Twilio ConversationRelay
ConversationRelay is a Twilio Programmable Voice feature that runs speech recognition and text-to-speech on a phone call and streams the conversation to the developer’s own WebSocket server, where the customer’s chosen LLM or agent writes the replies. It is a building block for developers who want to run voice agents on Twilio phone numbers, not a ready-made agent. Twilio charges $0.07 per minute for it, with voice minutes and phone numbers billed separately.
Twilio ConversationRelay pricing
Twilio ConversationRelay's entry rate is $0.07 a minute; the AI model and phone minutes are billed separately. Its pricing page doesn't say whether speech recognition and the voice are included.
| Plan | Price | Includes |
|---|---|---|
| Pay as you go | $0/mo | ConversationRelay $0.07/min; Programmable Voice minutes and phone numbers billed separately |
- Contract: Pay as you go with no platform commitment; volume and custom pricing through sales
- Twilio’s conversational AI pricing page lists Conversation Relay at $0.07 per minute and says voice costs are billed separately. It does not say whether that rate covers speech recognition or text-to-speech, although Twilio’s docs say ConversationRelay handles both (Deepgram or Google speech-to-text; ElevenLabs, Google or Amazon Polly voices). No LLM is included: the customer’s own server receives the transcribed text over a WebSocket and returns replies from the model or agent of its choice. US Programmable Voice rates (Twilio’s page, current as of August 2026): local numbers $1.15/month, toll-free $2.15/month, inbound $0.0085/min local and $0.022/min toll-free, outbound $0.014/min, SIP interface $0.004/min. Conversation Intelligence, Memory and Enterprise Knowledge are optional and metered separately. Twilio says discounts are available at volume through sales.
What it does
- Answers inbound calls
- Yes
- Places outbound calls
- Yes
- Books appointments
- Unconfirmed
- Warm transfer to a person
- Unconfirmed
- Text follow-up
- Unconfirmed
- Call recording
- Unconfirmed
- Transcripts
- Yes
- CRM sync
- Unconfirmed
- Keep your number (porting)
- Unconfirmed
- Spanish
- Unconfirmed
- Other languages
- Yes
- Web chat
- Unconfirmed
- API
- Yes
- Custom voice
- Unconfirmed
Twilio’s product page says ConversationRelay supports multilingual voice AI with automatic language detection during a live call. The TwiML reference does not list languages (the default is en-US); Spanish is named only for backchannel detection.
Security and compliance
- Signs a HIPAA BAA
- Yes
- SOC 2
- Type II
- Discloses it's an AI
- Unconfirmed
Twilio’s May 2025 GA announcement says Conversation Relay is HIPAA eligible. Twilio’s HIPAA page says customers who want to sign Twilio’s Business Associate Addendum must have Security Edition or Enterprise Edition, and the HIPAA accounts docs say the BAA is signed with a Twilio account manager.
“Unconfirmed” means Twilio ConversationRelay's public pages don't say either way. Rules for AI phone calls
Company
- Headquarters
- San Francisco, CA
- Founded
- 2008
- Built for
- Small business, Enterprise
- Built on
- Third-party speech models run through Twilio: Deepgram (default) or Google for speech-to-text, and ElevenLabs (default), Google or Amazon Polly for text-to-speech. The LLM or agent is the customer’s own.
Sources
- Twilio conversational AI pricing pricing. Accessed October 22, 2026
- Twilio Conversation Relay features, compliance. Accessed October 22, 2026
- Twilio docs: Conversation Relay features. Accessed October 22, 2026
- Twilio docs: TwiML <ConversationRelay> features. Accessed October 22, 2026
- Twilio docs: initiate outbound conversations features. Accessed October 22, 2026
- Twilio blog: Conversation Relay GA (May 14, 2025) compliance, status. Accessed October 22, 2026
- Twilio and HIPAA compliance. Accessed October 22, 2026
- Twilio docs: HIPAA accounts compliance. Accessed October 22, 2026
- Twilio security overview compliance. Accessed October 22, 2026
- Twilio Programmable Voice pricing (US) pricing. Accessed October 22, 2026
- Twilio investor FAQs company. Accessed October 22, 2026
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Twilio ConversationRelay alternatives
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