Smallest AI Alternatives: Keep the Voices, Own the Platform

The main Smallest AI alternatives fall into two groups. Vapi, Retell AI, Bland AI, Synthflow and Voiceflow are hosted closed-source platforms like Smallest's Atoms. Dograh, LiveKit Agents and Pipecat are open source. Dograh, which you can self-host or run on Dograh Cloud, runs any supported model with your own keys, Smallest's Lightning voices and Pulse speech-to-text included.

Key Takeaways

• Smallest's Lightning voices and Pulse speech-to-text run inside Dograh with your own key.
• Smallest's self-hosting covers its speech models, under a license key from Smallest.
• Of the open-source options, only Dograh ships as a full platform.

This guide starts with what Smallest AI sells and why teams look past its Atoms platform. We compare the alternatives on license, hosting and models in one table, then cover what Smallest costs, when staying is the better call and what moving off takes, with Dograh as the worked example.

What Smallest AI sells, and why teams look elsewhere

Smallest AI is a model company first, and it rents a hosted voice agent platform built on those models. Its own speech models are Lightning for text to speech and Pulse for speech to text. Electron, a small language model, is sold on Enterprise only, and Hydra, a speech-to-speech model, is in beta.

The company is young and well funded. It was founded in late 2024, and in July 2026 it raised a $13 million Series A, bringing total funding past $21 million, according to TechCrunch, which names RingCentral and Truecaller among its customers.

The agent platform is called Atoms. You build an agent as a Single Prompt, in Conversational Flow, its visual workflow builder, or in Python with the Agent Crews SDK. Numbers can be rented from Smallest or brought over a SIP trunk, and Atoms adds campaigns, keypad input, call recording and an MCP server for AI coding tools.

Teams start looking at Smallest AI competitors for concrete reasons. The platform's code is closed. Smallest's public GitHub holds SDKs, examples, an MCP server and Helm charts, not the agent platform itself. Inside an agent, transcription and voice come from Smallest's own models. You can plug in your own language model only through an OpenAI-compatible endpoint reachable from the public internet, so a model on a private network will not work.

Scale and hosting are the other triggers. Pay as you go includes 20 concurrent calls with no option to add more, so a busier line means an Enterprise plan. Smallest AI runs agents on its own cloud. Its Enterprise plan lists on-premise deployment, and its self-hosting docs cover the speech models, run under a license key from Smallest. A signed BAA comes on Enterprise plans with zero data retention turned on.

How we compared the alternatives

Four questions sort the field. The license decides whether you can read the code and keep running it if the vendor changes course. Where it runs means your own servers without a sales contract, or the vendor's cloud only. Model choice covers bringing your own key (BYOK) and hosting open-weight models. Last, a full platform ships the builder, telephony, call history and QA, while a framework leaves the product to your developers.

Prices come from each vendor's own pricing page and sit in the sections below. Latency is left out, because it depends on your models and phone path far more than on the platform. Measure it on your own calls.

Search results for Smallest AI alternatives also list speech APIs such as Deepgram, ElevenLabs and Cartesia. Those replace Smallest's models, not its agent platform. It works the other way round too, since Smallest's own models can run inside a different platform, as the Dograh section below shows.

Smallest AI alternatives in one table

Of the three you can run yourself, only Dograh ships as a full platform. LiveKit Agents and Pipecat are frameworks.

Dograh: the open-source Smallest AI alternative

Dograh's code is open under BSD-2-Clause, so anyone can read and change it, or self-host it with Docker Compose. Self-hosted, it runs 10 calls at once by default. You can raise that limit, though your servers and phone carrier set the real ceiling.

Its GitHub repository holds the whole platform rather than SDKs around a closed service. That includes telephony, Campaigns for outbound lists, HTTP API tools that read and write your systems during the call, call traces and automatic QA.

