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Inflation (Historical)

Overview

The Inflation API lets you pull the monthly US Consumer Price Index (CPI) for one series at a time, from 1947 to today, with the month-over-month and year-over-year percent changes computed for you. We source the data directly from authoritative government sources. Values are index levels (1982-84 = 100); the changes are percentages. To get started, please create an account and grab your API key at financialdatasets.ai. You will use the API key to authenticate your API requests.

Coverage

Series

Six concepts, each seasonally adjusted (_sa) and not seasonally adjusted (_nsa): You can fetch this list, with each series’ first available month, with a free GET request to: https://api.financialdatasets.ai/macro/inflation/series/

Reading the fields

  • date is the reference month as its first day: 2026-08-01 is the August 2026 print, which is published in mid September. It is not the release date.
  • value is the published index level.
  • change_1m_pct is the percent change from the prior month and change_12m_pct from the same month a year earlier, both rounded to one decimal. The headline “inflation rate” is change_12m_pct of cpi_all_nsa; the headline monthly figure is change_1m_pct of cpi_all_sa.
  • A field is null when the comparison month was not published. October 2025 is null in every series because no October 2025 CPI was published, so the November 2025 1-month change and the October 2026 12-month change are null too.
  • History is the latest published values. When a past month is revised, the stored value is replaced.

Getting Started

There are only 3 steps for making a successful API call:
  1. Add your API key to the header of the request as X-API-KEY.
  2. Add the series parameter, which is required. Optionally add start_date and end_date (inclusive, YYYY-MM-DD; any day inside a month selects that month). With no dates you get the trailing five years.
  3. Execute the API request.
Rows come newest first in pages of up to 10. When more rows remain, the response includes a next_page_url; request it as-is to get the next page. See the pagination guide.

Example

Inflation

Example Response

Authorizations

X-API-KEY
string
header
required

API key for authentication.

Query Parameters

series
string
required

The series id, e.g. cpi_all_sa. Six concepts (all items, core, food, energy, shelter, services less energy), each seasonally adjusted (_sa) and not (_nsa). Use the /macro/inflation/series endpoint to get the list.

start_date
string

The first month to return, inclusive, in YYYY-MM-DD format; any day inside a month selects that month. Defaults to five years before end_date when both dates are omitted; omit it with an end_date to get all available history through that month.

end_date
string

The last month to return, inclusive, in YYYY-MM-DD format. Defaults to today.

cursor
string

Opaque pagination cursor from a previous response's next_page_url. When provided, all other query parameters are ignored: the cursor carries the original request's filters. Treat it as opaque; do not construct or modify it.

Response

Inflation response

inflation
object[]
next_page_url
string

Absolute URL of the next page of results. Present only when more results remain; request it as-is to continue. Each page holds up to 10 records.