Update Voice Agent

Overview

Update an existing Voice agent’s configuration including voice settings, conversation behavior, voicemail handling, and AI behavior. All parameters from Create Voice Agent can be updated.

This endpoint is for Voice agents only. For SMS agents, see Update SMS Agent.For updating tools (function calling, transfers, etc.), use Update Voice Agent Tools.

Authentication

X-API-Key

string

required

Your Teli API key

Path Parameters

agent_id

string

required

The unique identifier of the Voice agent to update

Request Body

All fields are optional. Only include the fields you want to update.

Basic Settings

agent_name

string

Display name for the agent

starting_message

string

First message spoken when call connects. Supports {{first_name}}, {{last_name}}

prompt

string

AI behavior instructions defining personality and conversation goals

Voice Configuration

voice_id

string

Voice ID for text-to-speech. See List Voices for options.

voice_temperature

number

default:"1"

Voice stability. Range: 0 (stable) to 2 (varied)

voice_speed

number

default:"1"

Speech rate. Range: 0.5 (slow) to 2 (fast)

volume

number

default:"1"

Agent volume. Range: 0 (quiet) to 2 (loud)

Language

language

string

default:"en-US"

Speech recognition language

Supported languages:

en-US (English - US)
en-GB (English - UK)
es-ES (Spanish - Spain)
es-419 (Spanish - Latin America)
fr-FR (French)
de-DE (German)
ja-JP (Japanese)
zh-CN (Chinese)
multi (Multilingual)

Conversation Behavior

responsiveness

number

default:"1"

How quickly agent responds. Range: 0 (slower) to 1 (faster)

interruption_sensitivity

number

default:"1"

How easily user can interrupt. Range: 0 (hard) to 1 (easy)

enable_backchannel

boolean

default:"false"

Enable conversational interjections (“yeah”, “uh-huh”)

backchannel_frequency

number

default:"0.8"

How often to interject. Range: 0 (rarely) to 1 (frequently)

backchannel_words

array

Custom backchannel words. Example: ["right", "I see", "got it"]

Ambient Sound

ambient_sound

string

Background audio for realism

Options:

null - No ambient sound
coffee-shop - Café atmosphere
convention-hall - Echo, crowd noise
summer-outdoor - Cicadas, nature
mountain-outdoor - Birds, wind
static-noise - Light static
call-center - Office background

ambient_sound_volume

number

default:"1"

Ambient sound level. Range: 0 to 2

Voicemail Detection

enable_voicemail_detection

boolean

default:"true"

Automatically detect voicemail

voicemail_message

string

Message to leave on voicemail. Empty string = hangup immediately

voicemail_detection_timeout_ms

number

default:"30000"

Detection timeout in milliseconds. Range: 5000 to 180000

Reminder & Silence Settings

reminder_trigger_ms

number

default:"10000"

Time (ms) to wait before reminding silent user

reminder_max_count

number

default:"1"

Maximum reminders before ending call. 0 = disabled

end_call_after_silence_ms

number

default:"90000"

End call after this much silence (ms). Minimum: 10000

Call Settings

max_call_duration_ms

number

default:"3600000"

Maximum call length in milliseconds. Range: 60000 to 7200000

begin_message_delay_ms

number

default:"0"

Delay before speaking (ms). Range: 0 to 5000

ring_duration_ms

number

default:"30000"

Ring timeout for outbound calls (ms). Range: 5000 to 90000

Speech Recognition

stt_mode

string

default:"fast"

Speech-to-text mode: fast or accurate

vocab_specialization

string

default:"general"

Vocabulary focus: general or medical

boosted_keywords

array

Words to boost recognition. Example: ["Acme", "TurboWidget"]

normalize_for_speech

boolean

default:"false"

Convert numbers/dates to spoken form

allow_user_dtmf

boolean

default:"true"

Allow keypad input (press 1, press 2, etc.)

denoising_mode

string

default:"noise-cancellation"

