Synthflow

Synthflow (formerly Fine Tuner) is an enterprise voice AI platform for building, testing and running phone agents on its own telephony, for contact centres and high-volume call teams.

What is Synthflow?

Synthflow is an enterprise voice AI platform for automating phone calls. Businesses use it to build AI voice agents that answer inbound calls, make outbound calls, book appointments, handle support requests and route conversations to people when needed. The product was previously known as Fine Tuner, and the old fine-tuner.ai domain now carries Synthflow branding.

Synthflow targets large organisations such as contact centres, BPOs, healthcare providers, retailers and financial services firms that handle high call volumes. A key differentiator is that it runs its own telephony infrastructure while still connecting to existing SIP or PBX setups.

Common deployments include AI receptionists, answering services, appointment setters, IVR replacement and concierge-style lines. The agents are multilingual and can pull data from business systems during a call, for example to check an order, confirm a booking or open a support ticket before handing over to a human agent.

Key Features of Synthflow

Visual Flow Designer and multi-agent setup

Teams design call logic visually, connect APIs and split complex calls into subflows that act as specialised agents, giving fine control over what the AI does at each step.

In-house telephony

Synthflow operates its own communications network and deploys infrastructure in the regions customers need. It also supports bringing your own carrier or SIP trunk and connects with systems such as Cisco, Avaya, Genesys and RingCentral.

Test Center and sandbox

Before launch, agents are checked with simulated calls against accuracy and compliance goals. Versioning lets teams compare, roll back and update agents without downtime.

Monitoring and Auto-QA

Live dashboards show every call, webhook and API request, and automated quality checks review conversations so insights can feed into the next version of an agent.

Omnichannel conversations

Beyond voice, the same agents can be deployed to chat, SMS and other channels, with integrations for CRMs, calendars, HubSpot, Salesforce, Zapier and more.

BELL deployment framework

Synthflow structures projects around Build, Evaluate, Launch and Learn stages, a repeatable method meant to reduce the risk of putting AI on live phone lines.

Synthflow Pricing

Synthflow now sells enterprise contracts only, with no self-serve plan listed on its pricing page. Final pricing is scoped through the sales team.

Prices checked on October 27, 2026; check the official pricing page for current plans.

Who Should Use Synthflow?

• Contact centres and BPOs that want to automate tier-1 and overflow calls.
• Healthcare, insurance and service businesses that book many appointments by phone.
• Retailers automating order tracking and support calls.
• Enterprises that need control over telephony, compliance and data handling.

Is Synthflow Worth It?

For enterprises with heavy phone traffic, Synthflow offers a complete package: agent design, testing, its own telephony, monitoring and hands-on launch support. Owning the telephony layer is a genuine advantage for latency and reliability, and the testing and versioning tools address the real risk of deploying AI on customer calls.

However, it is not for small businesses or individual developers. The entry point is a $30,000 annual contract, there is no self-serve trial listed, and pricing requires a sales conversation. Teams wanting to experiment cheaply will need to look at developer-oriented voice agent platforms instead. If you run a large call operation and want a managed rollout, Synthflow is worth a demo. Details are on the official Synthflow pricing page.