Yes: a contact center on Five9 adds AI voice agents without moving to another platform, because Synthflow's AI voice agents integrate with your existing Five9 contact center through Five9's AI Agent Connect, where Five9 documents Synthflow as an accredited third-party AI provider, and Five9 keeps your routing, queues, skills and reports. Synthflow handles 1M+ calls daily for 100+ enterprise customers.
Your callers dial the numbers they dial today and reach the IVR scripts you run today. The script sends the calls you choose to a Synthflow agent, the agent resolves what it can, and it hands every other call back to Five9 with the skill to route to and the reason why.
Synthflow on Five9
| What is said of Synthflow | Who says it |
|---|---|
| "an accredited third-party AI provider" | Five9's Synthflow Implementation Guide |
| "an enterprise AI agent platform", "now Five9-accredited for seamless integration with the Five9 Intelligent CX platform" | Five9 CX Marketplace |
| "A G2 Grid Leader for AI Agents", with an "owned telephony stack" | Five9 CX Marketplace |
| Five9 is a Tier 1 integration, "Actively tested and supported" | Synthflow docs |
| 1M+ calls daily for 100+ enterprise customers, 99.99% uptime | Synthflow facts |
| SOC 2 Type 2, ISO/IEC 27001, HIPAA, PCI DSS v4.0.1, GDPR | Synthflow security |
Five9's listing says Synthflow "lets Five9 customers add best-of-breed agentic AI to their contact center without lengthy implementation cycles", and names "more than 100 enterprise customers, including Freshworks, Batteries Plus, and Thryv". Synthflow is built for upper mid-market and enterprise contact centers, BPOs and multi-location brands, and it runs its own session border controllers and media infrastructure (Synthflow facts). Its Trust Center holds the SOC 2 Type 2 report, and Synthflow signs a HIPAA business associate agreement with customers who use its HIPAA Setting.
Enterprises add Synthflow inside the phone systems they already run. Batteries Plus runs Synthflow's AI voice agents inside Zoom Phone across more than 700 US locations, and its Chief Information Officer, Kranthi Malreddy, told Chain Store Age: "From kick-off to pilot, the roll-out with Synthflow and Zoom was just five weeks. This is one of the most impressive integrations I've seen between two pieces of software." Freshworks' own Freshcaller documentation names Synthflow among the voice AI platforms Freshcaller integrates, and across Freshworks deployments, up to 65% of routine voice requests are automated.
Book a demo with Synthflow's team for your Five9 call flow.
What stays in Five9
| Stays in Five9, as today | Added by the Synthflow agent |
|---|---|
| Your phone numbers, IVR scripts and campaigns | The conversation: the caller says why they are calling |
| Routing, queues and skills | The work: it reads and updates your systems through custom actions and answers from a knowledge base |
| Your people and their Five9 desktop | The route back: X-RouteType, X-RouteValue and X-RouteReason on the SIP BYE |
| Your Five9 reports | 15 call variables in a Synthflow group, filled on every call |
Each agent takes calls on an AI phone number from Five9; these numbers "only route calls to your agents and are not publicly dialable" (Synthflow's Five9 guide). The call arrives with eight Five9 call variables, such as the caller's number and the campaign name. When the agent is done, Five9 makes the next move: it writes the returned headers into call variables and routes the caller to a skill, a person or a number, or ends the call.
The reports Five9 gains
Five9's implementation team creates a call variable group named Synthflow and configures the call variables "to enable reporting" (Five9's guide). Each answers a question your reports ask:
| The question | Call variables in the Synthflow group |
|---|---|
| Where did the caller go next? | route_type, route_value |
| Why did the call leave the agent? | route_reason |
| How did the call end? | status, status_type, status_code, status_reason, end_call_reason, duration |
| What was said? | transcript, description, custom_meta_data |
| What data went each way? | to_iva, from_iva |
| Which agent took it? | iva_transfer_number |
Five9 can also fetch the transcript and the end-call reason from the Synthflow API after the call, so the headers stay short (Synthflow's Five9 guide).
Three places for the agent in your IVR script
Five9's implementation team assigns the agent's AI phone number to the third-party transfer module of your IVR script (Five9's guide), a module that "enables you to transfer a call to a phone number outside your VCC" (Five9). Where that module sits decides what changes:
| Where the agent sits | IVR script | Campaigns and skills | Reports |
|---|---|---|---|
| An AI branch in your menu | One branch of the Menu module goes to the agent; the others stay | Unchanged; the agent returns callers to your skills | That branch's calls gain the Synthflow variables |
| The agent first, ahead of the menu | The transfer comes before any menu; routing follows the returned route | Unchanged; skills receive callers by intent | Every call gains the Synthflow variables |
| In place of IVA Studio flows | The transfer to the AI phone number takes the place of the hand-off to the Studio IVA | Unchanged | The Synthflow variables, where the Studio data stood |
A branch is the smallest first step: one menu option, such as order status, goes to the agent, and the rest of the menu stays as it is. The agent moves to the front once that branch's calls end where they should.
