Update Assistant

This endpoint allows you to update the configuration of an existing AI assistant. All fields are optional – only the fields provided will be updated. For detailed field descriptions and options, see Create Assistant.

Path Parameter

integer

required

The unique identifier of the assistant to be updated

Request Body

Core Fields

name

string

The name of the assistant (max. 255 characters)

voice_id

integer

The voice ID to be used for the assistant. Use the Get Voices endpoint with the mode parameter to get voices compatible with your engine mode.

language_id

integer

The language ID for the assistant. Use the Get Languages endpoint to retrieve available languages.

type

string

The assistant type. Options: inbound, outbound

mode

string

The engine mode. Options: pipeline, multimodal, dualplex

Changing the mode resets mode-specific settings to their default values for the new mode.

timezone

string

The timezone for the assistant (e.g., “Europe/Berlin”, “America/New_York”)

initial_message

string

The initial message the assistant will speak at call start (max. 200 characters)

system_prompt

string

The system prompt defining the assistant’s behaviour and personality

Mode-Specific Fields

llm_model_id

integer

The LLM model ID to use. Only applicable in pipeline mode.Use the Get Models endpoint to retrieve available models.

multimodal_model_id

integer

The multimodal model ID. Applicable only in multimodal and dualplex modes.Use the Get Models endpoint to retrieve available multimodal models.

chat_llm_fallback_id

integer

Fallback LLM model ID for tool calls in multimodal/dualplex modes. Set to null to remove.

turn_detection_threshold

number

Sensitivity of speaker turn detection for multimodal/dualplex modes (0-1). Set to null for automatic.

Secondary Languages

secondary_language_ids

integer[]

Array of additional language IDs the assistant can speak. Replaces existing secondary languages. Pass an empty array [] to remove all secondary languages.

"secondary_language_ids": [2, 3, 4]

Knowledgebase Settings

knowledgebase_id

integer

The ID of the knowledgebase to link. Set to null to remove.

knowledgebase_mode

string

How the knowledgebase should be used. Options:

function_call - AI uses a function to search (required for multimodal/dualplex)
prompt - knowledge is injected into the prompt (pipeline only)

Phone Number

phone_number_id

integer

The ID of a phone number to assign. Set to null to unassign. Must belong to your account.

For inbound assistants, the phone number cannot be a caller ID type and must not already be assigned to another inbound assistant.

Custom Mid-Call Tools

tool_ids

integer[]

Array of custom mid-call tool IDs to synchronize. Replaces all existing tool assignments. Pass an empty array [] to remove all tools. Each tool must belong to your account.

"tool_ids": [1, 5, 12]

Built-in Tools

tools

array

Array of built-in tools. Replaces all existing built-in tools. Pass an empty array [] to remove all tools.

Show Tool Types

call_transfer - Transfer the call to another phone number

phone_number (required): Phone number for transfer
description: When to transfer the call
custom: If true, AI can dynamically determine the transfer number
timezone: Timezone for the transfer’s availability
warm_transfer: Message to the customer before transfer (default: false)
warm_transfer_message: Prompt what AI should say before transfer (e.g., “Let the customer know the call is being transferred.”)

warm_call_transfer - Warm transfer with supervisor briefing

supervisor_phone (required): Phone number for warm transfer (e.g., “+14155552001”). For custom_sip, use SIP address or internal extension.
outbound_phone_id (required): ID of the phone number used to call the supervisor. See Get Phone Numbers.
description (required): When to transfer – when AI should trigger the warm transfer (e.g., “Transfer to human agent when customer wants to speak to a real person.”)
custom_sip: Custom SIP address or internal extension instead of phone number (default: false)
caller_id_mode: Which number the supervisor sees. Options: outbound_number (default), customer_number, custom
custom_caller_id: Custom number for supervisor. Only with caller_id_mode: custom.
hold_music: Hold music. Options: hold_music (default), none
hold_music_volume: Volume of hold music 0–100 (default: 80)
hold_message: Message to caller before hold (default: “Please wait while I connect you to an agent.”)
summary_instructions: Instruction on how AI should brief supervisor (default summary: Who is calling, why, why a human is needed.)
briefing_initial_message: AI’s initial message to supervisor (default: “Hello! I have a caller who needs assistance. May I briefly explain the situation?”)
connected_message: Message to caller after connecting with supervisor (default: “You are now connected to an agent.”)

