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Keyterms

Improve speech recognition with custom vocabulary for your domain.

What are keyterms?

Keyterms are domain-specific words and phrases that bias the speech recognition model toward correct transcription. When you add keyterms, CrabCallr's Deepgram Nova-3 ASR engine is more likely to recognize those words accurately, even if they're unusual or technical.

When to use them

Keyterms are helpful when your conversations include words the speech engine might not recognize correctly by default:

  • Brand names — OpenClaw, CrabCallr, Supabase, LiveKit
  • Technical terms — WebRTC, ngrok, DTMF, homelab
  • Acronyms & abbreviations — STT, TTS, ASR, SIP
  • People & places — unusual names that might be misheard
  • Product-specific jargon — terms unique to your workflow

How to add keyterms

  1. Open the Settings page in your dashboard
  2. Scroll to the Keyterms section
  3. Type a term and click Add (or press Enter)
  4. Repeat for each term you want to add

To remove a term, click the × button next to it.

Limits

Limit Value
Maximum terms 100
Maximum characters per term 50

Best practices

  • Be specific — add the exact form of the word you expect to say (e.g. "Kubernetes" not "k8s" unless you say "k-eight-s")
  • Focus on 20–50 terms — a smaller, targeted list works better than filling all 100 slots. Prioritize the terms you care about most.
  • Capitalize proper nouns — write "Deepgram" not "deepgram", "iPhone" not "iphone". The model uses your casing as a hint for output formatting.
  • Use lowercase for common nouns — write "algorithm" or "protocol", not "Algorithm" or "Protocol".
  • Multi-word phrases work — "home assistant", "account number", or "customer service" can be added as a single term
  • Applies to both call types — keyterms are used for both browser and phone calls
  • Takes effect on next call — changes apply from your next call onward (no need to restart anything)

What to avoid

  • Generic common words — don't add everyday words that are rarely misrecognized ("the", "and", "computer"). They waste your token budget without helping.
  • Overly broad terms — words that appear in many contexts without specific meaning won't improve accuracy for your domain.
  • Inconsistent formatting — if you add both "API" and "api", pick one. Inconsistent casing can confuse the output.

Important: keyterms are hints, not guarantees

Keyterms bias the speech recognition model — they make it more likely to recognize your terms, but they don't guarantee it. Deepgram reports that keyterms can improve keyword recall rate by up to 90%. Actual results depend on audio quality, background noise, accent, and conversational context. The model always balances your keyterms against what it hears in the audio.

How it works under the hood

Keyterms are passed to Deepgram's Nova-3 model as biasing hints at the start of each call. The model uses them to adjust its recognition probabilities, making it more likely to transcribe your custom vocabulary correctly. All keyterms share a 500-token budget per request — CrabCallr's limit of 100 terms at 50 characters each stays well within this.