Guide

Webhooks

When an assistant has a webhook_url, Revox sends an HTTP POST with a JSON body to that URL after its calls. Set it with POST /assistants or PATCH /assistants/{id}.

Answer with a 2xx status quickly, then do the work asynchronously.
Requests are not signed. To make sure a request comes from Revox, put a secret token in the URL (https://example.com/revox-webhook?token=...) and check it, or fetch the call again with GET /call/{id} before acting on it.
The call in the payload is the same object GET /call/{id} returns.

Payload

Webhook called when a call is completed.

callCallrequired
call_attemptCallAttemptrequired
assistantobjectrequirednullable
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- idstringrequired
- typeenum (string)required
  One ofstandalonemulti-stepsub-assistant
- positionobjectrequirednullable
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  xnumberrequired
  ynumberrequired
- start_step_namestringrequirednullable
- promptstringrequired
- post_call_promptstringrequirednullable
- first_sentencestringrequirednullable
- first_sentence_modeenum (string)required
  One ofgeneratedstaticnone
- end_of_call_sentencestringrequirednullable
- voiceobjectrequirednullable
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  providerenum (string)required
  The provider of the voice.
  One ofcartesiaelevenlabsgradium
  idstringrequired
  The ID of the voice.
  min length 1
  speednumber
  The speed of the voice. Range depends on provider: Cartesia 0.6–1.5, ElevenLabs 0.7–1.2, Gradium 0.6–1.5. Default is 1.0.
  min 0.6 · max 1.5
  volumenumber
  Volume of the voice (Cartesia only). 0.5–2.0, default 1.0. Ignored for other providers.
  min 0.5 · max 2
  modelenum (string)
  Cartesia TTS model (Cartesia only). Defaults to sonic-3.6 when omitted. Ignored for other providers.
  One ofsonic-3sonic-3.5sonic-3.6
- voice_languagesarray of objectrequirednullable
  Extra languages for a multilingual assistant, each with its own voice. Null for a single-language assistant.
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  languageenum (string)required
  The language contacts are called in with this voice.
  One ofenfresdeitptruzh
  voiceobjectrequired
  The voice used for contacts whose language is this language.
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  providerenum (string)required
  The provider of the voice.
  One ofcartesiaelevenlabsgradium
  idstringrequired
  The ID of the voice.
  min length 1
  speednumber
  The speed of the voice. Range depends on provider: Cartesia 0.6–1.5, ElevenLabs 0.7–1.2, Gradium 0.6–1.5. Default is 1.0.
  min 0.6 · max 1.5
  volumenumber
  Volume of the voice (Cartesia only). 0.5–2.0, default 1.0. Ignored for other providers.
  min 0.5 · max 2
  modelenum (string)
  Cartesia TTS model (Cartesia only). Defaults to sonic-3.6 when omitted. Ignored for other providers.
  One ofsonic-3sonic-3.5sonic-3.6
- cartesia_dictionary_pronunciation_idstringrequirednullable
  Optional Cartesia pronunciation dictionary ID linked to this assistant.
- llm_modelone ofrequired
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  One ofRecommendedobject
  typestring (constant)required
  The LLM Revox currently recommends for voice agents, chosen server-side and upgraded without any change on your side. No per-assistant configuration.
  Always "recommended"
  One ofGpt41Priorityobject
  typestring (constant)required
  OpenAI gpt-4.1 on the priority tier, with gpt-4.1-mini answering a turn when gpt-4.1 is slow to respond. No per-assistant configuration.
  Always "gpt-4.1-priority"
  One ofRealtimeobject
  typestring (constant)required
  Use a model from Realtime.
  Always "realtime"
  providerenum (string)required
  The provider to use from Realtime. eg: openai, google.
  One ofopenaigoogle
  realtime_model_idstringrequired
  The model ID to use from Realtime. eg: gpt-4.1
  realtime_voice_idstring
  Output voice for the realtime provider (e.g. OpenAI: marin; Gemini: Puck).
  min length 1
- webhook_urlstringrequirednullable
  The webhook URL to call when the call is completed.
- max_call_duration_secsnumberrequired
  The maximum duration of the call in seconds. This is the maximum time the call will be allowed to run.
- max_duration_end_messagestringrequirednullable
  Optional message the agent will say, without being interruptible, when the call reaches its max duration. Kept short so it fits inside the farewell buffer. If null, the call ends silently.
  max length 150
- structured_output_configarray of StructuredOutputFieldrequirednullable
  The structured output config to use for the call. This is used to extract the data from the call (like email, name, company name, etc.).
- structured_output_promptstringrequirednullable
  Custom prompt for structured data extraction. If not provided, a default prompt is used. Available variables: {{transcript}}, {{call_direction}}, {{user_phone_number}}, {{agent_phone_number}}.
- call_retry_configCallRetryConfigrequirednullable
