# Synthflow — Enterprise voice AI platform with in-house telephony for inbound and outbound call automation.

> Source: The Agents Index — https://theagentsindex.com/synthflow-ai (structured, researched, re-verified)
> Facts last verified: 2026-09-03

Synthflow is a voice AI platform for building, testing and running phone agents that handle inbound and outbound calls. It ships its own telephony network, a visual flow designer, a simulation test centre and CRM, SIP and PBX integrations.

| Fact | Value |
| --- | --- |
| Website | https://synthflow.ai |
| Price | from $30,000/year billed annually |
| Free tier | Yes |

Building an agent from templates or from scratch, including call flows, voicemail detection and integrations, costs nothing; launching moves you onto pay-as-you-go billing for the calls and chats conducted. No published PAYG rate.

## What it does

**Done-for-you service** · Partly — You run the software, but Enterprise agreements include Synthflow-led implementation, launch and ongoing optimisation.

> Implementation, onboarding, testing, training, launch support, and ongoing optimization
> — https://synthflow.ai/pricing · Enterprise plan card, included-features list, final bullet

## How much it does unattended

**Runs autonomously** · Yes — Agents answer and place calls unattended, escalating to a human only on triggers you configure.

> They can ask clarifying questions, offer alternate responses, or escalate to a human. You can control handoff triggers based on failed attempts or sentiment.
> — https://synthflow.ai/ · FAQ, answer to "What happens if the AI gets stuck?"

**Multi-agent** · Yes — Subflows act as specialised agents that a parent flow triggers for individual tasks.

> Architect modular voice flows with a flexible, API-connected builder. Subflows act as specialized agents that handle tasks independently
> — https://synthflow.ai/ · "The Complete Voice AI OS" section, Multi-Agent System card

**Agent permissions** · Yes — Flow logic, approved knowledge sources, end-call reasons and handoff triggers bound what an agent may say or do.

> Synthflow agents follow defined logic and approved knowledge sources — ensuring compliant, brand-safe replies and zero off-script or hallucinated responses.
> — https://synthflow.ai/ · "Why Leading Teams Choose Synthflow" section, Enterprise Reliability card

## Which models it runs on

**Claude** · No — The agent model selector enumerates OpenAI GPT variants and Synthflow's own LLMs; no Anthropic model is offered.

> The AI Model selector controls which large language model powers your agent's responses. Available options include: GPT-4o ... Synthflow LLM ... Advanced Synthflow LLM
> — https://docs.synthflow.ai/general-configuration · AI Model section, full list of available options

**GPT** · Yes — The model selector lists GPT-4o, GPT-4.1 and multiple GPT-5 variants for agent responses.

> GPT-4o -- fast, versatile model balancing quality and speed.
> — https://docs.synthflow.ai/general-configuration · AI Model section, first bullet of the available options list

**Open models** · No — The published model list contains only OpenAI GPT variants and Synthflow's proprietary LLMs; no open-weight model appears.

> Synthflow LLM -- optimized for real-time, natural phone conversations. Advanced Synthflow LLM -- strongest reasoning in the Synthflow family, for complex logic and long prompts.
> — https://docs.synthflow.ai/general-configuration · AI Model section, closing entries of the available options list

**Model choice** · Partly — You pick the model per agent, but only from Synthflow's list of GPT and Synthflow LLM options.

> Pick the model that matches your latency, cost, and quality requirements.
> — https://docs.synthflow.ai/general-configuration · AI Model section, closing sentence

## Where you use it

**In your editor** · Partly — No Synthflow editor extension; Claude, Claude Code and Cowork can drive the workspace over MCP from where a developer already works.

> Claude, Claude Code, and Cowork can all manage your Synthflow workspace from a conversation.
> — https://docs.synthflow.ai/anthropic · Anthropic integration page, first paragraph under the cover image

**On the command line** · No — The deployment channels are enumerated as telephony, WhatsApp, WebSocket, chat, API, Workflows, Zapier and GoHighLevel; Synthflow ships no command-line tool.