If you like Smallest's voices, keep them and own the platform. Smallest AI is a built-in provider in Dograh, with Lightning v3.1 and v3.1 Pro for the voice and Pulse for speech to text, set on the Models page with your own Smallest API key. Smallest publishes its own guide to the same setup, and it calls Dograh an open-source platform for building and deploying voice agents.

Because Dograh is the orchestration layer that runs the call flow, tools and telephony, the speech and language models are a separate layer you choose. That can be Dograh's own models, any supported provider with your own keys, or open-weight models behind an OpenAI-compatible endpoint such as Ollama or vLLM, on your own network. With your own keys, the call audio still reaches each provider, Smallest included. It stays in-house only when the models run on your own servers too.

Agents are built in the visual workflow builder, as nodes joined by pathways, or from an AI assistant through Dograh's MCP server. It connects to your own carrier, such as Twilio, Vonage, Plivo, Telnyx, Cloudonix, Exotel, Vobiz or Asterisk ARI, or Dograh SIP.

When a call needs a person, Transfer Call works on Twilio, Telnyx, Plivo, Cloudonix and Asterisk ARI. Dograh calls the destination first and connects the caller only when someone answers. On Twilio, it can play a short spoken introduction to both people before connecting them. No summary goes across by default, so the agent writes the caller's details to your system first.

QA runs on editor test calls and on live calls, and scores each step of the call separately, with its own tags, a 1-10 score, sentiment and a summary. For every feature side by side, see our Dograh vs Smallest AI comparison.

What it leaves to you is just as concrete. There is no keypad (DTMF) input, no built-in SMS and no transcript redaction, and CRMs are reached through HTTP API tools and webhooks rather than native integrations. Self-hosting also puts the servers, updates and uptime on your team. Self-hosted Dograh has no per-minute platform fee (servers, model keys and phone minutes still cost). Dograh Cloud has a 1¢-a-minute platform fee.

Open Source Alternative to Vapi / Retell

Self-hosted voice agent platform — no per-minute fees

dograh-hq/dograh

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Hosted alternatives to Smallest AI

Five hosted Smallest AI competitors come up most often. Like Atoms, each runs on the vendor's cloud with closed code.

Vapi

Vapi is a developer platform where you bring your own model keys or a custom LLM, and it bills $0.05 a minute for hosting, with models and phone on top. Its Pro plan has a $999 monthly minimum, and HIPAA is a $2,000-a-month add-on. Vapi retired its visual Workflows on 18 August 2026, so a team used to Conversational Flow will build in Assistants and Squads instead. Our guide to Vapi alternatives covers Vapi's side of the field.

Retell AI

Retell AI costs $0.07 to $0.31 a minute in total, from $0.055 for its voice infrastructure. Every account gets 20 concurrent calls free, and each extra one is $8 a month, which matters if Smallest's fixed ceiling is your reason to move. It has a visual Conversation Flow builder, OpenAI's realtime speech-to-speech models and a BAA that pay-as-you-go customers sign themselves. See our guide to Retell AI alternatives.

Bland AI

Bland AI runs on its own speech and language models, and one per-minute rate covers them, $0.14 a minute on Start, or $0.12 plus $299 a month on Build, with phone time on top. Start allows 100 calls a day. Bland picks the models on its self-serve plans, much as Smallest's agents use its own speech models, and on-prem or VPC deployment comes on Enterprise.

Synthflow and Voiceflow

Synthflow now sells only Enterprise contracts, from $30,000 a year, with its Flow Designer and launch support inside. Voiceflow builds one support agent across chat and phone, with phone usage at $0.05 a minute on self-serve plans plus model credits, and private cloud on Enterprise. Our guides to Synthflow alternatives and Voiceflow alternatives cover each one.

Open-source routes: LiveKit Agents and Pipecat

Smallest's on-premise option is licensed software from Smallest, while open source lets you read, change and run the code with no license key. Neither one alone keeps call audio in-house. That also needs self-hosted models.