end_call - Programmatically end the call

description: When AI should end the call

dtmf_input - Send DTMF tones (keypad input)

description: When DTMF input is used (e.g., IVR navigation)

collect_keypad - Collect keypad input from caller

timeout: Wait time in seconds, 1–30 (default: 5)
stop_key: Key to end input. Options: # (default), *

calendar_integration - Schedule appointments via Cal.com

calcom_api_key (required): Your Cal.com API key
calcom_event_slug (required): Cal.com event type slug
calcom_team_slug: Team slug if the event belongs to a Cal.com team
calcom_endpoint: API region. Options: us (default – https://api.cal.com), eu (https://api.cal.eu), custom (uses calcom_custom_endpoint)
calcom_custom_endpoint: Custom Cal.com API URL. Only for calcom_endpoint: custom (e.g., https://my-calcom-instance.com).
calcom_booking_fields: Array of custom booking fields. Each field: slug, type, label, optionally required, options for Select.
description: When to offer appointment booking

"tools": [
  {"type": "dtmf_input", "description": "Navigate IVR as needed"},
  {
    "type": "warm_call_transfer",
    "supervisor_phone": "+1234567890",
    "outbound_phone_id": 7,
    "description": "Transfer to a human agent when the customer wants to speak to a real person.",
    "custom_sip": false,
    "caller_id_mode": "outbound_number",
    "hold_music": "hold_music",
    "hold_music_volume": 80,
    "hold_message": "Please wait while I connect you to an agent.",
    "summary_instructions": "Briefly from your perspective: Who is calling, why, why a human is needed. 2–3 sentences.",
    "briefing_initial_message": "Hello! I have a caller who needs assistance. May I briefly explain the situation?",
    "connected_message": "You are now connected to an agent."
  },
  {"type": "collect_keypad", "timeout": 5, "stop_key": "#"},
  {"type": "end_call", "description": "End call when done"}
]

Speech and TTS Settings

tts_emotion_enabled

boolean

Whether emotional text-to-speech synthesis is enabled

voice_stability

number

Voice stability setting (0-1). Higher = more consistent voice

voice_similarity

number

Voice similarity setting (0-1). Higher = closer to original voice

speech_speed

number

Speech speed multiplier (0.7-1.2)

llm_temperature

number

LLM temperature setting (0-1). Lower = more deterministic

synthesizer_provider_id

integer

Custom TTS provider ID. Set to null to use the system default voice. See Get Synthesizer Providers.

transcriber_provider_id

integer

Custom STT provider ID. Pipeline mode only. Set to null to use the system default voice. See Get Transcriber Providers.

Call Behavior Settings

allow_interruptions

boolean

Whether caller interruptions are allowed.

Cannot be disabled in multimodal and dualplex modes.

fillers

boolean

Whether filler audio should be used during processing.

Available only in pipeline mode.

filler_config

object

Custom filler profiles per category. Replaces the existing filler configuration. Each category is an array of short phrases.

positive: Fillers for affirmative responses
negative: Fillers for negative/neutral responses
question: Fillers when processing a question
neutral: Fillers for neutral confirmations

"filler_config": {
  "positive": ["Great!", "Perfect!"],
  "negative": ["Hmm.", "Understood."],
  "question": ["Good question.", "One moment."],
  "neutral": ["Okay.", "Noted."]
}

record

boolean

Whether the call should be recorded

enable_noise_cancellation

boolean

Whether noise cancellation should be enabled

wait_for_customer

boolean

If true, the assistant waits for the customer to speak first

Timing Settings

max_duration

integer

Maximum call duration in seconds (20-1200)

max_silence_duration

integer

Maximum silence duration before re-engagement in seconds (1-360)

max_initial_silence_duration

integer

Maximum silence at the start of the call before termination (1-120 seconds). Set to null to disable.

ringing_time

integer

Maximum ringing time before aborting (1-60 seconds)

Re-Engagement Settings

reengagement_interval

integer

Interval for re-engagement in seconds (7-600)

reengagement_prompt

string

Custom prompt for re-engagement messages (max. 1000 characters). Set to null to use the default.

Voicemail Settings

end_call_on_voicemail

boolean

Whether to end the call when voicemail is detected

voice_mail_message

string

Message to leave on voicemail before hanging up (max. 1000 characters). Set to null to disable.

Endpoint Detection

endpoint_type

string

Type of voice activity detection. Options: vad, ai

endpoint_sensitivity

number

Endpoint sensitivity level (0-5)

interrupt_sensitivity

number

Interruption sensitivity level (0-5)

min_interrupt_words

integer

Minimum number of words before interruption is allowed (0-10). Set to null to disable.

