Browse plugins


A plugin for automatically casting values in Flatfile.

npm i @flatfile/plugin-autocast
View source
@flatfile/plugin-autocast 3k installs
@flatfile/api@^1.7.4, @flatfile/hooks@^1.3.2 (+2 more)


Automatically cast values in Flatfile to their appropriate types with this plugin.

The @flatfile/plugin-autocast plugin is an opinionated transformer that will automatically convert the data in the Sheet to match the type defined by the Blueprint.

Event Type: listener.on('commit:created')

Supported field types: number, boolean, date


sheetSlug - string - (required)

The sheetSlug indicates the slug name of the sheet you want to monitor.

fieldFilters - string[]

Use the fieldFilters parameter to select specific fields to monitor. Without any specified fieldFilters, the plugin will automatically monitor all castable fields, including strings, numbers, booleans, and dates.

options.chunkSize - default: "10_000" - number

The chunkSize parameter allows you to specify the quantity of records to in each chunk.

options.parallel - default: "1" - number

The parallel parameter allows you to specify the number of chunks to process in parallel.

API Calls

  • api.sheets.get


The autocast plugin will listen for the commit:created event and cast strings, numbers, booleans, and dates to the appropriate Blueprint type. Note that the recordHook and bulkRecordHook plugins listen for the same event type. Plugins will fire in the order they are placed in the listener.


Numbers and booleans are transformed from strings to their respective types (i.e., '1' to 1, "true" to true).


String numbers (i.e '1'), string decimals (i.e '1.1'), and string numbers with commas (i.e '1,000') are interpreted as numbers.


'1', 'yes', 'true', 'on', 't', 'y', and 1 are interpreted as truthy values.

'-1', '0', 'no', 'false', 'off', 'f', 'n', 0, -1 are interpreted as falsy values.


Date strings and numbers are cast to UTC strings. For example, YYYY-MM-DD... formats are treated as ISO 8601 dates (UTC), whereas other formats are considered local time and converted to UTC:

  • '2023-08-16' => 'Wed, 16 Aug 2023 00:00:00 GMT'
  • '08-16-2023' => 'Wed, 16 Aug 2023 00:00:00 GMT'
  • '08/16/2023' => 'Wed, 16 Aug 2023 00:00:00 GMT'
  • 'Aug 16, 2023' => 'Wed, 16 Aug 2023 00:00:00 GMT'
  • 'August 16, 2023' => 'Wed, 16 Aug 2023 00:00:00 GMT'
  • '2023-08-16T00:00:00.000Z' => 'Wed, 16 Aug 2023 00:00:00 GMT'
  • 1692144000000 => 'Wed, 16 Aug 2023 00:00:00 GMT'


npm i @flatfile/plugin-autocast


import { autocast } from "@flatfile/plugin-autocast";



listener.js w/ fieldFilters

listener.use(autocast("sheetSlug", ["numberField", "dateField"]));

listener.js w/ fieldFilters & options

  autocast("sheetSlug", ["numberField", "dateField"], {
    chunkSize: 10_000,
    parallel: 2,