Create Assistant

POST

Headers

Auth
AuthorizationstringRequired
Bearer authentication of the form Bearer <token>, where token is your auth token.

Request

This endpoint expects an object.
transcriberobjectOptional

These are the options for the assistant’s transcriber.

modelobjectOptional

These are the options for the assistant’s LLM.

voiceobjectOptional

These are the options for the assistant’s voice.

firstMessagestringOptional

This is the first message that the assistant will say. This can also be a URL to a containerized audio file (mp3, wav, etc.).

If unspecified, assistant will wait for user to speak and use the model to respond once they speak.

firstMessageModeenumOptional
Allowed values: assistant-speaks-firstassistant-speaks-first-with-model-generated-messageassistant-waits-for-user

This is the mode for the first message. Default is ‘assistant-speaks-first’.

Use:

  • ‘assistant-speaks-first’ to have the assistant speak first.
  • ‘assistant-waits-for-user’ to have the assistant wait for the user to speak first.
  • ‘assistant-speaks-first-with-model-generated-message’ to have the assistant speak first with a message generated by the model based on the conversation state. (assistant.model.messages at call start, call.messages at squad transfer points).

@default ‘assistant-speaks-first’

hipaaEnabledbooleanOptional

When this is enabled, no logs, recordings, or transcriptions will be stored. At the end of the call, you will still receive an end-of-call-report message to store on your server. Defaults to false.

clientMessageslist of enumsOptional

These are the messages that will be sent to your Client SDKs. Default is conversation-update,function-call,hang,model-output,speech-update,status-update,transfer-update,transcript,tool-calls,user-interrupted,voice-input. You can check the shape of the messages in ClientMessage schema.

serverMessageslist of enumsOptional

These are the messages that will be sent to your Server URL. Default is conversation-update,end-of-call-report,function-call,hang,speech-update,status-update,tool-calls,transfer-destination-request,user-interrupted. You can check the shape of the messages in ServerMessage schema.

silenceTimeoutSecondsdoubleOptional>=10<=3600

How many seconds of silence to wait before ending the call. Defaults to 30.

@default 30

maxDurationSecondsdoubleOptional>=10<=43200

This is the maximum number of seconds that the call will last. When the call reaches this duration, it will be ended.

@default 600 (10 minutes)

backgroundSound"off" or "office"Optional
Allowed values: offoffice

This is the background sound in the call. Default for phone calls is ‘office’ and default for web calls is ‘off’.

backgroundDenoisingEnabledbooleanOptional

This enables filtering of noise and background speech while the user is talking.

Default false while in beta.

@default false

modelOutputInMessagesEnabledbooleanOptional

This determines whether the model’s output is used in conversation history rather than the transcription of assistant’s speech.

Default false while in beta.

@default false

transportConfigurationslist of objectsOptional

These are the configurations to be passed to the transport providers of assistant’s calls, like Twilio. You can store multiple configurations for different transport providers. For a call, only the configuration matching the call transport provider is used.

namestringOptional<=40 characters

This is the name of the assistant.

This is required when you want to transfer between assistants in a call.

voicemailDetectionobjectOptional

These are the settings to configure or disable voicemail detection. Alternatively, voicemail detection can be configured using the model.tools=[VoicemailTool]. This uses Twilio’s built-in detection while the VoicemailTool relies on the model to detect if a voicemail was reached. You can use neither of them, one of them, or both of them. By default, Twilio built-in detection is enabled while VoicemailTool is not.

voicemailMessagestringOptional<=1000 characters

This is the message that the assistant will say if the call is forwarded to voicemail.

If unspecified, it will hang up.

endCallMessagestringOptional<=1000 characters

This is the message that the assistant will say if it ends the call.

If unspecified, it will hang up without saying anything.

endCallPhraseslist of stringsOptional

This list contains phrases that, if spoken by the assistant, will trigger the call to be hung up. Case insensitive.

metadatamap from strings to anyOptional

This is for metadata you want to store on the assistant.

analysisPlanobjectOptional

This is the plan for analysis of assistant’s calls. Stored in call.analysis.

artifactPlanobjectOptional

This is the plan for artifacts generated during assistant’s calls. Stored in call.artifact.

