VaxVoIP SIP Voice Agent AI SDK alternatives

VaxVoIP is a paid Windows SDK that connects SIP and IP-PBX systems to OpenAI real-time speech so developers can build multilingual voice agents, licensed by concurrent calls. When choosing an alternative, weigh whether you need a hosted platform or self-hosting, which platforms and languages you need, and whether you want no-code tools or direct code access. Fonoster is the only direct match here, and the other options cover different parts of the stack.

Comparing with

VaxVoIP SIP Voice Agent AI SDK

AI voice agent SDK, SIP SDK, VoIP SDK, OpenAI Realtime, conv

PaidWindowsAPI

View VaxVoIP SIP Voice Agent AI SDK

Quick picks

Closest match
FluentsFluents.ai is a unified AI voice agent platform that automates inbound and outbound calls,
Free plan
FonosterEmpower Customer Engagement with VoIP and SMS Solutions
Open source
008Effortless call management and analytics with AI-powered transcriptions and CRM integration

All 15 alternatives

Ranked by how well each one does what VaxVoIP SIP Voice Agent AI SDK does.

All 15Same job 1

1
Fluents
Fluents.ai is a unified AI voice agent platform that automates inbound and outbound calls,
Pick it if you run high phone volume in a contact center and need outbound dialing, CRM sync and warm call transfers with context, managed through a web platform.
- API
- Web
Covers most of itFreemiumSimilar price to VaxVoIP SIP Voice Agent AI SDKView Fluents
2
Call Support AI
AI Phone Calls just like Humans - Automate all your phone calls with AI
Pick it if you are a clinic, dealership, restaurant or ecommerce business that wants industry-specific phone agents set up in a web console.
- Web
Covers most of itPaidView Call Support AI
3
Fonoster
Same job
Empower Customer Engagement with VoIP and SMS Solutions
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Pick it if you want an open-source, self-hostable stack with SIP trunking, YAML configuration and command-line deployment, plus a free tier to start.
- Free plan
- API
- Open source
- Web
- CLI
Covers most of itFreeCosts less than VaxVoIP SIP Voice Agent AI SDK
View Fonoster
4
Dasha
Design, test and launch human-level voice conversations
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Pick it if you need on-premise deployment, mid-call language switching across 30+ languages, or failover between LLM providers.
- Free plan
- API
- Web
Covers most of itFreeCosts less than VaxVoIP SIP Voice Agent AI SDK
View Dasha
5
Synthflow AI
Create sophisticated AI agents without coding
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Pick it if you want a no-code visual designer for call flows, with simulated testing, version rollback and a built-in SIP network.
- Free plan
- API
- Web
Covers most of itFree
View Synthflow AI
6
Synthflow AI
Create Custom AI Agents Without Coding
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Pick it if you run an enterprise or BPO operation that needs multi-agent workflows and fine-tuning on past call data under contact-sales pricing.
- Free plan
- API
- Web
Covers most of itFree
View Synthflow AI
7
Poly AI
Enhance Customer Experience with Data-Driven Voice Assistants
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Pick it if you need Windows, macOS or Linux support with a free tier, PII redaction, regional data residency and voice or SMS verification.
- Free plan
- API
- Web
- macOS
- Windows
- Linux
- CLI
Covers most of itFreeCosts less than VaxVoIP SIP Voice Agent AI SDK
View Poly AI
8
Bland AI
Automate Phone Calls with AI
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Pick it if you work in healthcare, insurance or financial services and need self-hosted or on-premises deployment with support for 40+ languages.
- Free plan
- API
- Web
Covers most of itFree
View Bland AI
9
LumenVox
Enhance Customer Engagement with AI-driven Voice Technology
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Pick it if you need caller voice authentication with anti-spoofing, or MRCP and gRPC APIs to integrate with an existing contact-center IVR.
- Free plan
- API
- Web
Covers most of itFree
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10
CallMate: Candidate Connect
Automate Candidate Interviews Effortlessly
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Pick it if you run bulk outbound campaigns from spreadsheets and want a browser console with concurrency limits, knowledge base uploads and 18+ languages.
- Free plan
- Web
Covers most of itFree
View CallMate: Candidate Connect
11
008
Effortless call management and analytics with AI-powered transcriptions and CRM integration
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Pick it if you want a free, open-source option that connects to SIP trunks and PBXs and books appointments or creates tickets in your CRM.
- Free plan
- Open source
- Web
Covers most of itFreeCosts less than VaxVoIP SIP Voice Agent AI SDK
View 008
12
Haiva
Boost Your Sales with Haiva: Your Multilingual Voice Agent Buddy!
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Pick it if you want voice, chat and WhatsApp agents on one platform, with human approval for sensitive actions and a self-hostable runtime.
- Free plan
- API
- Web
- iOS
- Android
Covers most of itFreeCosts less than VaxVoIP SIP Voice Agent AI SDK
View Haiva
13
Video SDK
Build amazing live audio & video apps in minutes with Video SDK!
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Pick it if you are building in-app video calls or live streaming and want AI voice agents and SIP telephony in the same set of SDKs.
- Free plan
- API
- Web
- iOS
- Android
Covers most of itFreeCosts less than VaxVoIP SIP Voice Agent AI SDK
View Video SDK
14
Millis AI
Build Low-Latency Voice Agents Swiftly
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Pick it if you want an embeddable web widget or SDK for voice agents on websites and apps, with no-code or low-code setup.
- API
- Web
Covers most of itPaid
View Millis AI
15
Vapi
Build, Test, and Deploy Voicebots in Minutes
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Pick it if your engineering team wants an API-native voice agent platform with enterprise SSO, OAuth and role-based access control, under a free pricing model.
- Free plan
- API
- Web
Covers most of itFreeCosts less than VaxVoIP SIP Voice Agent AI SDK
View Vapi

VaxVoIP SIP Voice Agent AI SDK and its top 5, side by side

What we compared	VaxVoIP SIP Voice Agent AI SDKThis product	Fluents#1	Call Support AI#2	Fonoster #3	Dasha #4	Synthflow AI #5
What it does	AI voice agent SDK, SIP SDK, VoIP SDK, OpenAI Realtime, conv	Fluents.ai is a unified AI voice agent platform that automates inbound and outbound calls,	AI Phone Calls just like Humans - Automate all your phone calls with AI	Empower Customer Engagement with VoIP and SMS Solutions	Design, test and launch human-level voice conversations	Create sophisticated AI agents without coding
Fit for VaxVoIP SIP Voice Agent AI SDK users	—	Covers most	Covers most	Covers most	Covers most	Covers most
Pricing	Paid	Freemium	Paid	Free	Free	Free
Free plan	No	No	No	Yes	Yes	Yes
API	Yes	Yes	No	Yes	Yes	Yes
Open source	No	No	No	Yes	No	No
Platforms	Windows, API	Web, API	Web	Web, API, CLI	Web, API	Web, API

Questions about VaxVoIP SIP Voice Agent AI SDK alternatives

What are the best alternatives to VaxVoIP SIP Voice Agent AI SDK?

On AINave, the closest matches are Fluents, Call Support AI and Fonoster.

Is there a free alternative to VaxVoIP SIP Voice Agent AI SDK?

Yes. 12 alternatives have a free plan, including Fonoster, Dasha and Synthflow AI.

Which VaxVoIP SIP Voice Agent AI SDK alternatives have an API?

12 alternatives have an API, including Fluents, Fonoster and Dasha.

Is there an open-source alternative to VaxVoIP SIP Voice Agent AI SDK?

Yes. Fonoster and 008 are open source.

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