Ambient Sound

ambient_sound

string

Background ambient sound. Options: off, office, city, forest, crowded_room, cafe, nature

ambient_sound_volume

number

Volume of the ambient sound (0-1)

Webhook Configuration

is_webhook_active

boolean

Whether webhook notifications are enabled

webhook_url

string

The webhook URL for post-call notifications. Set to null to remove.

send_webhook_only_on_completed

boolean

Whether webhooks should be sent only for successfully completed calls (not on failed/no-answer)

include_recording_in_webhook

boolean

Whether the recording URL should be included in the webhook payload

Post-Call Evaluation

post_call_evaluation

boolean

Whether AI-based post-call evaluation is enabled

post_call_schema

array

Schema definition for extracting post-call data. Replaces the existing schema.

Show post_call_schema Properties

name

string

required

Field name (3-16 characters, lowercase, alphanumeric and underscores only)

type

string

required

Data type. Options: string, number, bool

description

string

required

Description of what this field represents (3-255 characters)

Variables

variables

object

Key-value pairs for custom variables. Replaces all existing variables.

"variables": {
  "company_name": "Acme Corp",
  "product": "Premium Widget"
}

Example Requests

Update Basic Settings

{
  "name": "Updated Assistant Name",
  "initial_message": "Hello! How can I help you today?",
  "max_duration": 900
}

Switch to Multimodal Mode

{
  "mode": "multimodal",
  "voice_id": 41,
  "multimodal_model_id": 1,
  "chat_llm_fallback_id": 2,
  "knowledgebase_mode": "function_call"
}

Update Tools and Knowledgebase

{
  "tool_ids": [1, 5, 12],
  "knowledgebase_id": 3,
  "knowledgebase_mode": "prompt"
}

Update Re-Engagement and Voicemail

{
  "reengagement_interval": 15,
  "reengagement_prompt": "Are you still there? I'm here to help.",
  "end_call_on_voicemail": true,
  "voice_mail_message": "Hello, please call us back at your earliest convenience."
}

Remove Optional Settings

{
  "phone_number_id": null,
  "webhook_url": null,
  "tool_ids": [],
  "secondary_language_ids": []
}

Response

message

string

Success message confirming the assistant update

data

object

Show Properties

integer

The unique ID of the updated assistant

name

string

The assistant’s name

status

string

The current status of the assistant

type

string

The type (inbound or outbound)

mode

string

The engine mode (pipeline, multimodal, or dualplex)

{
  "message": "Assistant updated successfully",
  "data": {
    "id": 789,
    "name": "Updated Sales Assistant",
    "status": "active",
    "type": "outbound",
    "mode": "pipeline"
  }
}

Notes

Only the fields you provide in the request body will be updated
To remove optional fields, explicitly set them to null
To clear arrays (tools, secondary languages), pass an empty array []
The assistant must belong to the authenticated user
Use the Get Voices endpoint with the mode parameter to get compatible voices
For multimodal/dualplex modes, knowledgebase_mode must be set to function_call
In multimodal/dualplex modes, interruptions (allow_interruptions) cannot be disabled
Changing mode resets mode-specific settings (LLM model, multimodal model, providers)

API Reference

AI Assistants

Leads

Campaigns

Mid Call Tools

AI Chatbot

AI Replies

Knowledgebases

SMS

WhatsApp

Phone Numbers

Calls

Webhooks

​Path Parameter

​Request Body

​Core Fields

​Mode-Specific Fields

​Secondary Languages

​Knowledgebase Settings

​Phone Number

​Custom Mid-Call Tools

​Built-in Tools

​Speech and TTS Settings

​Call Behavior Settings

​Timing Settings

​Re-Engagement Settings

​Voicemail Settings

​Endpoint Detection

​Ambient Sound

​Webhook Configuration

​Post-Call Evaluation

​Variables

​Example Requests

​Update Basic Settings

​Switch to Multimodal Mode

​Update Tools and Knowledgebase

​Update Re-Engagement and Voicemail

​Remove Optional Settings

​Response

​Notes

Path Parameter

Request Body

Core Fields

Mode-Specific Fields

Secondary Languages

Knowledgebase Settings

Phone Number

Custom Mid-Call Tools

Built-in Tools

Speech and TTS Settings

Call Behavior Settings

Timing Settings

Re-Engagement Settings

Voicemail Settings

Endpoint Detection

Ambient Sound

Webhook Configuration

Post-Call Evaluation

Variables

Example Requests

Update Basic Settings

Switch to Multimodal Mode

Update Tools and Knowledgebase

Update Re-Engagement and Voicemail

Remove Optional Settings

Response

Notes