and nonfamily_households_pct metrics, they no longer overwrite one another.

1.1.0 (February 5)

Changed

In the /meta/metrics and /meta/metrics/{metric} endpoints the following field names changed to be more accurate to what they represent:
- acs_census_tables changed to acs_census_variables
- acs_census_table_links changed to acs_census_variable_links

Added

31 new metrics (see /meta/metrics for more detail):
- median_age
- per_capita_income
- poverty_level_pct
- children_poverty_level_pct
- seniors_poverty_level_pct
- mean_commute_time
- remote_workers
- remote_workers_pct
- housing_units
- occupied_housing_units
- occupied_housing_units_pct
- vacant_housing_units
- vacant_housing_units_pct
- homeowner_vacancy_rate
- rental_vacancy_rate
- veteran_status
- foreign_born_population
- disabled_population
- avg_household_size
- households
- families
- families_pct
- avg_family_size
- married_family_households
- married_family_households_pct
- male_householder_family_households
- male_householder_family_households_pct
- female_householder_family_households
- female_householder_family_households_pct
- nonfamily_households
- nonfamily_households

January 2019

1.0.0 (January 28)

Added

Start a changelog to document updates to the API.

Changelog