LiveKit Agents (Apache-2.0) and Pipecat (BSD-2-Clause) are the two open-source frameworks teams weigh most. Pipecat is a Python framework from Daily, and Dograh itself is built on a fork of it. In our experience it is an excellent base, but production adds phone integrations, call history, QA on live calls and the call lifecycle, which is the part Dograh ships. LiveKit Agents runs on the LiveKit media server, and both have managed clouds.

Our comparison of the best open-source voice AI platforms goes deeper on the frameworks. If open source is your main reason for leaving, our post on the open-source alternative to Smallest AI explains what changes when you own the platform and the models.

What Smallest AI costs

Smallest AI prices an agent minute in layers, so the total depends on the models you pick. Smallest's pricing page lists Pay as you go at $0.09 to $0.21 a minute, with $10 in free credits and no contract, and Enterprise from $0.05 a minute.

The layers are a hosting fee of $0.01 a minute, then speech to text, the language model at cost and text to speech, or one speech-to-speech model in place of the last three. Phone numbers are $10 a month each, and add-ons such as PII removal and the knowledge base are billed on top. Our breakdown of Smallest AI pricing works through each layer and a sample minute.

When staying on Smallest AI makes sense

Smallest AI is the better fit for some teams, and the reasons are concrete. If you want one vendor for the models and the agent platform, on one bill, Atoms gives you that, with 20 concurrent calls from the first day. Its transfers can brief the person privately with a whisper message before the caller joins, agents can take keypad input, and a PII removal add-on strips sensitive details. Salesforce integration is available today.

Buyers who need reports on the vendor itself get SOC 2 Type II and ISO 27001, and Smallest signs a BAA on Enterprise plans with zero data retention turned on. A self-hosted Dograh install answers that need another way. It sits inside your own compliance perimeter, so no BAA with Dograh is needed. Your model providers may need their own, and the phone carrier may too, depending on what it stores.

What moving off Smallest AI takes

Moving is lower-risk than it sounds, because it can happen one number at a time, with Atoms answering the rest until each rebuilt agent passes its tests. Lock-in is a real cost, though. In a Zapier survey of US enterprise executives published in April 2026, only 6% could drop their main AI vendor with no disruption.

There is no Smallest importer in Dograh, so treat each Atoms agent's prompt and flow as the spec. A Single Prompt agent becomes one prompt in a node, and a Conversational Flow agent becomes nodes and pathways. Rebuild it by hand in the builder, or have an AI assistant build it through Dograh's MCP server.

The voice can come with you. Set Smallest AI as the voice provider with your own key and pick the same Lightning voice, if it appears in Dograh's Smallest voice list. For numbers on your own SIP trunk, point the trunk at Dograh one number at a time. For numbers rented from Smallest, ask Smallest about porting them. Test each rebuilt agent on a real phone line before any number moves, because browser test calls cannot transfer.

Picking your Smallest AI alternative

Teams that would rather write the agent in code can start with LiveKit Agents or Pipecat. On a hosted plan, Vapi suits developers who want an API and their own keys, and Retell AI suits teams that need more than 20 calls at once without a contract. Bland AI fits teams happy for the vendor to pick every model, Synthflow a vendor-built launch under one contract, and Voiceflow one agent across chat and phone. Stay on Smallest AI if its own models on one bill are the point.

If you want the platform's code and your own choice of models, Dograh answers the reasons that start most of these searches. It is open source and runs on your own servers or on Dograh Cloud, and Smallest's voices can come with you. To try it, run it from GitHub with Docker Compose, or start on the hosted Cloud.

Whichever you shortlist, run the same call script on a real phone line, because most phone calls still reach the agent as 8 kHz audio, while a browser demo runs at 16 kHz.

Each part of this guide has its own deep dive:

• Dograh vs Smallest AI
• Open-Source Alternative to Smallest AI
• Smallest AI Pricing Explained