Note: recordingEnabled is currently at the root level. It will be moved to artifactPlan in the future, but will remain backwards compatible.

messagePlanobjectOptional

This is the plan for static predefined messages that can be spoken by the assistant during the call, like idleMessages.

Note: firstMessage, voicemailMessage, and endCallMessage are currently at the root level. They will be moved to messagePlan in the future, but will remain backwards compatible.

startSpeakingPlanobjectOptional

This is the plan for when the assistant should start talking.

You should configure this if you’re running into these issues:

  • The assistant is too slow to start talking after the customer is done speaking.
  • The assistant is too fast to start talking after the customer is done speaking.
  • The assistant is so fast that it’s actually interrupting the customer.
stopSpeakingPlanobjectOptional

This is the plan for when assistant should stop talking on customer interruption.

You should configure this if you’re running into these issues:

  • The assistant is too slow to recognize customer’s interruption.
  • The assistant is too fast to recognize customer’s interruption.
  • The assistant is getting interrupted by phrases that are just acknowledgments.
  • The assistant is getting interrupted by background noises.
  • The assistant is not properly stopping — it starts talking right after getting interrupted.
monitorPlanobjectOptional

This is the plan for real-time monitoring of the assistant’s calls.

Usage:

  • To enable live listening of the assistant’s calls, set monitorPlan.listenEnabled to true.
  • To enable live control of the assistant’s calls, set monitorPlan.controlEnabled to true.

Note, serverMessages, clientMessages, serverUrl and serverUrlSecret are currently at the root level but will be moved to monitorPlan in the future. Will remain backwards compatible

credentialIdslist of stringsOptional

These are the credentials that will be used for the assistant calls. By default, all the credentials are available for use in the call but you can provide a subset using this.

serverobjectOptional

This is where Vapi will send webhooks. You can find all webhooks available along with their shape in ServerMessage schema.

The order of precedence is:

  1. assistant.server.url
  2. phoneNumber.serverUrl
  3. org.serverUrl

Response

idstring

This is the unique identifier for the assistant.

orgIdstring

This is the unique identifier for the org that this assistant belongs to.

createdAtdatetime

This is the ISO 8601 date-time string of when the assistant was created.

updatedAtdatetime

This is the ISO 8601 date-time string of when the assistant was last updated.

transcriberobjectOptional

These are the options for the assistant’s transcriber.

modelobjectOptional

These are the options for the assistant’s LLM.

voiceobjectOptional

These are the options for the assistant’s voice.

firstMessagestringOptional

This is the first message that the assistant will say. This can also be a URL to a containerized audio file (mp3, wav, etc.).

If unspecified, assistant will wait for user to speak and use the model to respond once they speak.

firstMessageModeenumOptional
Allowed values: assistant-speaks-firstassistant-speaks-first-with-model-generated-messageassistant-waits-for-user

This is the mode for the first message. Default is ‘assistant-speaks-first’.

Use:

  • ‘assistant-speaks-first’ to have the assistant speak first.
  • ‘assistant-waits-for-user’ to have the assistant wait for the user to speak first.
  • ‘assistant-speaks-first-with-model-generated-message’ to have the assistant speak first with a message generated by the model based on the conversation state. (assistant.model.messages at call start, call.messages at squad transfer points).

@default ‘assistant-speaks-first’

hipaaEnabledbooleanOptional

When this is enabled, no logs, recordings, or transcriptions will be stored. At the end of the call, you will still receive an end-of-call-report message to store on your server. Defaults to false.

clientMessageslist of enumsOptional

These are the messages that will be sent to your Client SDKs. Default is conversation-update,function-call,hang,model-output,speech-update,status-update,transfer-update,transcript,tool-calls,user-interrupted,voice-input. You can check the shape of the messages in ClientMessage schema.

serverMessageslist of enumsOptional

These are the messages that will be sent to your Server URL. Default is conversation-update,end-of-call-report,function-call,hang,speech-update,status-update,tool-calls,transfer-destination-request,user-interrupted. You can check the shape of the messages in ServerMessage schema.

silenceTimeoutSecondsdoubleOptional>=10<=3600

How many seconds of silence to wait before ending the call. Defaults to 30.

