Fetching Data from FRED

Every function in this vignette queries the FRED web API, so none of the code below is executed when the vignette is built. The results shown were produced by running the same code in an interactive session; copy any chunk into R with your own API key to reproduce it.

The eFRED package makes it easy to import any number of series from the FRED website into a single data.frame.

First, you will need an API key. You can freely obtain one by following the instructions at https://fred.stlouisfed.org/docs/api/api_key.html. The API key is a 32 character, lower-cased string. Once you have registered for one, assign it to a variable or use the set_fred_key function.

library(eFRED)
api_key <- "abcdefghijklmnopqrstuvwxyz123456"
set_fred_key(api_key)

The package does not ship a key of its own, so this step is required. Functions that need a key and cannot find one stop with a message explaining how to get and register one. If you would rather not register the key in every session, set FRED_KEY in your .Renviron file instead.

Almost all of the eFRED functions require an API key. The set_fred_key function sets the default key that is used by the functions so that you do not need to directly pass the key each time the function is called.

FRED data can be extracted by using the fred function. The general format of the function is fred(name1 = "code1", name2 = "code2", ...), where "code" is the unique series ID that can be found next to each series’ title at https://fred.stlouisfed.org/, and name is the new label for the series in the resulting data.frame. If no name is provided, then the code will be used. Any number of series can be used and each code can be a character vector containing with multiple entries.

The following searches for two series: “GDPC1” (Real GDP) and “UNRATE” (unemployment rate).

df <- fred(y = "GDPC1", "unrate", all=FALSE)
head(df)

The column containing the data for GDP is named "y". Since no name was provided for "UNRATE", the column name is the same as the series. Note that the codes are not case sensitive. The fred function automatically converts all codes to uppercase. The last argument, all=FALSE, is included because GDP and the unemployment rate have different frequencies (quarterly vs annual) and different starting periods. When all=FALSE is used, the data.frame forces each value to the shortest series; otherwise, the frequency would be monthly with many NA values for y.

If a series id does not exist, that series is skipped with a warning and the remaining series are still returned. If the FRED API itself cannot be reached, or returns something that cannot be parsed, eFRED prints an informative message and returns no data for that request rather than raising an error. Either way, if no series at all could be retrieved, fred returns NULL.

The raw information about each series is contained within the data.frame’s info attribute, unless info=FALSE is included. The attribute holds 16 columns; a few are shown below.

info <- attr(df, "info")
info[, c("id", "title", "units_short", "frequency")]

The eFRED package contains a variety of other functions to interact with the FRED API. For example, the fred_search function can be used to search for various series. The example below searches for series based on the query "unemployment". The args parameter is a list containing other search parameters. In this case, search is limited to only the top three results.

search_results <- fred_search("unemployment", args = list(limit = 3))
search_results[, c("id", "frequency", "units_short")]

To grab each of these series, we can use the command fred(search_results$id, info=FALSE). The information about each is not needed since we have it from the search results.

The eFRED package also contains functions to search across tags, categories, releases, and much more.

Fetching Data from FRED

Christopher Mann

2026-10-22