An AI phone agent that never misses a call
It picks up on the first ring, every hour of the day. It answers the question, books the appointment, and passes the call to a person when it should — then makes your outbound calls too. Built on Nixflex, on your own number.
Your agent answers every call — day, night, and when the line is busy.
Every missed call is a missed customer
When a call rings out — because the team is busy, it is after hours, or too many people call at once — most callers do not leave a message. They hang up and dial the next business on the list. An AI phone agent removes that gap entirely: it answers every call the moment it comes in, so a busy line or a closed office never costs you the customer.
And it does more than pick up. Unlike an old answering machine or a rigid phone menu, it has a real conversation, works out what the caller needs, and handles it on the spot — booking, answering, or routing — rather than leaving you a voicemail to deal with later.
What to give the agent — and what to keep for a person
The calls an AI phone agent handles best are the repetitive, structured ones. The rest it routes to a human, fast and with context. A clean path back to a person is the whole point.
- After-hours and overflow, so nothing rings out
- Booking, rescheduling and cancelling appointments
- Common questions — hours, location, pricing, availability
- Routing and triage without a phone tree
- Qualifying a lead before a human follows up
- Missed-call recovery on outbound
- Genuine emergencies
- Complex or high-value conversations
- Emotionally sensitive calls
- Anything that needs a human judgement call
On a warm transfer the agent briefs the person first, with the full context of the call.
It answers your calls — and makes them
Point your number at the agent and it answers every call instantly, identifies why the caller is ringing, resolves it, and escalates the ones that need a person — with the conversation summarised and attached.
Trigger a call from the API or launch a batch campaign for reminders, follow-ups and speed-to-lead callbacks. The agent detects voicemail, leaves the right message, and remembers past calls with each person.
Live on your line in about five minutes
- Describe the agent. Write how it should greet callers, what it should answer, and what it must not do — in plain language.
- Connect your tools. Link a calendar so it can book, add custom functions to reach your systems, and set your transfer and SMS rules.
- Set the escalation path. Decide which calls go straight to a person, and to which number.
- Point your number at it. Use your own Twilio or Telnyx number. The agent starts answering and calling immediately.
Every call is transcribed, summarised and scored, and fires to your webhook — so you can read exactly what happened and tune the agent in its first week.
Why run your phone agent on Nixflex
Because we run our own engine, you can listen to a live call in real time with Live Monitor — most platforms cannot.
One rate, premium model included — not a monthly seat plus per-minute plus separate model charges.
Bring your own Twilio or Telnyx account and keep control of your numbers and costs.
The same number answers calls and replies to texts automatically — one line, two channels.
Summaries and data flow to Slack, GoHighLevel, Zapier and Make after every call.
The agent understands and switches languages automatically across ten of them.
Comparing phone-agent tools? Nixflex is a modern alternative to Retell, Vapi and Bland. See the comparison →
Frequently asked questions
What is an AI phone agent?
An AI phone agent is software that answers and makes phone calls in a natural voice. It picks up instantly, understands what the caller wants, and resolves the call — answering questions, booking an appointment, or passing the call to a person — instead of just taking a message. It works around the clock, so calls no longer ring out to voicemail after hours or when the line is busy.
Does it answer 24/7, even after hours?
Yes. The agent answers every call, day or night, and when several people call at once. Software does not sleep, so the after-hours and overflow calls that usually go to voicemail get picked up and handled.
Can it transfer to a human when a call needs one?
Yes. The agent decides when a call should go to a person — an emergency, a complex or high-value issue — and transfers it, cold or warm. On a warm transfer it briefs the person first, so the caller never has to repeat themselves.
Can it also make outbound calls?
Yes. Beyond answering, the agent places outbound calls — one through the API or a whole list as a batch campaign. Outbound calls detect voicemail and leave the right message, and they pull past call summaries so the agent remembers earlier conversations with that person.
What can it actually do on a call?
Answer questions from what you tell it, book, reschedule and cancel appointments live with your calendar, send a text during or after the call, and look things up in your own systems mid-call through custom functions. After the call it writes a summary, scores sentiment, and fires the details to your webhook and tools.
How long does it take to set up?
For a business, about five minutes in the dashboard: describe how the agent should answer, connect a calendar, set your transfer rules, and point your number at it. Developers do the same through one REST API. You bring your own Twilio or Telnyx number.
What does an AI phone agent cost?
Nixflex is a flat $0.08 per minute of voice, pay-as-you-go, with the premium model included rather than billed on top. Numbers with Live Monitor enabled bill inbound minutes at $0.09. There is no monthly platform fee to start, and because you use your own carrier, call and number costs stay on your carrier bill.
Stop letting the phone go to voicemail
Set up an AI phone agent that answers every call — live on your number in minutes.