  Configuration for call retry behavior including time windows, delays, and max iterations.
- background_soundenum (string)requirednullable
  Ambient background sound to play during the call. null disables it.
  One ofaudio/office.oggaudio/waves.m4a
- background_sound_volumenumberrequired
  Volume of the ambient background sound (0 = silent, 1 = max).
  min 0 · max 1
- thinking_soundenum (string)requirednullable
  Audio clip to play while the agent is processing a response. One of the built-in LiveKit audio clips; null disables it.
  One ofcity-ambience.oggforest-ambience.oggoffice-ambience.oggcrowded-room.oggkeyboard-typing.oggkeyboard-typing2.ogghold_music.ogg
- thinking_sound_volumenumberrequired
  Volume of the thinking sound (0 = silent, 1 = max).
  min 0 · max 1
- thinking_sound_probabilitynumberrequired
  Probability [0..1] that the thinking sound plays on any given turn; otherwise the agent is silent while thinking.
  min 0 · max 1
- transfer_destinationsarray of objectrequirednullable
  Where calls can be transferred to when users ask to speak to a human. Null or empty when transfer is not configured.
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  labelstringrequired
  min length 1 · max length 60
  phone_numberstringrequired
- human_transfer_modeenum (string)requirednullable
  Warm or cold transfer when transfer_destinations is non-empty; null when transfer is not configured.
  One ofwarmcold
- warm_transfer_summary_instructionsstringrequirednullable
  Warm transfer only: instructions for the supervisor handoff summary; null when not configured or cold transfer.
- warm_transfer_voice_speednumberrequirednullable
  Warm transfer only: voice speed of the briefing to the human colleague; null when it follows voice.speed, not configured, or cold transfer.
  min 0.6 · max 1.5
- ivr_navigation_enabledbooleanrequired
  Enable IVR navigation tools. When enabled, the assistant can send DTMF tones and skip turns to navigate phone menus.
- voicemail_messagestringrequirednullable
  If set, when voicemail is detected the agent will speak this message then hang up; if null, hang up immediately.
- stt_contextobjectrequirednullable
  Assistant-level speech-to-text context: structured general key/value pairs plus a list of domain terms. Prompt-derived context is merged in without replacing existing entries.
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  generalarray of objectrequired
  Default []
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  keystringrequired
  min length 1
  valuestringrequired
  min length 1
  termsarray of stringrequired
  Default []
- stt_modelenum (string)required
  Transcriber (speech-to-text) model used for the assistant.
  One ofstt-rt-v4stt-rt-v5
- stt_endpoint_sensitivitynumberrequirednullable
  Soniox endpoint sensitivity override (-1 to 1). Null: the agent's default tuning.
- stt_endpoint_latency_levelintegerrequirednullable
  Soniox endpoint latency adjustment level override (0 to 3). Null: the agent's default tuning.
  min -9007199254740991 · max 9007199254740991
- stt_bvc_filter_enabledbooleanrequired
  When false, the agent transcribes the raw caller track instead of the BVC noise-cancellation output.
- krisp_viva_filter_enabledbooleanrequired
  When true, the agent's noise-cancellation filter is Krisp VIVA Tel instead of the legacy BVCTelephony.
- first_sentence_delay_msintegerrequired
  Delay in milliseconds before speaking the first sentence. Default: 400.
  min -9007199254740991 · max 9007199254740991
- calendarsarray of AssistantCalendarrequired
  The calendars the agent books meetings on during a call, each named by the handle the prompt mentions. Only the ready ones are offered to the agent.
- calendlyobjectrequirednullable
  Deprecated: an assistant now books on any number of calendars, managed with the assistant calendars endpoints and listed in calendars. This field stands for the assistant's first ready calendar of this provider: setting it creates or updates that calendar, null removes it. The dashboard ignores it.
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  connection_idstringrequired
  The connection ID representing the link between your Calendly account and Revox.
  event_type_idstringrequired
  The Calendly event type to schedule. (eg: https://api.calendly.com/event_types/b2330295-2a91-4a1d-bb73-99e7707663d5)
  min length 1
- calobjectrequirednullable
  Deprecated: an assistant now books on any number of calendars, managed with the assistant calendars endpoints and listed in calendars. This field stands for the assistant's first ready calendar of this provider: setting it creates or updates that calendar, null removes it. The dashboard ignores it.
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  connection_idstringrequired
  The connection ID representing the link between your Cal.com account and Revox.
  event_type_idstringrequired
  The Cal.com event type to schedule. (eg: 7081322)
  min length 1
- google_calendarobjectrequirednullable