@default 30

maxDurationSecondsdoubleOptional>=10<=43200

This is the maximum number of seconds that the call will last. When the call reaches this duration, it will be ended.

@default 600 (10 minutes)

backgroundSound"off" or "office"Optional
Allowed values: offoffice

This is the background sound in the call. Default for phone calls is ‘office’ and default for web calls is ‘off’.

backgroundDenoisingEnabledbooleanOptional

This enables filtering of noise and background speech while the user is talking.

Default false while in beta.

@default false

modelOutputInMessagesEnabledbooleanOptional

This determines whether the model’s output is used in conversation history rather than the transcription of assistant’s speech.

Default false while in beta.

@default false

transportConfigurationslist of objectsOptional

These are the configurations to be passed to the transport providers of assistant’s calls, like Twilio. You can store multiple configurations for different transport providers. For a call, only the configuration matching the call transport provider is used.

namestringOptional<=40 characters

This is the name of the assistant.

This is required when you want to transfer between assistants in a call.

voicemailDetectionobjectOptional

These are the settings to configure or disable voicemail detection. Alternatively, voicemail detection can be configured using the model.tools=[VoicemailTool]. This uses Twilio’s built-in detection while the VoicemailTool relies on the model to detect if a voicemail was reached. You can use neither of them, one of them, or both of them. By default, Twilio built-in detection is enabled while VoicemailTool is not.

voicemailMessagestringOptional<=1000 characters

This is the message that the assistant will say if the call is forwarded to voicemail.

If unspecified, it will hang up.

endCallMessagestringOptional<=1000 characters

This is the message that the assistant will say if it ends the call.

If unspecified, it will hang up without saying anything.

endCallPhraseslist of stringsOptional

This list contains phrases that, if spoken by the assistant, will trigger the call to be hung up. Case insensitive.

metadatamap from strings to anyOptional

This is for metadata you want to store on the assistant.

analysisPlanobjectOptional

This is the plan for analysis of assistant’s calls. Stored in call.analysis.

artifactPlanobjectOptional

This is the plan for artifacts generated during assistant’s calls. Stored in call.artifact.

Note: recordingEnabled is currently at the root level. It will be moved to artifactPlan in the future, but will remain backwards compatible.

messagePlanobjectOptional

This is the plan for static predefined messages that can be spoken by the assistant during the call, like idleMessages.

Note: firstMessage, voicemailMessage, and endCallMessage are currently at the root level. They will be moved to messagePlan in the future, but will remain backwards compatible.

startSpeakingPlanobjectOptional

This is the plan for when the assistant should start talking.

You should configure this if you’re running into these issues:

  • The assistant is too slow to start talking after the customer is done speaking.
  • The assistant is too fast to start talking after the customer is done speaking.
  • The assistant is so fast that it’s actually interrupting the customer.
stopSpeakingPlanobjectOptional

This is the plan for when assistant should stop talking on customer interruption.

You should configure this if you’re running into these issues:

  • The assistant is too slow to recognize customer’s interruption.
  • The assistant is too fast to recognize customer’s interruption.
  • The assistant is getting interrupted by phrases that are just acknowledgments.
  • The assistant is getting interrupted by background noises.
  • The assistant is not properly stopping — it starts talking right after getting interrupted.
monitorPlanobjectOptional

This is the plan for real-time monitoring of the assistant’s calls.

Usage:

  • To enable live listening of the assistant’s calls, set monitorPlan.listenEnabled to true.
  • To enable live control of the assistant’s calls, set monitorPlan.controlEnabled to true.

Note, serverMessages, clientMessages, serverUrl and serverUrlSecret are currently at the root level but will be moved to monitorPlan in the future. Will remain backwards compatible

credentialIdslist of stringsOptional

These are the credentials that will be used for the assistant calls. By default, all the credentials are available for use in the call but you can provide a subset using this.

serverobjectOptional

This is where Vapi will send webhooks. You can find all webhooks available along with their shape in ServerMessage schema.

The order of precedence is:

  1. assistant.server.url
  2. phoneNumber.serverUrl
  3. org.serverUrl
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