No SDK to wait for. Just REST.
We will be straight with you: Nixflex does not have a published SDK yet. It is a REST API you call from any language today, and typed libraries are on the roadmap. The same request that creates an agent works in curl, Python, Node or Go, with nothing to install from us.
curl -X POST https://api.nixflex.com/v1/agents \
-H "Authorization: Bearer nxf_live:nxfs_live" \
-d '{ "name": "Front desk" }'Why we are telling you this up front
It would be easy to ship a thin wrapper and call it an SDK. Developers see through that, and a wrapper that lags the API is worse than none. The truth is more useful: the Nixflex surface is small and consistent enough that you do not need a library to be productive. You send an authenticated request, you read JSON back, and you are building.
The whole surface is a handful of endpoints
There is not much to wrap. Agents, numbers, calls, SMS and keys are the entire API, each with predictable verbs and JSON bodies. That is why REST is enough on its own.
POST /v1/agentsPOST /v1/phone-numbersPOST /v1/calls/outboundGET /v1/callsPOST /v1/smsGET /v1/keysTyped libraries are on the roadmap
We are building typed client libraries for the common languages, and we would rather not name a date we might miss. When they land they will sit alongside REST, not replace it, so anything you build today keeps working and you can adopt a client later at your own pace. Until then, the REST API is stable and complete, and generating your own thin client from it takes an afternoon.
Start with the API
The reference has every endpoint, payload and response, with the auth header spelled out. It is the same surface a future SDK will wrap, so time spent learning it is not wasted.
Read the API reference, or the Voice AI API and Webhooks pages. Coming from another platform? Nixflex is a modern alternative to Retell, Vapi and Bland. Compare them →
Developer FAQ
Does Nixflex have an SDK?
Not a published one yet. Nixflex is a REST API today, and typed client libraries are on the roadmap. We are telling you that plainly rather than shipping a thin wrapper to tick a box, because the endpoints are simple enough that most teams are up and running with the HTTP client they already have.
So how do I integrate without an SDK?
The same way you call any REST API. Send an authenticated HTTP request to an endpoint and read the JSON back. The request to create an agent is a few lines in curl, Python, Node or Go, and none of it depends on a library from us. If your language can make an HTTPS request, it can drive Nixflex.
Is REST enough for production, or will I hit a wall?
It is enough. Agents, numbers, calls, SMS and keys are all plain REST, results come back as JSON, and events arrive by webhook. A common pattern across the industry is to start on REST and stay there; you only reach for more when you need low-level streaming control, which most voice-agent products never do.
When is the SDK coming, and which languages?
Typed libraries are on the roadmap, with the common languages first. We would rather not name a date we might miss, so the honest answer is that they are coming and the REST API is stable enough that adopting one later will not force you to rewrite your integration.
Will a future SDK break my REST integration?
No. An SDK is a convenience layer over the same endpoints, added alongside REST rather than replacing it. Anything you build against the API today keeps working, and you can move to a typed client at your own pace if you want to.
Can I generate my own client from the API?
Yes. Because the surface is small and consistent, plenty of teams wrap the few endpoints they use into a tidy internal module in an afternoon. You are never blocked waiting on us for a client in your language.
What does it cost to build on?
A flat $0.08 per minute of voice, pay-as-you-go, premium model included, with your own carrier underneath. No credits and no platform fee to start, whether you call the API by hand or through a client you have wrapped yourself.
Build on the REST API today
No package to install, no SDK to wait for. Grab a key and send your first request.