Atoms is Smallest.ai’s platform for building voice agents that answer and place phone calls, using a no-code builder or APIs and SDKs. Agents run on numbers rented through the platform or on the customer’s own SIP trunk, and Smallest.ai markets them for support, sales, bookings and outbound campaigns. Pay-as-you-go billing charges a $0.01 per minute hosting fee plus separately priced speech-to-text, language model, voice and telephony, and an Enterprise plan is quoted.
Smallest.ai Atoms pricing
Smallest.ai Atoms's entry rate is $0.01 a minute, a platform fee: speech recognition, the AI model, the voice and phone minutes are billed separately.
| Plan | Price | Includes |
|---|---|---|
| Pay as you go | $0/mo | Hosting $0.01/min; speech-to-text ~$0.009/min; LLM at cost; text-to-speech ~$0.09/min; numbers $10/month each; 20 concurrent calls with no extra concurrency; unlimited agents; $10 free credits |
| Enterprise | Quote | $0.09-$0.21/min depending on models; custom concurrency; HIPAA zero data retention, SOC 2 and SSO included; 99.99% uptime SLA; dedicated infrastructure |
- Contract: Pay as you go has no commitments or long-term contracts; Enterprise pricing is tailored
- Smallest.ai’s agent pricing page lists a flat hosting fee of $0.01 per minute (‘Smallest Hosting Fees’) on Pay as you go and prices each other layer separately: speech-to-text about $0.009/min, LLMs at cost (ChatGPT 4.0 about $0.0448/min, ChatGPT 4.1 $0.045/min, ChatGPT 5.2 $0.056/min), text-to-speech about $0.09/min, or a speech-to-speech model at cost (ChatGPT Realtime about $0.10/min, ChatGPT Realtime Mini about $0.02/min) in place of the separate layers. Renting a phone number costs $10 per number per month; bring-your-own telephony is ‘At Cost’. The page’s price-per-call line reads ‘As low as $0.05/minute’ and, for Enterprise, ‘$0.09 - $0.21/minute’ depending on the models; it does not show how the $0.05 figure is built. Pay-as-you-go add-ons: HIPAA zero data retention $1,000/month, PII removal $0.01/min, knowledge base $3/GB/user and $2 per 1,000 queries. Concurrency is capped at 20 calls on Pay as you go.
What it does
- Answers inbound calls
- Yes
- Places outbound calls
- Yes
- Books appointments
- Yes
- Warm transfer to a person
- Yes
- Text follow-up
- Unconfirmed
- Call recording
- Yes
- Transcripts
- Yes
- CRM sync
- Yes
- Keep your number (porting)
- Unconfirmed
- Spanish
- Yes
- Other languages
- Yes
- Web chat
- Unconfirmed
- API
- Yes
- Custom voice
- Yes
The voice agents page says voices are available in 31 languages (it also cites 15+ text-to-speech and 38 speech-to-text languages). The Atoms FAQ names English, Spanish, French, German, Portuguese and Hindi and says available languages depend on the selected voice.
Integrations
As listed by Smallest.ai Atoms. Integrations not listed may still be possible through an API or Zapier.
Security and compliance
- Signs a HIPAA BAA
- Yes
- SOC 2
- Type II
- Discloses it's an AI
- Unconfirmed
- Consent capture tools
- Unconfirmed
- Do-not-call scrubbing
- Unconfirmed
- Calling-hour controls
- Unconfirmed
The Atoms FAQ answers ‘Do you sign HIPAA BAAs?’ with yes, on Enterprise plans with Zero Data Retention enabled, and points to sales@smallest.ai. The agents pricing page separately lists HIPAA zero data retention as a $1,000/month add-on on Pay as you go and does not say whether a BAA comes with that add-on.
“Unconfirmed” means Smallest.ai Atoms's public pages don't say either way. Rules for AI phone calls
Company
- Built for
- Small business, Enterprise
- Industries
- Medical, Real estate, Hospitality, Automotive, Financial services, Ecommerce
- Built on
- Smallest.ai’s own Pulse speech-to-text (named on the pricing page), with LLMs billed at cost (the pricing page lists ChatGPT 4.0, 4.1 and 5.2) or OpenAI Realtime speech-to-speech models.
Sources
- Smallest.ai voice agent pricing pricing, compliance. Accessed October 22, 2026
- Smallest.ai voice agents features, compliance, company. Accessed October 22, 2026
- Atoms docs: FAQ compliance, features, integrations, pricing. Accessed October 22, 2026
- Atoms docs: calling features. Accessed October 22, 2026
- Atoms docs: built-in actions features. Accessed October 22, 2026
- Atoms docs: phone numbers features, integrations. Accessed October 22, 2026
- Smallest.ai: Series A announcement (Oct 5, 2026) company. Accessed October 22, 2026
- Smallest.ai terms of service company. Accessed October 22, 2026
Spot something out of date? Email contact@aivoiceagentvendors.com with a link to the vendor's page. Fixes are listed on Corrections.
Writing about Smallest.ai Atoms? Embed this listing or download the data.