Synthflow

Name: Synthflow
Brand: Synthflow
Price: 29 USD

No-code AI phone agents, built for agencies deploying them to small businesses

Synthflow is a no-code platform for building AI voice agents that answer and place phone calls. It provides a visual agent builder, prebuilt templates for common use cases such as receptionists and lead qualification, telephony, calendar and CRM integrations, and white-label options that let agencies resell voice agents under their own brand.

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Overview

Most AI voice platforms are built for developers, which leaves a large market unserved: the businesses that would benefit most from an agent answering the phone rarely have engineers, and the agencies serving them do not want to build orchestration for every client. Synthflow addresses that directly with a visual builder, templates, and packaging designed to be resold.

The product covers the practical path from idea to working agent without code: choose or build a flow, pick a voice, attach a knowledge base of business information, connect a calendar and a CRM, provision a number, and go live. Integrations do the heavy lifting that would otherwise require custom functions, so booking an appointment or writing a lead into a CRM is configuration rather than development.

White labeling is central to its commercial model. Agencies deploy agents under their own brand with their own pricing, which has made Synthflow common in the growing market of businesses selling AI receptionists to local companies. The trade against developer platforms is control: templates and visual configuration cover common patterns well and unusual ones poorly, and deeply custom behavior eventually hits the ceiling of a no-code tool.

Best for

Agencies building and reselling AI phone agents to small businesses, and small businesses themselves wanting a receptionist or qualification agent without engineering support.

Not the right fit for

Engineering teams building deeply customized voice experiences into a product.
Complex conversational logic that exceeds what visual configuration can express.
Contact center replacement with workforce management and omnichannel queues.
Highly regulated scripts requiring guaranteed verbatim disclosure and audit-grade control.
Markets with severe restrictions on automated calling where the use case cannot be justified.

How it works

1
You create an agent from a template or from scratch in a visual builder, defining its role, the questions it asks, and the actions it takes, with prompts written in plain language rather than code.
2
A knowledge base of business information, hours, services, pricing, policies, is attached so the agent answers questions accurately without those answers being hard-coded into a prompt.
3
Integrations connect the agent to calendars, CRM systems, and workflow tools, so booking, lead capture, and follow-up happen automatically. A phone number is provisioned or an existing one forwarded.
4
Calls are handled live with transfer to humans when needed, and afterwards transcripts, recordings, extracted data, and outcomes are available in the dashboard and pushed to connected systems.

Feature breakdown

20 features in 4 modules

No-code agent building

Getting to a working agent without engineering.

Visual flow builder: Agent behavior configured as a sequence of steps and conditions rather than written as code.
Use case templates: Prebuilt agents for receptionist, appointment booking, lead qualification, and follow-up scenarios.
Knowledge base: Business documents and information attached so the agent answers questions from source material rather than invention.
Plain language prompting: Behavior described in ordinary sentences, which is what makes the product usable by non-developers.
Multi-language agents: Agents configured per language with appropriate voices, relevant for businesses serving mixed markets.

Integrations and actions

Doing real work without custom development.

Calendar booking: Live availability checks and appointment creation in common calendar systems during the call.
CRM integration: Lead and call data written into CRM systems automatically so follow-up happens where the business works.
Workflow connections: Zapier, Make, and webhook connections for anything without a native integration.
Call transfer: Handoff to a human with context when the agent reaches its limits or the caller asks.
SMS follow-up: Text messages sent after a call to confirm details or deliver links, which raises completion rates.

Telephony and operations

Running agents on real phone lines.

Number provisioning and forwarding: New numbers or forwarding from existing business lines, including overflow when staff are busy.
Inbound and outbound calling: Answering calls and running outbound campaigns from the same platform.
Business hours handling: Different behavior in and out of hours, including full agent coverage overnight.
Voicemail detection: Recognizing answering machines on outbound calls rather than delivering a conversation to a recording.
Concurrency management: Simultaneous call handling so peak demand does not produce busy signals.

Agency features

The commercial packaging behind much of its adoption.

White labeling: The platform presented under the agency's brand and domain for client-facing use.
Sub-account management: Separate client workspaces with isolated agents, numbers, and reporting under one agency account.
Client reporting: Call volume, outcomes, and recordings presented in a form that can be shown to a client without editing.
Reusable templates: Agency-built agent templates deployed across many clients with per-client customization.
Reseller pricing structures: Plans designed to support margin when reselling agents rather than only direct use.

Use cases

4 documented

Agency selling AI receptionists to local businesses

Clients miss calls constantly, and building a custom agent per client is not commercially viable.

A templated receptionist is deployed per client under the agency's brand, customized in an hour rather than built from scratch.

Dental practice missing appointment calls

Reception is occupied with patients and a meaningful share of calls go unanswered every day.

An agent answers overflow calls, books appointments into the practice calendar, and transfers clinical questions to staff.

Home services business covering out of hours

Emergency enquiries arrive at night and go to voicemail, by which point the customer has called a competitor.