From menu to intents
With the agent in front, the caller says why they are calling in place of pressing keys. The agent resolves what it can and returns each other intent to a Five9 skill: X-RouteValue names the skill and X-RouteReason says why, on the SIP BYE (Synthflow's Five9 guide). A five-option menu, worked through:
| Menu today | The caller says | The agent | Returns to Five9 | X-RouteReason |
|---|---|---|---|---|
| 1 Billing | "Why is my bill higher?" | Reads the account, explains the charge | hangup | Bill explained |
| 1 Billing | "I want to dispute a charge" | Verifies the caller | skill: Billing_Disputes | Disputed charge, verified |
| 2 Order status | "Where is my order?" | Reads the order, gives the date | hangup | Delivery date given |
| 3 Tech support | "My router keeps dropping" | Walks through the reset from the knowledge base | skill: Tech_Support, if not fixed | Router drops, reset tried |
| 4 Sales | "I want to add a line" | Asks what the caller needs | skill: Sales | Add a line |
| 0 Operator | "A person, please" | Hands over at once | skill: General | Asked for a person |
Five keys become one question, and three of the six intents can end with the agent. Each row is one Five9 Handoff action in Synthflow: its condition in plain words, X-RouteType and the skill name as Static values, and X-RouteReason as an Extractor value the agent fills from the call. Agree the route types and skill names with your Five9 team before the first test call.
One agent or several
| Setup | AI phone numbers | Fits |
|---|---|---|
| One agent with sub-agents | One | One line whose menu the agent replaces |
| Several agents | One each, from the ten Five9 provides | Separate lines or brands, each sent to its own agent |
In Synthflow's Flow Designer, the Multi-Agent System splits one agent into a main flow and sub-agents, "each a complete flow focused on one task", and all of them "share the agent's phone number, configuration, and analytics". The main flow asks the reason, each intent runs as its own sub-agent, and the caller hears one continuous conversation.
Several agents each take one of the range of 10 AI phone numbers that Five9 provides, and the transfer module of each IVR script dials the number of the agent that line needs. A BPO or an enterprise with several Five9 domains sends each domain's calls to the same agent: those domains "use the same phone number range and call routing" (Five9's guide).
Counting containment
Five9 counts what the agent does from the Synthflow call variables, in the reports your team already runs:
| Measure | What to count in Five9 |
|---|---|
| Calls the agent took | Calls sent to the AI phone number (iva_transfer_number) |
| Contained | Calls the agent returned with route_type hangup |
| Handed to people, by skill | Calls with route_type skill, grouped by route_value |
| Why calls left the agent | route_reason |
| Callers who hung up early | end_call_reason and status |
Containment is the contained calls divided by the calls the agent took. In Synthflow, custom evaluations score each call against your own success criteria, so you can check that each contained call was also resolved.
Who switches on what
| Who | What they do |
|---|---|
| Five9's account team | Adds the activation SKUs 548-0132 and 548-0133 and switches on AI Agent Connect |
| Synthflow's team | Activates AI Agent Connect on your Synthflow workspace |
| Five9's implementation team | The AI phone numbers, the Synthflow call variables, the Synthflow IVR Transfer Template v1 script and a test campaign with a test DID |
| Your team | Gives Five9 the Synthflow API URL, an API token and each agent's AI phone number; designs the intents and handoffs |
Every setup step, in order: Synthflow's Five9 integration.
Testing before callers hear it
Run the agent in Synthflow's Test Center first: each test suite generates 4 base test cases from your agent, plus one for each scenario you pick, such as Accuracy of Responses or Task Completion/Issue Resolution. Then Five9's team "tests the campaign to confirm that calls successfully reach Synthflow" (Five9's guide). A test sheet for the menu above:
- one call for each row of the intent table, each checked in Five9 for its
route_type,route_valueandroute_reason; - one call in which the caller hangs up halfway, checked for the data Five9's Query module retrieves from Synthflow;
- one call that asks for a person at the first word.
A week-by-week plan for one queue on Five9: how long it takes to deploy a voice AI agent.
FAQ
Do we have to leave Five9 to use AI voice agents?
No. Five9's AI Agent Connect "integrates your Five9 IVR system with accredited third-party AI providers" (Five9), and Synthflow is one of them. Your numbers, IVR scripts, campaigns, skills and reports stay in Five9, and the Synthflow agent takes the calls your script sends it.
Does Five9 keep our reports and routing?
Yes. The Synthflow agent returns every call with X-RouteType, X-RouteValue and X-RouteReason, and Five9 routes on them. Five9's team sets up 15 call variables in a Synthflow group for reporting, from the route and its reason to the transcript.
Can the AI voice agent hand a caller to a person in Five9?
Yes, through Five9's own routing. The agent ends its part with a Five9 Handoff action, and Five9 queues the caller for the skill, person or number that X-RouteType and X-RouteValue name. The call reaches your person with the Synthflow call variables attached, such as the reason for the call and the data the agent collected.
Can Synthflow replace our Five9 IVR menu?
Yes. With the Synthflow agent ahead of the menu, the caller says why they are calling, the agent resolves what it can, and it returns each other intent to the Five9 skill that served that menu option. A single menu branch sent to the agent is the smallest first step.
Can it take the place of our IVA Studio flows?
Yes. Where your IVR script hands calls to a Five9 Studio IVA today, Five9's implementation team points that step at the Synthflow agent's AI phone number through the third-party transfer module, and the routing after the call stays in Five9.
How long does it take?
Weeks. Five9's CX Marketplace listing gives Synthflow "enterprise implementation in weeks, not months", and Batteries Plus went from kick-off to pilot in five weeks on Zoom Phone, according to its Chief Information Officer (Chain Store Age). On Five9, Five9's team activates AI Agent Connect and builds the workflow beside Synthflow's team.
Next steps
- Every setup step on Five9: Synthflow's Five9 integration
- One billing call, header by header: intelligent virtual agents in the contact center
- One agentic call inside Five9, step by step: agentic AI in the contact center
- A phone menu replaced on any phone system: Synthflow's AI IVR
- Your Five9 call flow with Synthflow's team: book a demo
Sources read on 15 November 2026.
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