Place calls from code, one or thousands
Fire a single AI call from an event in your own product, or dispatch a whole list as a batch, over one REST API. Each call is handled by your agent and returns a transcript, summary and outcome. Flat $0.08 a minute, no credits.
Two ways to place a call
Outbound splits into two shapes, and the API does both. Fire a single call the instant something happens in your systems, or hand over a list and let a batch run dial through it. Both use the same agent and return the same structured result, so you can start with one and add the other without changing how you read the outcomes.
Event-triggered, one call
Trigger a call from your own event: a new lead, a failed payment, an unconfirmed booking. One request, fired the moment it matters, straight from your product or CRM.
Batch, a whole list
Hand over a list and the calls are dialed for you, in parallel, each by the same agent. Built for reminders, follow-ups and qualification runs at volume.
Every call comes back with a result
A call you cannot read is not much use. Whether it was one call or one thousand, each returns a transcript, a summary, a sentiment score and whether it reached a person or a machine. Results land on your webhook as calls finish and are readable from GET /v1/calls, so your product knows the outcome without anyone listening back.
Handles the messy parts of outbound
Real campaigns hit voicemail, no-answers and repeat numbers. On an outbound call the agent can detect a voicemail and leave the message your prompt specifies, or hang up, so a batch does not stall on machines. Any data you attach to a call is available to the agent mid-conversation, so a reminder greets the right person and references the right detail without templating.
See the AI Phone Agent API, Webhooks and Voice Agent API pages, or the full docs. Coming from another platform? Nixflex is a modern alternative to Retell, Vapi and Bland. Compare them →
Developer FAQ
How do I place a single call from my own app?
POST to /v1/calls/outbound with the agent, the number to dial and the number to call from. It is one request, so you can fire a call the moment an event happens in your product, like a new lead, a failed payment or a booking that needs confirming.
How do I run a batch campaign?
POST a list to /v1/calls/batch and the calls are dialed for you, each handled by the same agent. It suits reminders, follow-ups and qualification runs, where you hand over a list rather than firing calls one at a time.
How do I get the result of each call?
Every call returns a result: a transcript, a summary, a sentiment score, and whether it reached a person or a voicemail. Results arrive on your webhook as calls finish, and any call is also readable from GET /v1/calls, so both a single call and a whole batch report back the same way.
Does the agent handle voicemail on its own?
Yes. On an outbound call the agent can detect a voicemail and leave the message your prompt tells it to, or hang up, so a batch run does not stall on machines. The outcome is recorded on the call either way.
Can I pass data into each call?
Yes. Any fields you attach to a call are available to the agent during the conversation, so a reminder call can greet the right person and reference the right appointment without you templating it into the prompt.
Is there an SDK, and what about limits?
There is no SDK yet; the calling endpoints are plain REST you call from any language, with typed libraries on the roadmap. Calls run concurrently, so throughput scales with your account rather than being dialed strictly one after another.
What does calling cost?
A flat $0.08 per minute of voice, pay-as-you-go, premium model included, with your own carrier underneath. No credits and no per-call platform fee; you pay for the minutes a call actually lasts.
Place your first call today
Fire one from an event, or dispatch a list. One API key, results on every call.