Audio cleanup: noise-cancellation or noise-and-background-speech-cancellation

Knowledge Base

knowledge_base_ids

array

Link knowledge bases for RAG retrieval. Example: ["kb_abc123"]

kb_config

object

Knowledge base retrieval settings

kb_config Example

{
  "top_k": 3,           // Chunks to retrieve (1-10)
  "filter_score": 0.6   // Similarity threshold (0-1)
}

Data Extraction (Post-Call Analysis)

Automatically extract custom data from call transcripts after each call ends.

extraction_fields

array

List of field names to extract from conversations. Simple string array.Example: ["credit_score", "loan_amount", "annual_income", "interested"]Extracted data is accessible via GET /v1/voice/calls//extractions.

post_call_analysis_data

array

Advanced: Define custom fields with specific types. Use extraction_fields for simpler configuration.String Type - Extract free-form text:

{ "type": "string", "name": "customer_name", "description": "Full name of customer" }

Enum Type - Extract from predefined choices:

{ "type": "enum", "name": "interest_level", "description": "Interest level", "choices": ["high", "medium", "low"] }

Boolean Type - Extract true/false:

{ "type": "boolean", "name": "scheduled_callback", "description": "Agreed to callback" }

Number Type - Extract numeric values:

{ "type": "number", "name": "budget", "description": "Stated budget amount" }

Privacy & Storage

data_storage_setting

string

default:"everything"

What data to store

Options:

everything - Full transcripts, recordings, logs
everything_except_pii - Scrub PII before storing
basic_attributes_only - No transcripts/recordings

Request Examples

Update Voice Settings

curl -X PATCH "https://api.teli.ai/v1/agents/agent_voice123" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "voice_speed": 0.9,
    "voice_temperature": 0.8,
    "responsiveness": 0.7,
    "interruption_sensitivity": 0.9
  }'

Update Conversation Behavior

curl -X PATCH "https://api.teli.ai/v1/agents/agent_voice123" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "enable_backchannel": true,
    "backchannel_frequency": 0.6,
    "backchannel_words": ["right", "I see", "got it", "okay"],
    "ambient_sound": "call-center",
    "ambient_sound_volume": 0.5
  }'

Update Voicemail Settings

curl -X PATCH "https://api.teli.ai/v1/agents/agent_voice123" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "enable_voicemail_detection": true,
    "voicemail_message": "Hi {{first_name}}, this is Sarah from Acme Corp. Please call us back at 555-1234.",
    "voicemail_detection_timeout_ms": 25000
  }'

Update AI Prompt & Knowledge Base

curl -X PATCH "https://api.teli.ai/v1/agents/agent_voice123" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "You are a helpful customer support agent. Be friendly and professional. Answer questions using the knowledge base when available.",
    "knowledge_base_ids": ["kb_abc123", "kb_def456"],
    "kb_config": {
      "top_k": 5,
      "filter_score": 0.7
    }
  }'

Update Post-Call Analysis

curl -X PATCH "https://api.teli.ai/v1/agents/agent_voice123" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "post_call_analysis_data": [
      {
        "type": "string",
        "name": "customer_name",
        "description": "The full name of the customer"
      },
      {
        "type": "enum",
        "name": "interest_level",
        "description": "How interested is the customer",
        "choices": ["very_interested", "somewhat_interested", "not_interested"]
      },
      {
        "type": "boolean",
        "name": "scheduled_callback",
        "description": "Whether the customer agreed to a callback"
      },
      {
        "type": "number",
        "name": "budget",
        "description": "The customer stated budget amount"
      }
    ],
    "post_call_analysis_model": "gpt-4.1-mini"
  }'

Comprehensive Update

{
  "agent_name": "Premium Support Agent",
  "starting_message": "Hello {{first_name}}, thank you for calling Acme Support. How can I help you today?",
  "prompt": "You are a senior support specialist...",
  "voice_speed": 0.95,
  "voice_temperature": 0.7,
  "responsiveness": 0.8,
  "interruption_sensitivity": 0.9,
  "enable_backchannel": true,
  "backchannel_frequency": 0.5,
  "ambient_sound": "call-center",
  "reminder_max_count": 2,
  "end_call_after_silence_ms": 120000,
  "max_call_duration_ms": 1800000,
  "voicemail_message": "Hi, please call us back.",
  "knowledge_base_ids": ["kb_products", "kb_faq"]
}

