> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rhizomeai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# FDA Untitled Letters

> Search filters and result fields of fda_untitled_letters.

* **Dataset id:** `fda_untitled_letters`
* **Jurisdiction:** US · FDA
* **Date field:** `letter_date`. The search's top-level `date_from` and `date_to` filter on it.
* **Access:** any API key.

## Filters

Send these under `filters.fda_untitled_letters` in a [search](/api-reference/v3/search) request. A filter not listed here, or a value of the wrong type, is a 400. The top-level `date_from` and `date_to` set `date_from` and `date_to` below, so give a date in one place only.

<ParamField body="company" type="string">
  Keyword match on company name (BM25 tokenized). Example: 'Sanofi'.
</ParamField>

<ParamField body="product" type="string">
  Keyword match on the drug/product named in the letter (BM25 tokenized). Example: 'FILSPARI' or 'sparsentan'.
</ParamField>

<ParamField body="has_closeout" type="boolean">
  true returns only letters that have a close-out (resolution) letter posted; false returns only letters without one. Omit to include both.
</ParamField>

<ParamField body="date_from" type="string (date)">
  Inclusive lower bound on the letter issue date (YYYY-MM-DD).
</ParamField>

<ParamField body="date_to" type="string (date)">
  Inclusive upper bound on the letter issue date (YYYY-MM-DD).
</ParamField>

## Fields

Each result from this dataset has these in `fields`:

`closeout_url`, `company`, `letter_date`, `product`, `url`


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.