Custom Functions
Your API, mid-conversation.
Most platforms hand you data after the call ends. Nixflex calls your API while the caller is still on the line - looks up the order, checks the stock, fetches the record - and speaks the answer seconds later.
14 variables, every request
Caller number, timezone-correct dates, call direction - and caller_history: summaries of this caller’s past calls, so your endpoint recognises returning customers automatically.
Failure never breaks the call
Timeout, 500, network error - the agent is told the function failed and apologises or transfers naturally. Your API being down never strands a caller in silence.
Built for real APIs
HTTPS with your auth headers, {{variable}} substitution in URLs for REST endpoints, per-function timeouts from 1 to 45 seconds, and a one-click test button before you go live.
THE ONE FIELD THAT MATTERS MOST
The agent decides when to fire your function from its description - which it re-reads every turn. Write it as instructions, starting with “Use when…”: “Use when the caller asks about delivery, order status, or where their order is.” Vague descriptions mean the function never fires - precise ones fire every time.
Your API, on the phone