Quickstart

You will need a SIP trunk you already have. Wixzel Voice does not resell telephony, so your carrier rates stay yours.

Connect your SIP trunk

Your carrier’s credentials. The password is stored encrypted and is never returned by the API again — including to you.

curl https://api.voice.wixzel.com/v1/sip-trunks \
  -H "Authorization: Bearer $WIXZEL_API_KEY" \
  -d '{
    "name": "My carrier",
    "host": "sip.carrier.example",
    "username": "acct123",
    "password": "…"
  }'

curl .../v1/phone-numbers \
  -d '{
    "phone_number": "+14155550100",
    "sip_trunk_id": "st_01HXYZ"
  }'

Give it an inbound_agent_id and inbound calls to this number are answered automatically.

Create an agent

Name the models you want. Call GET /v1/engines for what is available and what each costs.

curl .../v1/agents \
  -d '{
    "name": "Support",
    "system_prompt": "You are a concise support agent.",
    "opening_message": "Hi, how can I help?",
    "voice": {
      "stt": { "model": "deepgram/nova-3" },
      "llm": { "model": "openrouter/gpt-4o-mini" },
      "tts": { "model": "elevenlabs/eleven_turbo_v2_5" }
    }
  }'

opening_message is required. An agent without one answers in silence, and we would rather ask than invent its first words.

Place a call

curl .../v1/calls \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
    "to": "+14155551234",
    "agent_id": "ag_01HXYZ"
  }'

Idempotency-Key is required here. A network timeout tells you nothing about whether the call was placed — without the key your only options are retrying and dialling twice, or not retrying and losing the call.

See what it cost

Every micro debited against a call is explained by a usage row, so you never have to reconcile a total by hand.

curl ".../v1/usage/events?session_id=sip-4f2a"

Component	Model	Quantity	Cost
`stt`	deepgram/nova-3	187 s	$0.0336
`llm`	openrouter/gpt-4o-mini	8.2k tokens	$0.0031
`tts`	elevenlabs/eleven_turbo_v2_5	1.4k chars	$0.0980
`platform_fee`	orchestration	4 min	$0.0480
		Total	$0.2714

Running out of credit

Credit is reserved before the call is placed, so an underfunded account is refused with 402 before any resources are allocated. Mid-call, the agent warns your caller about a minute out and speaks a closing line before hanging up. It does not drop the line mid-sentence.

Getting started

Concepts

API reference

See what it cost

Running out of credit

​See what it cost

​Running out of credit

See what it cost

Running out of credit