Response

Success Response

{
  "success": true,
  "agent_id": "agent_voice123",
  "message": "Agent updated successfully",
  "updated": {
    "voice_settings": true,
    "ai_behavior": true,
    "agent_info": true
  }
}

success

boolean

Indicates successful update

agent_id

string

The updated agent’s unique identifier

updated.voice_settings

boolean

Whether voice/call settings were updated

updated.ai_behavior

boolean

Whether AI prompt/tools/knowledge base was updated

updated.agent_info

boolean

Whether agent metadata was updated

Error Responses

{
  "success": false,
  "error": "Agent not found"
}

Use Case Presets

Cold Calling / Sales

{
  "voice_speed": 1,
  "voice_temperature": 1,
  "responsiveness": 0.8,
  "interruption_sensitivity": 0.7,
  "enable_backchannel": true,
  "voicemail_message": "Hi {{first_name}}, this is calling from [Company]. Please call us back."
}

Customer Support

{
  "voice_speed": 0.9,
  "voice_temperature": 0.8,
  "responsiveness": 0.6,
  "interruption_sensitivity": 0.9,
  "enable_backchannel": true,
  "backchannel_frequency": 0.7,
  "ambient_sound": "call-center",
  "reminder_max_count": 3
}

Appointment Reminders

{
  "voice_speed": 1.1,
  "voice_temperature": 0.5,
  "responsiveness": 1,
  "max_call_duration_ms": 300000,
  "voicemail_message": "Hi {{first_name}}, this is a reminder about your appointment."
}

Best Practices

Test changes: Test with a single call before updating production agents

Start conservative: Begin with default values and adjust gradually

Match voice to persona: Choose voice settings that match your agent’s personality

Enable backchannel for long calls: Makes conversations feel more natural

Set appropriate timeouts: Adjust silence and reminder settings for your use case

Notes

Updates take effect immediately for new calls
Active calls continue with previous settings
Some settings (like voice_id) may take a few seconds to propagate
Agent type cannot be changed from Voice to SMS

Create Voice Agent - Create a new voice agent
Update Voice Agent Tools - Manage function calling, transfers, etc.
Get Agent - Retrieve agent details
List Voices - Browse available voices
Create Knowledge Base - Create KB for RAG

Getting Started

Organizations

Users

AI Agents

Knowledge Base

Contacts & Leads

SMS Campaigns

Messages

SMS Phone Numbers

Voice Campaigns

Phone Numbers

Voices

Call History

Analytics

Do Not Call (DNC)

SMS Data Extraction

10DLC SMS Registration

Reference

​Overview

​Authentication

​Path Parameters

​Request Body

​Basic Settings

​Voice Configuration

​Language

​Conversation Behavior

​Ambient Sound

​Voicemail Detection

​Reminder & Silence Settings

​Call Settings

​Speech Recognition

​Knowledge Base

​Data Extraction (Post-Call Analysis)

​Privacy & Storage

​Request Examples

​Update Voice Settings

​Update Conversation Behavior

​Update Voicemail Settings

​Update AI Prompt & Knowledge Base

​Update Post-Call Analysis

​Comprehensive Update

​Response

​Success Response

​Error Responses

​Use Case Presets

​Cold Calling / Sales

​Customer Support

​Appointment Reminders

​Best Practices

​Notes

​Related Endpoints

Overview

Authentication

Path Parameters

Request Body

Basic Settings

Voice Configuration

Language

Conversation Behavior

Ambient Sound

Voicemail Detection

Reminder & Silence Settings

Call Settings

Speech Recognition

Knowledge Base

Data Extraction (Post-Call Analysis)

Privacy & Storage

Request Examples

Update Voice Settings

Update Conversation Behavior

Update Voicemail Settings

Update AI Prompt & Knowledge Base

Update Post-Call Analysis

Comprehensive Update

Response

Success Response

Error Responses

Use Case Presets

Cold Calling / Sales

Customer Support

Appointment Reminders

Best Practices

Notes

Related Endpoints