Keyterm Prompting

keyterm string

Pre-recorded Streaming:NovaStreaming:Flux

Instantly increase accuracy and recognition of up to 100 important terminology, product and company names, industry jargon, phrases and more.

To enable Keyterm Prompting, add a keyterm parameter in the query string and set it to your chosen key term:

keyterm=KEYTERM

To transcribe audio from a file on your computer, run the following cURL command in a terminal or your favorite API client.

curl \
  --request POST \
  --header 'Authorization: Token YOUR_DEEPGRAM_API_KEY' \
  --header 'Content-Type: audio/wav' \
  --data-binary @youraudio.wav \
  --url 'https://api.deepgram.com/v1/listen?model=nova-3&keyterm=KEYTERM'

The following examples demonstrate how keyterms can significantly improve recognition accuracy and confidence scores for industry-specific terminology. These examples show typical improvements you might see across Drive-Thru, IVR, call center, and medical transcription use cases.

When choosing keyterms, consider the following guidelines to maximize accuracy:

Good Keyterm Examples:

• Industry-specific terminology: Medical terms (tretinoin, diagnosis), technical jargon (escalation, API)
• Product and company names: Brand names, service names, competitor names
• Multi-word phrases: Common phrases in your domain (account number, customer service)
• Proper nouns: Names, brands, titles with appropriate capitalization (Deepgram, iPhone, Dr. Smith)
• Common non-proper nouns: Use lowercase (algorithm, protocol, refill)

What to Avoid:

• Generic common words: Very common words that are rarely misrecognized (the, and, is)
• Overly broad terms: Words that appear in many contexts without specific meaning
• Excessive keyterms: Stay well under the 500 token limit; focus on the most important 20-50 terms
• Inconsistent formatting: Ensure capitalization matches your desired output

Keyterms preserve formatting (including case and punctuation) which can help control how proper nouns, product names, or company names are transcribed. The model will use both the keyterm formatting and the audio context to determine the final transcription format.

Best practices for keyterm formatting:

• For proper nouns (names, brands, titles): Use appropriate capitalization (Deepgram, iPhone, Dr. Smith)
• For non-proper nouns: Use lowercase (tretinoin, algorithm, protocol)

When smart formatting is applied to the transcript, words that start sentences may be automatically capitalized regardless of keyterm formatting.

Note that while the model was trained with formatted keyterms, the final transcription may not always exactly match the keyterm’s formatting. The model balances the keyterm information with the audio context when determining capitalization and punctuation in the output.

A space must be properly URL-encoded to ensure compatibility. Both %20 and + are valid encodings, but their usage depends on context. In URL paths, spaces must be encoded as %20, while in query parameters, either %20 or + can be used.

You can pass in multiple keyterms in your query string in several ways. Do not separate keyterms with commas, semicolons, or line breaks, and do not append a weight or intensifier—keyterm does not support weights. None of these forms return an error: the API accepts the value and treats it as a single literal keyterm, so a value such as keyterm=term:0.15 silently boosts nothing rather than failing.

To boost multiple separate keyterms, repeat the keyterm parameter so each keyterm is processed individually.

curl \
  --request POST \
  --header 'Authorization: Token YOUR_DEEPGRAM_API_KEY' \
  --header 'Content-Type: audio/wav' \
  --data-binary @youraudio.wav \
  --url "https://api.deepgram.com/v1/listen?model=nova-3&keyterm=KEYTERM1&keyterm=KEYTERM2"

To boost one multi-word phrase as a single keyterm, join the words with an encoded space %20:

curl \
  --request POST \
  --header 'Authorization: Token YOUR_DEEPGRAM_API_KEY' \
  --header 'Content-Type: audio/wav' \
  --data-binary @youraudio.wav \
  --url "https://api.deepgram.com/v1/listen?model=nova-3&keyterm=term1%20term2"

In query parameters, you can also join the words of a phrase with a plus +:

curl \
  --request POST \
  --header 'Authorization: Token YOUR_DEEPGRAM_API_KEY' \
  --header 'Content-Type: audio/wav' \
  --data-binary @youraudio.wav \
  --url "https://api.deepgram.com/v1/listen?model=nova-3&keyterm=term1+term2"

Key Terms are limited to 500 tokens per request; anything beyond that will return an error like so:

Keyterm limit exceeded. The maximum number of tokens across all keyterms is 500.