Retell AI Get Agent Versions API
The Get Agent Versions API from Retell AI — 1 operation(s) for get agent versions.
OpenAPI Specification
openapi: 3.0.3
info:
title: Retell SDK Add Community Voice Get Agent Versions API
version: 3.0.0
contact:
name: Retell Support
url: https://www.retellai.com/
email: support@retellai.com
license:
name: Apache 2.0
url: https://www.apache.org/licenses/LICENSE-2.0.html
servers:
- url: https://api.retellai.com
description: The production server.
security:
- api_key: []
tags:
- name: Get Agent Versions
paths:
/get-agent-versions/{agent_id}:
get:
description: Get all versions of an agent
operationId: getAgentVersions
parameters:
- in: path
name: agent_id
schema:
type: string
minLength: 1
example: 16b980523634a6dc504898cda492e939
required: true
description: Unique id of the agent versions to be retrieved.
responses:
'200':
description: Successfully retrieved all versions of an agent.
content:
application/json:
schema:
type: array
items:
$ref: '#/components/schemas/AgentResponse'
'400':
$ref: '#/components/responses/BadRequest'
'401':
$ref: '#/components/responses/Unauthorized'
'422':
$ref: '#/components/responses/UnprocessableContent'
'500':
$ref: '#/components/responses/InternalServerError'
tags:
- Get Agent Versions
components:
schemas:
CallPresetAnalysisData:
type: object
required:
- type
- name
description: System preset for post-call analysis (voice agents). Use in post_call_analysis_data to override prompts or mark fields optional.
properties:
type:
type: string
enum:
- system-presets
description: Identifies this item as a system preset.
name:
type: string
enum:
- call_summary
- call_successful
- user_sentiment
description: Preset identifier for voice agent analysis.
example: call_summary
description:
type: string
minLength: 1
description: Prompt or description for this preset.
required:
type: boolean
description: If false, this field is optional in the analysis. If true or unset, the field is required.
conditional_prompt:
type: string
description: Optional instruction to help decide whether this field needs to be populated. If not set, the field is always included.
VoicemailActionBridgeTransfer:
type: object
properties:
type:
type: string
enum:
- bridge_transfer
example: bridge_transfer
required:
- type
VoicemailActionPrompt:
type: object
properties:
type:
type: string
enum:
- prompt
example: prompt
text:
type: string
example: Summarize the call in 2 sentences.
description: The prompt used to generate the text to be spoken when the call is detected to be in voicemail.
required:
- type
- text
LanguageLegacy:
oneOf:
- $ref: '#/components/schemas/Language'
- type: string
enum:
- multi
example: en-US
description: Legacy single-string language format. Accepts any concrete locale from `Language`, plus the special scalar value `multi` for multilingual support. If unset, will use default value `en-US`.
Language:
type: string
example: en-US
enum:
- en-US
- en-IN
- en-GB
- en-AU
- en-NZ
- de-DE
- es-ES
- es-419
- hi-IN
- fr-FR
- fr-CA
- ja-JP
- pt-PT
- pt-BR
- zh-CN
- ru-RU
- it-IT
- ko-KR
- nl-NL
- nl-BE
- pl-PL
- tr-TR
- vi-VN
- ro-RO
- bg-BG
- ca-ES
- th-TH
- da-DK
- fi-FI
- el-GR
- hu-HU
- id-ID
- no-NO
- sk-SK
- sv-SE
- lt-LT
- lv-LV
- cs-CZ
- ms-MY
- af-ZA
- ar-SA
- az-AZ
- bs-BA
- cy-GB
- fa-IR
- fil-PH
- gl-ES
- he-IL
- hr-HR
- hy-AM
- is-IS
- kk-KZ
- kn-IN
- mk-MK
- mr-IN
- ne-NP
- sl-SI
- sr-RS
- sw-KE
- ta-IN
- ur-IN
- yue-CN
- uk-UA
description: Specifies what language (and dialect) the agent will operate in. For instance, selecting `en-GB` optimizes speech recognition for British English and indexes knowledge bases with English. If unset, will use default value `en-US`. This enum does not include the legacy scalar value `multi`.