An overnight agent captures the job details, assesses urgency, and either books a visit or escalates to the on-call number.

Small sales team qualifying inbound leads

Leads call during meetings and reaching them again later takes several attempts.

The agent qualifies immediately, books time with the right representative, and writes the details into the CRM.

Pricing

from From roughly $29 per month with bundled minutes

Subscription tiers including bundled call minutes, with overage per minute beyond the allowance. Higher tiers add agent count, concurrency, white labeling, and sub-accounts.

Plan	Price	Includes
Starter	From about $29 per month	Bundled monthly minutes Visual builder, templates, and knowledge base Core integrations and one phone number
Pro	From about $199 per month	More minutes, agents, and concurrency Full integration set and advanced actions Team access and richer reporting
Agency	From about $999 per month	White labeling and sub-accounts High minute volumes and concurrency Reseller-oriented commercial terms

Billing notes

Plans bundle minutes with overage beyond them, so a busy month on a small plan costs more than the headline suggests.
White labeling and sub-accounts sit on the agency tier, which is the plan most resellers actually need.
Telephony charges vary by destination country and can be additional.
Annual billing carries a discount as published August 2026.
Pricing in this category moves frequently as underlying model costs fall; reconfirm before committing.

Value assessment: For a small business, an agent answering calls that currently go to voicemail pays for itself on a single recovered job, and the entry pricing is low enough that the calculation is easy. For agencies the value is a productized service they can sell repeatedly with margin, which is why the agency tier exists at the price it does. The ceiling is customization: businesses whose calls do not fit common patterns will find visual configuration constraining.

Strengths & limitations

Strengths

Genuinely usable without engineering, which opens the category to its most natural buyers.
Templates for common use cases shorten deployment from weeks to hours.
Native calendar and CRM integrations mean booking and lead capture work without custom functions.
White labeling and sub-accounts make it a viable basis for an agency service line.
Knowledge base grounding reduces the risk of an agent inventing answers about the business.
Affordable entry pricing suited to small business budgets.

Limitations

Visual configuration hits a ceiling on unusual or complex conversational logic.
Less control over the underlying model, voice, and latency tuning than developer platforms.
Bundled minute plans with overage make heavy usage more expensive than pure per-minute pricing.
Agency tier pricing is a significant commitment for a small reseller starting out.
Automated calling and AI disclosure rules vary by jurisdiction and continue to tighten.
Quality still depends on prompt and flow design, which templates only partly solve.

Head-to-head comparisons

5 alternatives

Synthflow vs Retell AI

from From roughly $0.07 per minute combined, with free credits to start

Retell offers more control and better tooling for teams that can write functions and manage integrations, with pure per-minute pricing. Synthflow trades control for accessibility, with templates, native integrations, and white labeling that let a non-developer deploy an agent the same day. Agencies serving small businesses at volume usually prefer Synthflow; product teams prefer Retell.

Full Synthflow vs Retell AI comparison

Synthflow vs Vapi

from From roughly $0.05 per minute platform fee, plus provider costs

Opposite ends of the market. Vapi is composable infrastructure for engineers choosing their own transcription, model, and voice providers. Synthflow is a packaged product for people who do not want to know what those words mean. The comparison is only meaningful when a buyer is deciding whether to build or to buy.

Full Synthflow vs Vapi comparison

Synthflow vs Goodcall

from From roughly $59 per month for a small call allowance

Both target small businesses wanting a phone agent without technical work, with Goodcall focusing tightly on the receptionist use case and simple setup. Synthflow is broader, covering outbound calling, more integrations, and the agency reseller model. A single business wanting the simplest possible answering agent may prefer Goodcall; agencies and businesses wanting more scope prefer Synthflow.

Full Synthflow vs Goodcall comparison

Synthflow vs Thoughtly

from From roughly $50 per month with included minutes, plus per-minute usage beyond

Both are visual no-code builders with agency packaging, and entry pricing sits in the same band (about $29 against about $50 per month with bundled minutes). The separation is measurement: Thoughtly tests conversation flows against each other and classifies call outcomes automatically, which suits teams optimizing outbound conversion. Synthflow's advantage is the breadth of templates and prebuilt integrations, which gets a client's receptionist live faster.

Full Synthflow vs Thoughtly comparison

Synthflow vs Voiceflow

from Free for individual use; paid plans from roughly $60 per editor per month

Synthflow is telephony-first: numbers, calendars, CRM writes, and agency sub-accounts, all aimed at getting a phone agent answering. Voiceflow treats voice as one channel beside web chat and messaging, and its real asset is a shared design canvas with commenting, version history, and staged environments. Agencies deploying phone receptionists choose Synthflow; support organizations designing one agent for several channels choose Voiceflow.

