cast-API snapshot and archive queries

epidata_snapshot fetches a snapshot of signals as they appeared at a specific date (or the latest available if as_of is omitted).
epidata_archive fetches the full version history of signals across all available issues.
epidata is a wrapper that routes to one of the above based on which versioning argument is supplied.

Usage

epidata_snapshot(
  source,
  signals,
  geo_type,
  geo_values = "*",
  time_values = "*",
  ...,
  fill_method = NULL,
  as_of = NULL,
  fetch_args = fetch_args_list()
)

epidata_archive(
  source,
  signals,
  geo_type,
  geo_values = "*",
  time_values = "*",
  ...,
  fill_method = NULL,
  version = "*",
  fetch_args = fetch_args_list()
)

epidata(
  source,
  signals,
  geo_type,
  geo_values = "*",
  time_values = "*",
  ...,
  fill_method = NULL,
  as_of = NULL,
  version = NULL,
  fetch_args = fetch_args_list()
)

Arguments

source: string. The data source to query (e.g., "nssp", "nhsn"). Use epidata_meta() to discover available sources.
signals: character vector. One or more signals to query for the given source. Use epidata_meta() to discover available signals.
geo_type: string. The geography type to query (e.g., "state", "nation", "county"). Use epidata_meta() to discover available geo types for a given source and signal.
geo_values: character. The geographies to return. Defaults to all ("*") geographies within requested geographic resolution (see: https://cmu-delphi.github.io/delphi-epidata/api/covidcast_geography.html.).
time_values: timeset. Time values to return. Supports individual dates or epirange(). Defaults to all ("*"). Filtered locally after the API call.
...: not used for values, forces later arguments to bind by name
fill_method: string. Optional filter to an imputation method. The API provides alternatives of the same signal differing in how nulls were handled during geographic aggregation: "source" means no imputation or aggregation (raw source data), "fill_ave" fills nulls with the average of neighboring values, and "fill_zero" fills nulls with zero. NULL (default) returns all fill methods.
as_of: Date or NULL. The snapshot date; NULL returns the latest available version. Internally maps to the snapshot_date parameter.
fetch_args: fetch_args_list(). Additional arguments to pass to fetch(). See fetch_args_list() for details.
version: Date, string, or epirange(). A version query for the archive endpoint. Supports exact dates (e.g., "2025-10-16"), operators (e.g., "<2025-10-16"), or an epirange(). Internally maps to the version_query parameter.

Value

tibble::tibble

Usage

Arguments

Value

See also