AgentResponse:
allOf:
- type: object
required:
- agent_id
- version
properties:
agent_id:
type: string
example: oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD
description: Unique id of agent.
version:
type: integer
example: 0
description: Version of the agent.
base_version:
type: integer
nullable: true
example: 12
description: Version that this draft was based on. Null for initial versions.
assigned_tags:
type: array
items:
type: string
description: Tags assigned to this agent version. Preferred tag is listed first.
is_published:
type: boolean
example: false
description: Whether the agent is published.
- $ref: '#/components/schemas/AgentRequest'
required:
- response_engine
- voice_id
- type: object
required:
- last_modification_timestamp
properties:
last_modification_timestamp:
type: integer
example: 1703413636133
description: Last modification timestamp (milliseconds since epoch). Either the time of last update or creation if no updates available.
PIIConfig:
type: object
required:
- mode
- categories
properties:
mode:
type: string
enum:
- post_call
default: post_call
description: The processing mode for PII scrubbing. Currently only post-call is supported.
categories:
type: array
items:
type: string
enum:
- person_name
- address
- email
- phone_number
- ssn
- passport
- driver_license
- credit_card
- bank_account
- password
- pin
- medical_id
- date_of_birth
- customer_account_number
uniqueItems: true
default: []
description: List of PII categories to scrub from transcripts and recordings.
ResponseEngineRetellLm:
type: object
required:
- type
- llm_id
properties:
type:
type: string
enum:
- retell-llm
description: type of the Response Engine.
llm_id:
type: string
description: id of the Retell LLM Response Engine.
version:
type: number
example: 0
description: Version of the Retell LLM Response Engine.
nullable: true
ResponseEngine:
oneOf:
- $ref: '#/components/schemas/ResponseEngineRetellLm'
- $ref: '#/components/schemas/ResponseEngineCustomLm'
- $ref: '#/components/schemas/ResponseEngineConversationFlow'
ResponseEngineConversationFlow:
type: object
required:
- type
- conversation_flow_id
properties:
type:
type: string
enum:
- conversation-flow
description: type of the Response Engine.
conversation_flow_id:
type: string
description: ID of the Conversation Flow Response Engine.
version:
type: number
example: 0
description: Version of the Conversation Flow Response Engine.
nullable: true
VoicemailActionStaticText:
type: object
properties:
type:
type: string
enum:
- static_text
example: static_text
text:
type: string
example: Please give us a callback tomorrow at 10am.
description: The text to be spoken when the call is detected to be in voicemail.
required:
- type
- text
GuardrailConfig:
type: object
properties:
output_topics:
type: array
items:
type: string
enum:
- harassment
- self_harm
- sexual_exploitation
- violence
- defense_and_national_security
- illicit_and_harmful_activity
- gambling
- regulated_professional_advice
- child_safety_and_exploitation
uniqueItems: true
description: Selected prohibited agent topic categories to check. When agent messages contain these topics, they will be replaced with a placeholder message.
nullable: true
input_topics:
type: array
items:
type: string
enum:
- platform_integrity_jailbreaking
uniqueItems: true
description: Selected prohibited user topic categories to check. When user messages contain these topics, the agent will respond with a placeholder message instead of processing the request.
nullable: true
ResponseEngineCustomLm:
type: object
required:
- type
- llm_websocket_url
properties:
type:
type: string
enum:
- custom-llm
description: type of the Response Engine.
llm_websocket_url:
type: string
description: LLM websocket url of the custom LLM.
VoicemailAction:
oneOf:
- $ref: '#/components/schemas/VoicemailActionPrompt'
- $ref: '#/components/schemas/VoicemailActionStaticText'
- $ref: '#/components/schemas/VoicemailActionHangup'
- $ref: '#/components/schemas/VoicemailActionBridgeTransfer'
PostCallAnalysisData:
oneOf:
- $ref: '#/components/schemas/AnalysisData'
- $ref: '#/components/schemas/CallPresetAnalysisData'
description: Post-call analysis item (custom data or voice preset). Use for voice agent post_call_analysis_data; validates only call presets (call_summary, call_successful, user_sentiment).
