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

# Custom Dictionary Keyterms

> Learn how to define custom dictionary terms to be recognized

Configure `keyterms` to bias speech-to-text output. This provides ability to introduce terms unfamiliar to the speech recognition models or to improve recognition reliability for homophones and words with ambiguous pronunciation. Especially useful for proper nouns (surnames, facilities/ location), unique organizational terminology, or terms otherwise new or unknown to the speech to text system.

<Card title="Feature availability:">
  <Columns cols={3}>
    <Card icon="circle-check" horizontal href="/stt/transcribe">
      /transcribe
    </Card>

    <Card icon="circle-check" horizontal href="/stt/streams">
      /streams
    </Card>

    <Card icon="circle-check" horizontal href="/stt/transcripts">
      /transcripts
    </Card>
  </Columns>

  <br />

  <Tip>
    Looking to add a custom user dictionary to your dictation app? Use the `keyterms` configuration feature to define single words or multi-word phrases that should be recognized in speech-to-text output. See configuration details [here](/api-reference/transcribe#param#keyterms).
  </Tip>
</Card>

***

## How It Works

Currently, only the **written form** of a word needs to be specified as part of `keyterms` array to improve recognition accuracy.

Keyterm configuration is **case sensitive**, meaning defined casing is preserved with the word bias. This is different than `replacements`, which are case insensitive.

<Info>Keyterm configuration is currently limited to 1,000 item per connection</Info>
<Info>A defined `term` is limited to a length of 50 characters</Info>

The API is designed for extensibility as more functionality is planned to be added for defined `terms` (e.g., category, pronunciation).

This feature is also expected to work in conjunction with a vocabulary endpoint (under development), which will provide ability to lookup words already known to the system and bulk upload terms for recognition biasing.

<Note>
  Use of terms is **optional** for dictation configuration. Please [contact us](https://help.corti.app) to report errors, or for more information on this feature.
</Note>