> Deploying your Synthflow AI agent gets it live and ready to take calls or messages. Each deployment path is complementary, so you can enable several at once on the same agent
> — https://docs.synthflow.ai/deploy-your-agent · Deployment Options, opening paragraph above the channel cards (the cards enumerate every channel; none is a CLI)

**In your pipeline** · No — The connector needs an interactive browser sign-in, which the vendor says rules out unattended jobs.

> The official connector requires an interactive browser sign-in, so it is not suited to CI or scheduled jobs.
> — https://docs.synthflow.ai/anthropic · Anthropic integration page, FAQ, 'Can I use this in CI or headless runs?'

**In a browser** · Yes — Agents are created, tested and published from a hosted dashboard with an in-product assistant.

> Aurora is the workspace assistant built into the dashboard. Describe what you want in natural language to scaffold agents, query calls, manage knowledge, run simulations, and update existing agents
> — https://docs.synthflow.ai/getting-started · Introduction, second paragraph

## Whose machine it runs on

**Self-hosted** · No — Deployment choice is limited to picking one of three Synthflow-operated clusters at workspace creation.

> Synthflow operates three clusters. The table below shows where each one stores workspace data and where live processing runs.
> — https://docs.synthflow.ai/customer-region · Data Region page, paragraph introducing the cluster table

**Open source** · No — Subscriber Terms grant a non-transferable licence to use the software and forbid decompiling it.

> Synthflow grants to the User during the term of the Agreement a non-exclusive, non-transferable, non-sublicensable license to use the Software for Direct Use
> — https://docs.synthflow.ai/terms-conditions · Subscriber Terms, licence grant clause

## What it costs to run

**How it meters** · Yes — Calls are metered per second and aggregated into billed minutes; chat converts at 5 AI messages per usage minute.

> Phone calls are measured per second, starting when the human and the AI agent connect and ending when the call terminates. Partial seconds are rounded up to the nearest second.
> — https://docs.synthflow.ai/usage · How usage is measured, Calls subsection

**Free tier** · Yes — You can build an agent at no cost; charges begin at launch on a pay-as-you-go basis.

> Yes, you can start and build your AI agent for free using our library of industry templates or build your own. You can design custom call flows, set up voicemail detection
> — https://synthflow.ai/ · FAQ, answer to "Does Synthflow offer a free trial?"

**API access** · Yes — Platform API with bearer-key auth covers agents, calls, campaigns, knowledge bases and subaccounts.

> Generate a Synthflow API key under Admin > Workspace Settings > API Keys, send it with Bearer authentication, and follow basic key-management practices.
> — https://docs.synthflow.ai/authentication · Authentication page, summary line

**MCP server** · Yes — A hosted MCP server in three regions exposes agent, call and knowledge-base tools to MCP clients.

> The Synthflow MCP server lets you use Synthflow directly from the AI tools you already prefer, such as Claude, Claude Desktop, ChatGPT, and Codex.
> — https://docs.synthflow.ai/mcp-server · MCP Server page, opening paragraph

**Bring your own key** · Partly — Your own OpenAI or Azure OpenAI key can power supported models, but the option is enabled per account; telephony can also be your own carrier or SIP trunk.

> After connection, Synthflow routes supported LLM traffic through your OpenAI account using your API key. Billing and usage limits follow the terms of your OpenAI account.
> — https://docs.synthflow.ai/openai · Bring your own key section, after the connect steps

## Buying it for a team

**A company can buy it** · Yes — Sold as a sales-led annual Enterprise agreement with MSA/DPA and security review.

> MSA/DPA support, data handling review, workspace controls, and enterprise security review
> — https://synthflow.ai/pricing · Enterprise plan card, included-features list

**Seat model** · No — Pricing is scoped on call volume and concurrency, not on seats; workspace members are governed by roles instead.