AsrProvider:
type: string
enum:
- azure
- deepgram
- soniox
description: ASR provider name.
VoiceHandbookConfig:
type: object
description: Behavior presets for voice agents. All presets are available.
properties:
default_personality:
type: boolean
description: Professional call center rep baseline.
natural_filler_words:
type: boolean
description: Sprinkle natural speech fillers like "um", "you know" for a more human, conversational tone.
high_empathy:
type: boolean
description: Warm acknowledgment of caller concerns.
echo_verification:
type: boolean
description: Repeat back and confirm important details (voice only).
nato_phonetic_alphabet:
type: boolean
description: Spell using NATO phonetic alphabet style (voice only).
speech_normalization:
type: boolean
description: Convert numbers/dates/currency to spoken forms (voice only).
smart_matching:
type: boolean
description: Treat near-match similar words as same entity to reduce impact of transcription error (voice only).
ai_disclosure:
type: boolean
description: When asked, acknowledge being a virtual assistant.
scope_boundaries:
type: boolean
description: Stay within prompt/context scope, don't invent details.
BooleanAnalysisData:
type: object
required:
- type
- name
- description
properties:
type:
type: string
enum:
- boolean
description: Type of the variable to extract.
example: boolean
name:
type: string
description: Name of the variable.
example: is_converted
minLength: 1
description:
type: string
description: Description of the variable.
example: Whether the customer converted.
required:
type: boolean
description: Whether this data is required. If true and the data is not extracted, the call will be marked as unsuccessful.
conditional_prompt:
type: string
description: Optional instruction to help decide whether this field needs to be populated in the analysis. If not set, the field is always included. If required is true, this is ignored.
VoicemailActionHangup:
type: object
properties:
type:
type: string
enum:
- hangup
example: hangup
required:
- type
StringAnalysisData:
type: object
required:
- type
- name
- description
properties:
type:
type: string
enum:
- string
description: Type of the variable to extract.
example: string
name:
type: string
description: Name of the variable.
example: customer_name
minLength: 1
description:
type: string
description: Description of the variable.
example: The name of the customer.
examples:
type: array
items:
type: string
description: Examples of the variable value to teach model the style and syntax.
example:
- John Doe
- Jane Smith
required:
type: boolean
description: Whether this data is required. If true and the data is not extracted, the call will be marked as unsuccessful.
conditional_prompt:
type: string
description: Optional instruction to help decide whether this field needs to be populated in the analysis. If not set, the field is always included. If required is true, this is ignored.
IvrAction:
oneOf:
- $ref: '#/components/schemas/IvrActionHangup'
AnalysisData:
oneOf:
- $ref: '#/components/schemas/StringAnalysisData'
- $ref: '#/components/schemas/EnumAnalysisData'
- $ref: '#/components/schemas/BooleanAnalysisData'
- $ref: '#/components/schemas/NumberAnalysisData'
NumberAnalysisData:
type: object
required:
- type
- name
- description
properties:
type:
type: string
enum:
- number
description: Type of the variable to extract.
example: number
name:
type: string
description: Name of the variable.
example: order_count
minLength: 1
description:
type: string
description: Description of the variable.
example: How many the customer intend to order.
required:
type: boolean
description: Whether this data is required. If true and the data is not extracted, the call will be marked as unsuccessful.
conditional_prompt:
type: string
description: Optional instruction to help decide whether this field needs to be populated in the analysis. If not set, the field is always included. If required is true, this is ignored.
NullableLLMModel:
type: string
enum:
- gpt-4.1
- gpt-4.1-mini
- gpt-4.1-nano
- gpt-5
- gpt-5-mini
- gpt-5-nano
- gpt-5.1
- gpt-5.2
- gpt-5.4
- gpt-5.4-mini
- gpt-5.4-nano
- gpt-5.5
- claude-4.5-sonnet
- claude-4.6-sonnet
- claude-4.5-haiku
- gemini-2.5-flash-lite
- gemini-3.0-flash
- gemini-3.1-flash-lite
- null
nullable: true
description: Available LLM models for agents.
