Assistants

An assistant is one AI voice agent: a system prompt, a voice, the tools it may call, and the settings that govern a call. Everything a phone number or a campaign dials is an assistant.

Endpoints

Endpoint	Purpose
`POST /assistant`	Create an assistant
`POST /assistant/list`	List your assistants, paged and searchable
`GET /assistant/{id}`	One assistant, with its complete configuration
`PATCH /assistant/{id}`	Change the name, type or any part of the configuration
`PUT /assistant/{id}`	Replace the whole configuration
`DELETE /assistant/{id}`	Delete an assistant

The workspace comes from your API key, so no endpoint asks you for a workspace id.

Listing is a POST because a list query is a document — page, size and a search term, typed as themselves rather than coerced from a query string. It reads, and changes nothing.

The assistant object

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "workspace_id": "123e4567-e89b-12d3-a456-426614174000",
  "agent_name": "Customer Support",
  "agent_type": "Single Prompt",
  "config": { "…": "see below" },
  "sip_uri": "sip:a1b2c3@sip.verbeo.ai",
  "has_cal_integration": false,
  "created_at": "2026-01-15T10:30:00.000Z",
  "updated_at": "2026-01-22T14:00:00.000Z"
}

string

required

UUID of the assistant.

string

required

Display name, 1–255 characters.

string

required

Prompt style. "Single Prompt" is the only supported value today.

object

required

The configuration document — see below.

string

The assistant’s own inbound SIP URI, when SIP is provisioned. Point a carrier at it to route calls here.

string

required

ISO 8601 timestamp.

string

required

ISO 8601 timestamp of the last change.

The configuration document

config is where the assistant’s behaviour lives. Send only the parts you care about — anything you leave out is filled in with the same defaults the dashboard gives a new assistant, and the completed document is what comes back. To change it later, PATCH merges what you send into it, and PUT replaces it.

{
  "systemPrompt": "You are a friendly support agent for Acme…",
  "voice": { "voiceId": "Charon" },
  "toolIds": ["4f1c…"],
  "fileSearchStoreIds": [],
  "nativeTools": {
    "end_call": { "enabled": true },
    "transfer_call": {
      "enabled": true,
      "mode": "static",
      "staticDestination": "+15551234567"
    }
  },
  "settings": {
    "initialMessage": { "enabled": true },
    "maxCallDuration": 10,
    "endCallOnSilence": true,
    "silenceTimeoutMinutes": 2,
    "voicemailDetection": { "enabled": true, "action": "hangup" },
    "thinkingLevel": "medium",
    "webhookUrl": "",
    "postCallAnalysis": { "enabled": false, "fields": [] }
  }
}

string

The instructions the assistant follows. Supports {{variable}} placeholders filled in per call.

string

default:"gemini-3.8-live"

Every assistant runs on Gemini 3.8 Live, so this is always stored as gemini-3.8-live, whatever a request sends.

string

default:"Charon"

One of: Zephyr, Puck, Charon, Kore, Fenrir, Leda, Orus, Aoede, Callirrhoe, Autonoe, Enceladus, Iapetus, Umbriel, Algieba, Despina, Erinome, Algenib, Rasalgethi, Laomedeia, Achernar, Alnilam, Schedar, Gacrux, Pulcherrima, Achird, Zubenelgenubi, Vindemiatrix, Sadachbia, Sadaltager, Sulafat. Anything else is rejected with VALIDATION_FAILED rather than quietly substituted — a voice you did not choose is an assistant that does not sound like the one you asked for.

string[]

Tools the assistant may call. Ids that do not belong to your workspace are dropped, and when two ids resolve to the same tool name only one is kept — a duplicate declaration is refused by the model at connect time, which would leave the call live and silent. The Tools endpoints add a tool’s id here when they create it and take it out when they delete it.

string[]

Knowledge bases the assistant may search. Each must belong to your workspace.

number

default:"10"

Hard ceiling on a call, in minutes: at most 30. A larger value is saved as 30.

number

default:"2"

How long a caller may stay silent before the assistant ends the call, in minutes. Only applies when endCallOnSilence is true.

object | boolean

default:"{ enabled: true, action: 'hangup' }"

Accepts true/false or { "enabled": true, "action": "hangup" }.

string

default:"medium"

Kept for compatibility, with no effect: every assistant runs on Gemini 3.8 Live, which always runs at minimal, whatever is stored here.

string

Where call events for this assistant are delivered. See Webhook events.

object

Structured fields to extract from each transcript. See Post-call analysis.

Native tools

nativeTools switches on the behaviour Verbeo implements for you. Each entry is three-state:

What you send	What happens
the key is absent	left exactly as it is
`{ "enabled": true, … }`	switched on, and provisioned if it does not exist yet
`{ "enabled": false }`	switched off; its settings are remembered for when you turn it back on

object

Lets the assistant hang up when the conversation is over. On by default for a new assistant — without it the assistant stays on the line, billing, after the caller has said goodbye.

object

Hands the call to a human. mode: "static" always dials staticDestination; mode: "dynamic" lets the assistant choose a number, guided by dynamicPrompt. Also takes transferType (cold or warm).

object

Sends a text message during the call. smsContentType: "static" sends smsStaticMessage verbatim; "prompt" lets the assistant compose it.

Fields you do not send are left unchanged on a tool that already exists, so you can retarget a transfer without restating the rest of it. The native tool endpoints change the same tools, under the tool’s own field names (transfer_call_destination for staticDestination), and also set what nativeTools cannot: a send_sms tool’s Twilio account and its timeout.

Authentication

Every endpoint takes a private workspace API key (vbr_…) as a Bearer token. Public widget keys (vbr_pub_…) are rejected with 403 FORBIDDEN — they ship inside web pages, where anyone can read them. See Authentication.

Overview

Tools

Phone Numbers

Calls

Campaigns

Webhooks

Assistants

Endpoints

The assistant object

The configuration document

Native tools

Authentication

​Endpoints

​The assistant object

​The configuration document

​Native tools

​Authentication

Endpoints

The assistant object

The configuration document

Native tools

Authentication