> Enterprise contracts start at $30,000 annually. Final pricing is scoped around call volume, concurrency, telephony setup, integrations, security needs, and launch support.
> — https://synthflow.ai/pricing · Enterprise plan card, price description

**Pooled budget** · Yes — Subaccounts draw on the parent agency's minute balance and share its concurrency total, with optional caps.

> Subaccounts share the main agency account's minutes. You can allocate caps with Limits and defaults.
> — https://docs.synthflow.ai/getting-started · FAQ, answer to "Do subaccounts get their own minutes?"

**Admin controls** · Yes — Agency admins grant or revoke per-subaccount permissions for actions, agent types, editor options and integrations.

> If you want to enable or disable specific actions for all or certain subaccounts, you can do that in Admin. For example, you can only allow select subaccounts to buy phone numbers or deploy agents.
> — https://docs.synthflow.ai/manage-subaccount-permissions · Permissions page, opening paragraph

**Audit log** · Partly — API logs give an audit trail of every request an agent makes, with retention set by plan; no admin-action audit log is documented.

> API logs: Audit trail of all API requests triggered by your agents
> — https://docs.synthflow.ai/logs · Logs overview, list of log types

**Single sign-on** · Partly — SAML/OIDC via WorkOS with Okta, Entra ID, Google SAML and Auth0, but only on Enterprise.

> Single Sign-On (SSO) is available on Enterprise plans only. ... Synthflow uses WorkOS as the SSO infrastructure provider.
> — https://docs.synthflow.ai/security · Single sign-on section, opening paragraphs

## What happens to your code

**Opt out of training** · Yes — A blanket contractual commitment not to train on customer input or output; published Marketplace templates are the one carve-out.

> Synthflow does not use Customer Input or Output to train, fine-tune, or otherwise improve its own or any third party’s AI or machine learning models.
> — https://docs.synthflow.ai/terms-conditions · Subscriber Terms, 'Intellectual Property Rights' section, clause 14.4

**Data residency** · Yes — Choose a US or EU cluster keeping storage and compute in one region; the legacy Global cluster stores in the EU. Choice is permanent.

> US and EU keep both storage and compute in a single region. New workspaces should use US or EU unless you are continuing on the legacy Global architecture.
> — https://docs.synthflow.ai/customer-region · FAQ, answer to "What is the difference between Global, US, and EU?"

**Getting out** · Partly — Manual CSV export of call logs is available to all; scheduled exports to S3, BigQuery or SFTP are Enterprise-only, and unused minutes carry over only if the agreement says so.

> If you're an Enterprise client, you can configure daily exports of your call data to destinations of your choice, including Amazon S3, Google BigQuery or SFTP servers.
> — https://docs.synthflow.ai/export-call-data · Set up automatic daily exports section

**Certifications** · Yes — ISO 27001:2022, SOC 2, GDPR, HIPAA and PCI DSS v4.0.1, with documents in a Trust Vault.

> Synthflow is compliant with: ISO 27001:2022, SOC 2, GDPR, HIPAA, PCI DSS V4.0.1
> — https://docs.synthflow.ai/security · Certifications section, compliance list

## Provenance

Every fact above comes from the vendor. Nothing here is independently corroborated yet.

## Coverage elsewhere

Pages about this product that the vendor does not control. The label states how independent each one is.

| Source | Kind | Read |
| --- | --- | --- |
| callcentrehelper.com | Independent source | 2026-08-25 |
| supermia.ai | Independent source | 2026-08-25 |
| zeeg.me | Independent source | 2026-08-25 |
| techinberlin.com | Independent source | 2026-08-25 |

## What changed

- 2026-09-03 — Capabilities · Commercial terms · Free tier
- 2026-08-31 — Capabilities · Commercial terms · Free tier · Price
- 2026-08-23 — Summary
- 2026-08-19 — Summary

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