AgentRequest:
type: object
properties:
response_engine:
$ref: '#/components/schemas/ResponseEngine'
description: The Response Engine to attach to the agent. It is used to generate responses for the agent. You need to create a Response Engine first before attaching it to an agent.
example:
type: retell-llm
llm_id: llm_234sdertfsdsfsdf
version: 0
agent_name:
type: string
example: Jarvis
description: The name of the agent. Only used for your own reference.
nullable: true
version_description:
type: string
example: Customer support agent for handling product inquiries
description: Optional description of the agent version. Used for your own reference and documentation.
nullable: true
voice_id:
type: string
example: retell-Cimo
description: Unique voice id used for the agent. Find list of available voices and their preview in Dashboard.
voice_model:
type: string
enum:
- eleven_turbo_v2
- eleven_flash_v2
- eleven_turbo_v2_5
- eleven_flash_v2_5
- eleven_multilingual_v2
- eleven_v3
- sonic-3
- sonic-3-latest
- tts-1
- gpt-4o-mini-tts
- speech-02-turbo
- speech-2.8-turbo
- s1
- s2-pro
- null
description: Select the voice model used for the selected voice. Each provider has a set of available voice models. Set to null to remove voice model selection, and default ones will apply. Check out dashboard for more details of each voice model.
nullable: true
fallback_voice_ids:
type: array
items:
type: string
example:
- cartesia-Cimo
- minimax-Cimo
description: When TTS provider for the selected voice is experiencing outages, we would use fallback voices listed here for the agent. Voice id and the fallback voice ids must be from different TTS providers. The system would go through the list in order, if the first one in the list is also having outage, it would use the next one. Set to null to remove voice fallback for the agent.
nullable: true
voice_temperature:
type: number
example: 1
description: Controls how stable the voice is. Value ranging from [0,2]. Lower value means more stable, and higher value means more variant speech generation. Check the dashboard to see what provider supports this feature. If unset, default value 1 will apply.
voice_speed:
type: number
minimum: 0.5
maximum: 2
example: 1
description: Controls speed of voice. Value ranging from [0.5,2]. Lower value means slower speech, while higher value means faster speech rate. If unset, default value 1 will apply.
enable_dynamic_voice_speed:
type: boolean
example: true
description: If set to true, will enable dynamic voice speed adjustment based on the user's speech rate and conversation context. If unset, default value false will apply.
enable_dynamic_responsiveness:
type: boolean
example: true
description: If set to true, the agent will dynamically adjust how quickly it responds based on the user's speech rate and past turn-taking behavior in the call. If unset, default value false will apply.
volume:
type: number
example: 1
description: If set, will control the volume of the agent. Value ranging from [0,2]. Lower value means quieter agent speech, while higher value means louder agent speech. If unset, default value 1 will apply.
voice_emotion:
type: string
nullable: true
enum:
- calm
- sympathetic
- happy
- sad
- angry
- fearful
- surprised
- null
example: calm
description: 'Controls the emotional tone of the agent''s voice. Currently supported for Cartesia and Minimax TTS providers. If unset, no emotion will be used.
'
responsiveness:
type: number
minimum: 0
maximum: 1
example: 1
description: Controls how responsive is the agent. Value ranging from [0,1]. Lower value means less responsive agent (wait more, respond slower), while higher value means faster exchanges (respond when it can). If unset, default value 1 will apply.
interruption_sensitivity:
type: number
minimum: 0
maximum: 1
example: 1
description: Controls how sensitive the agent is to user interruptions. Value ranging from [0,1]. Lower value means it will take longer / more words for user to interrupt agent, while higher value means it's easier for user to interrupt agent. If unset, default value 1 will apply. When this is set to 0, agent would never be interrupted.
enable_backchannel:
type: boolean
example: true
description: Controls whether the agent would backchannel (agent interjects the speaker with phrases like "yeah", "uh-huh" to signify interest and engagement). Backchannel when enabled tends to show up more in longer user utterances. If not set, agent will not backchannel.
