This function uses REDCap's API to select and return data.

  overwrite_with_blanks = TRUE,
  convert_logical_to_integer = FALSE,
  verbose = TRUE,
  config_options = NULL,
  handle_httr = NULL



The base::data.frame() or tibble::tibble() to be imported into the REDCap project. Required.


The uri/url of the REDCap server typically formatted as "". Required.


The user-specific string that serves as the password for a project. Required.


A boolean value indicating if blank/NA values in the R data frame will overwrite data on the server. This is the default behavior for REDCapR, which essentially deletes the cell's value If FALSE, blank/NA values in the data frame will be ignored. Optional.


If TRUE, all base::logical columns in ds are cast to an integer before uploading to REDCap. Boolean values are typically represented as 0/1 in REDCap radio buttons. Optional.


A boolean value indicating if messages should be printed to the R console during the operation. The verbose output might contain sensitive information (e.g. PHI), so turn this off if the output might be visible somewhere public. Optional.


A list of options passed to httr::POST(). See details at httr::httr_options(). Optional.


The value passed to the handle parameter of httr::POST(). This is useful for only unconventional authentication approaches. It should be NULL for most institutions. Optional.


Currently, a list is returned with the following elements:

  • success: A boolean value indicating if the operation was apparently successful.

  • status_code: The http status code of the operation.

  • outcome_message: A human readable string indicating the operation's outcome.

  • records_affected_count: The number of records inserted or updated.

  • affected_ids: The subject IDs of the inserted or updated records.

  • elapsed_seconds: The duration of the function.

  • raw_text: If an operation is NOT successful, the text returned by REDCap. If an operation is successful, the raw_text is returned as an empty string to save RAM.


Currently, the function doesn't modify any variable types to conform to REDCap's supported variables. See validate_for_write() for a helper function that checks for some common important conflicts.


The official documentation can be found on the 'API Help Page' and 'API Examples' pages on the REDCap wiki (i.e., and If you do not have an account for the wiki, please ask your campus REDCap administrator to send you the static material.


Will Beasley


if (FALSE) {
# Define some constants
uri            <- ""
token          <- "D70F9ACD1EDD6F151C6EA78683944E98"

# Read the dataset for the first time.
result_read1   <- REDCapR::redcap_read_oneshot(redcap_uri=uri, token=token)
ds1            <- result_read1$data

# Manipulate a field in the dataset in a VALID way
ds1$telephone  <- paste0("(405) 321-000", seq_len(nrow(ds1)))

ds1 <- ds1[1:3, ]
ds1$age        <- NULL; ds1$bmi <- NULL # Drop the calculated fields before writing.
result_write   <- REDCapR::redcap_write_oneshot(ds=ds1, redcap_uri=uri, token=token)

# Read the dataset for the second time.
result_read2   <- REDCapR::redcap_read_oneshot(redcap_uri=uri, token=token)
ds2            <- result_read2$data

# Manipulate a field in the dataset in an INVALID way.  A US exchange can't be '111'.
ds1$telephone  <- paste0("(405) 321-000", seq_len(nrow(ds1)))

# This next line will throw an error.
result_write   <- REDCapR::redcap_write_oneshot(ds=ds1, redcap_uri=uri, token=token)