Full Synthflow vs Voiceflow comparison

Implementation & onboarding

Setup time: A working agent in hours using a template. A well-tuned agent handling real customer calls reliably takes one to two weeks of iteration and testing.
Learning curve: Low for the builder, moderate for conversation design. The tool is easy; writing instructions that produce sensible behavior when a caller says something unexpected still takes practice.
Onboarding: Self-serve with templates, documentation, and community resources, with onboarding assistance on agency plans.
Migration notes: Agents do not transfer between platforms and should be rebuilt rather than translated. If forwarding an existing business number, test the forwarding path and fallback behavior thoroughly before going live, since a broken forward means the business is unreachable rather than merely automated.

Platform, API & security

Platforms: Web applicationTelephony integrationAPI and webhooks
API: API and webhook access for agent management and call data, alongside native integrations with calendars, CRM systems, and automation tools.
Compliance: GDPRCCPASOC 2TCPA considerations for outbound calling
Data residency: EU and US processing options, with the company operating from Europe.
SSO: Available on higher tiers.
Security notes: Call recordings and transcripts are personal data with retention and access implications, and disclosure that the caller is speaking with an AI is required or expected in a growing number of jurisdictions.

Support & resources

Channels: Email supportIn-app chatDocumentation and community
Documentation: Practical documentation and templates aimed at non-technical builders, with agency-specific guidance on deployment at scale.
Community: Active community of agencies and consultants building voice agent service lines, with substantial shared practice on templates and pricing.

Company

Founded: 2023
Headquarters: Berlin, Germany
Ownership: Private, venture-backed
Employees: ~80 (est. 2026)
Funding: Raised venture funding including a Series A round.

Timeline

2023Founded in Berlin to make AI voice agents deployable without engineering.
2024Adds white labeling and sub-accounts, establishing the agency reseller model as a core channel.
2025Raises venture funding as small business adoption of AI receptionists accelerates.
2026Established as a leading no-code voice agent platform, particularly among agencies.

Integrations

Google Calendar
Calendly
HubSpot
Salesforce
GoHighLevel
Zapier
Make
Twilio

Frequently asked questions

10 questions

What is Synthflow?

Synthflow is a no-code platform for building AI voice agents that answer and make phone calls. It offers a visual builder, templates for receptionist and qualification use cases, a knowledge base, calendar and CRM integrations, telephony, and white-label options for agencies reselling agents to clients.

How much does Synthflow cost?

Plans start around $29 per month with bundled minutes, rising to roughly $199 for more agents and integrations and around $999 for the agency tier with white labeling and sub-accounts. Minutes beyond the bundle are charged as overage, and telephony rates vary by destination.

Do I need technical skills to use it?

No, which is the point. Agents are configured visually with plain-language instructions, and native integrations handle calendar booking and CRM writing without custom code. Some patience with conversation design is still required, but no programming.

Can an AI agent really answer my business phone?

For structured calls, yes: booking, rescheduling, answering questions from a knowledge base, taking details, and qualifying enquiries all work reliably. Unusual or emotionally charged calls do not, which is why configuring a clean transfer to a human is as important as configuring the agent itself.

Synthflow vs Retell AI: which should I pick?

Retell offers more control and better tooling for technical teams, with per-minute pricing. Synthflow is the accessible option, deployable by non-developers with templates and native integrations, plus white labeling for resale. If you have engineers, Retell gives you more room; if you do not, Synthflow gets you live.

Can agencies resell Synthflow agents?

Yes, and this is a core part of its market. The agency tier provides white labeling under your own brand and domain, sub-accounts per client, and commercial terms designed to leave margin when reselling, which has made it a common basis for AI receptionist service lines.

What happens when the agent cannot answer something?

It transfers to a human with context, provided you have configured when that should happen. Setting those triggers carefully matters more than most people expect, because an agent that keeps trying when it should hand over is the fastest route to an angry customer.

Does it work with my existing phone number?

Yes, through call forwarding, so the business keeps its published number and routes calls to the agent either always or only when staff are unavailable. Test the forwarding and its fallback behavior carefully before going live.

Do I have to tell callers it is an AI?

Increasingly yes. Disclosure requirements exist or are emerging in several jurisdictions, and expectations are rising regardless of law. Building disclosure into the greeting is both the safer legal position and, in practice, better received than callers discovering it themselves.

How does the knowledge base help?

It grounds the agent's answers in your actual business information, hours, services, prices, policies, rather than leaving the model to improvise. That materially reduces the risk of confidently wrong answers, which is the failure mode small businesses fear most about putting AI on the phone.

Editorial verdict

Synthflow understood something the developer-first platforms missed: the businesses that lose the most money to unanswered calls are exactly the ones with no engineers, and the agencies serving them need a product they can resell rather than a construction kit. Templates, native calendar and CRM integrations, a grounding knowledge base, and white labeling together make a deployable service line rather than a project. The limits are the ones every no-code product has, unusual conversational logic eventually exceeds what visual configuration expresses, and control over the underlying stack is limited. For a local business tired of voicemail, or an agency selling AI receptionists at volume, those limits rarely bind, and the value is immediate.

Written by the SaaSTracker editorial team. Awards, when shown, are judged against the published criteria in our methodology.