backchannel_frequency:
type: number
example: 0.9
description: Only applicable when enable_backchannel is true. Controls how often the agent would backchannel when a backchannel is possible. Value ranging from [0,1]. Lower value means less frequent backchannel, while higher value means more frequent backchannel. If unset, default value 0.8 will apply.
backchannel_words:
type: array
items:
type: string
example:
- yeah
- uh-huh
description: Only applicable when enable_backchannel is true. A list of words that the agent would use as backchannel. If not set, default backchannel words will apply. Check out [backchannel default words](/agent/interaction-configuration#backchannel) for more details. Note that certain voices do not work too well with certain words, so it's recommended to experiment before adding any words.
nullable: true
reminder_trigger_ms:
type: number
example: 10000
description: If set (in milliseconds), will trigger a reminder to the agent to speak if the user has been silent for the specified duration after some agent speech. Must be a positive number. If unset, default value of 10000 ms (10 s) will apply.
reminder_max_count:
type: integer
example: 2
description: If set, controls how many times agent would remind user when user is unresponsive. Must be a non negative integer. If unset, default value of 1 will apply (remind once). Set to 0 to disable agent from reminding.
ambient_sound:
type: string
enum:
- coffee-shop
- convention-hall
- summer-outdoor
- mountain-outdoor
- static-noise
- call-center
- null
description: 'If set, will add ambient environment sound to the call to make experience more realistic. Currently supports the following options:
- `coffee-shop`: Coffee shop ambience with people chatting in background. [Listen to Ambience](https://retell-utils-public.s3.us-west-2.amazonaws.com/coffee-shop.wav)
- `convention-hall`: Convention hall ambience, with some echo and people chatting in background. [Listen to Ambience](https://retell-utils-public.s3.us-west-2.amazonaws.com/convention-hall.wav)
- `summer-outdoor`: Summer outdoor ambience with cicada chirping. [Listen to Ambience](https://retell-utils-public.s3.us-west-2.amazonaws.com/summer-outdoor.wav)
- `mountain-outdoor`: Mountain outdoor ambience with birds singing. [Listen to Ambience](https://retell-utils-public.s3.us-west-2.amazonaws.com/mountain-outdoor.wav)
- `static-noise`: Constant static noise. [Listen to Ambience](https://retell-utils-public.s3.us-west-2.amazonaws.com/static-noise.wav)
- `call-center`: Call center work noise. [Listen to Ambience](https://retell-utils-public.s3.us-west-2.amazonaws.com/call-center.wav)
Set to `null` to remove ambient sound from this agent.
'
nullable: true
ambient_sound_volume:
type: number
example: 1
description: If set, will control the volume of the ambient sound. Value ranging from [0,2]. Lower value means quieter ambient sound, while higher value means louder ambient sound. If unset, default value 1 will apply.
language:
oneOf:
- $ref: '#/components/schemas/LanguageLegacy'
- type: array
items:
$ref: '#/components/schemas/Language'
description: Specifies what language(s) the agent will operate in. Accepts either a single scalar locale (e.g. `en-US`), the legacy scalar value `multi` for multilingual support, or an array of concrete locale codes for explicit multi-locale selection (e.g. `["en-US","es-ES"]`). The array form must contain concrete locale codes only — the `multi` value is valid only as the scalar legacy form and must not appear inside an array. Single-element arrays are normalized to the equivalent scalar on output. If unset, defaults to `en-US`.
webhook_url:
type: string
example: https://webhook-url-here
description: The webhook for agent to listen to call events. See what events it would get at [webhook doc](/features/webhook). If set, will binds webhook events for this agent to the specified url, and will ignore the account level webhook for this agent. Set to `null` to remove webhook url from this agent.
nullable: true
webhook_events:
type: array
items:
type: string
enum:
- call_started
- call_ended
- call_analyzed
- transcript_updated
- transfer_started
- transfer_bridged
- transfer_cancelled
- transfer_ended
description: Which webhook events this agent should receive. If not set, defaults to call_started, call_ended, call_analyzed.
nullable: true
webhook_timeout_ms:
type: integer
example: 10000
description: The timeout for the webhook in milliseconds. If not set, default value of 10000 will apply.
boosted_keywords:
type: array
items:
type: string
example:
- retell
- kroger
description: Provide a customized list of keywords to bias the transcriber model, so that these words are more likely to get transcribed. Commonly used for names, brands, street, etc.
nullable: true
data_storage_setting:
type: string
enum:
- everything
- everything_except_pii
- basic_attributes_only
example: everything
description: 'Granular setting to manage how Retell stores sensitive data (transcripts, recordings, logs, etc.).
This replaces the deprecated `opt_out_sensitive_data_storage` field.
- `everything`: Store all data including transcripts, recordings, and logs.
- `everything_except_pii`: Store data without PII when PII is detected.
- `basic_attributes_only`: Store only basic attributes; no transcripts/recordings/logs.
If not set, default value of "everything" will apply.
'
data_storage_retention_days:
type: integer
minimum: 1
maximum: 730
example: 30
nullable: true
description: Number of days to retain call/chat data before automatic deletion. Must be between 1 and 730 days. If not set, data is retained forever (no automatic deletion).
opt_in_signed_url:
type: boolean
example: true
description: Whether this agent opts in for signed URLs for public logs and recordings. When enabled, the generated URLs will include security signatures that restrict access and automatically expire after 24 hours.
signed_url_expiration_ms:
type: integer
example: 86400000
description: The expiration time for the signed url in milliseconds. Only applicable when opt_in_signed_url is true. If not set, default value of 86400000 (24 hours) will apply.
nullable: true
pronunciation_dictionary:
type: array
items:
type: object
required:
- word
- alphabet
- phoneme
properties:
word:
type: string
example: actually
description: The string of word / phrase to be annotated with pronunciation.
alphabet:
type: string
enum:
- ipa
- cmu
example: ipa
description: The phonetic alphabet to be used for pronunciation.
phoneme:
type: string
example: ˈæktʃuəli
description: Pronunciation of the word in the format of a IPA / CMU pronunciation.
description: A list of words / phrases and their pronunciation to be used to guide the audio synthesize for consistent pronunciation. Check the dashboard to see what provider supports this feature. Set to null to remove pronunciation dictionary from this agent.
nullable: true
end_call_after_silence_ms:
type: integer
example: 600000
description: If users stay silent for a period after agent speech, end the call. The minimum value allowed is 10,000 ms (10 s). By default, this is set to 600000 (10 min).
max_call_duration_ms:
type: integer
example: 3600000
description: Maximum allowed length for the call, will force end the call if reached. The minimum value allowed is 60,000 ms (1 min), and maximum value allowed is 7,200,000 (2 hours). By default, this is set to 3,600,000 (1 hour).
voicemail_message:
type: string
example: Hi, please give us a callback.
description: The message to be played when the call enters a voicemail. Note that this feature is only available for phone calls. If you want to hangup after hitting voicemail, set this to empty string.
voicemail_detection_timeout_ms:
type: integer
example: 30000
description: Configures when to stop running voicemail detection, as it becomes unlikely to hit voicemail after a couple minutes, and keep running it will only have negative impact. The minimum value allowed is 5,000 ms (5 s), and maximum value allowed is 180,000 (3 minutes). By default, this is set to 30,000 (30 s).
voicemail_option:
type: object
properties:
action:
$ref: '#/components/schemas/VoicemailAction'
detection_prompt:
type: string
maxLength: 2000
nullable: true
description: Optionally describe what should be treated as voicemail. Leave as null to use the default definition.
required:
- action
description: If this option is set, the call will try to detect voicemail in the first 3 minutes of the call. Actions defined (hangup, or leave a message) will be applied when the voicemail is detected. Set this to null to disable voicemail detection.
example:
action:
type: static_text
text: Please give us a callback tomorrow at 10am.
nullable: true
ivr_option:
type: object
properties:
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