  Deprecated: an assistant now books on any number of calendars, managed with the assistant calendars endpoints and listed in calendars. This field stands for the assistant's first ready calendar of this provider: setting it creates or updates that calendar, null removes it. The dashboard ignores it.
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  calendar_idstringrequired
  The Google calendar to book on. (eg: primary)
  time_zonestringrequired
  The timezone of the opening hours. (eg: Europe/Paris)
  duration_minutesintegerrequired
  min 5 · max 480Default 30
  daysarray of integerrequired
  The open days, 0 is Sunday.
  Default [1,2,3,4,5]
  start_timestringrequired
  pattern ^\d{2}:\d{2}$Default "09:00"
  end_timestringrequired
  pattern ^\d{2}:\d{2}$Default "18:00"
  google_meetbooleanrequired
  Adds a Google Meet link to the meeting.
  Default true
  connection_idstringrequired
  The connection ID representing the link between your Google account and Revox.
- hubspotobjectrequirednullable
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  connection_idstringrequired
  The Nango connection ID linking the org's HubSpot account to Revox.
  precall_lookup_enabledbooleanrequired
  Resolve the caller against HubSpot contacts before answering an inbound call, filling the contact_* prompt variables (contact_name, contact_owner, contact_lead_status, contact_has_open_deal). Off by default: it costs API calls before the phone is picked up.
  Default false
  meeting_linksarray of objectrequired
  Scheduling pages the agent can book on during a call — typically one per sales rep plus a round-robin team page marked as the fallback.
  Default []
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  slugstringrequired
  HubSpot scheduling page slug, as returned by the meeting-links API (e.g. 'julien-marchand').
  min length 1
  labelstringrequired
  Name the agent recognises for this calendar (e.g. 'Julien Marchand'). Listed in the prompt and matched against what the caller asks for.
  min length 1
  duration_msintegerrequired
  Meeting duration in milliseconds, chosen among the durations the scheduling page offers (e.g. 1800000 for 30 minutes).
  max 9007199254740991 · > 0
  is_fallbackbooleanrequired
  Marks the round-robin calendar the agent falls back to when the requested rep has no slot. At most one meeting link may set this.
  booking_urlstringrequirednullable
  Public URL of the scheduling page (e.g. https://meetings-eu1.hubspot.com/julien). The agent books through the API and only texts this link to the caller when the booking fails and the call can receive an SMS. Null on calendars saved before this field existed.
  Default null
  post_call_syncobject
  Sends call data back to HubSpot after the call. Off until set: connecting HubSpot to book meetings must not start writing to the CRM. Always present in responses; omit it on update to leave the current setting untouched.
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  enabledbooleanrequired
  Records calls in HubSpot after they end: the contact is created or updated from the phone number and the call is logged on its timeline. By default every call a person answered is recorded. When the post-call prompt talks about the CRM (in plain words or by mentioning the crm_push_call tool), the post-call agent decides instead which calls are recorded and what the logged call says.
  Default false
  field_mappingarray of objectrequired
  Maps extracted call fields (structured_output / prompt variables) onto HubSpot contact properties.
  Default []
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  sourcestringrequired
  Source key to read from the call: a structured_output field name, falling back to a prompt variable of the same name.
  min length 1
  hubspot_propertystringrequired
  Destination HubSpot contact property, by internal name (e.g. 'email', 'company', or a custom 'budget').
  min length 1
- slackobjectrequirednullable
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  connection_idstringrequired
  The Nango connection ID linking the org's Slack workspace to Revox.
  channelsarray of objectrequired
  The Slack channels the post-call agent may post to. It resolves the channel it was told to use against this list and cannot reach any other.
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  idstringrequired
  The Slack channel ID (e.g. 'C01234567').
  namestringnullable
  Human-readable Slack channel name, cached for display in the UI and given to the LLM when the agent prompt routes by channel name.
- teamsobjectrequirednullable
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  connection_idstringrequired
  The Nango connection ID linking a Microsoft Teams account to Revox. Messages are posted as that account.
  channelsarray of objectrequired
  The Teams channels the post-call agent may post to. It resolves the channel it was told to use against this list and cannot reach any other.
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  idstringrequired
  The Microsoft Teams channel ID (e.g. '19:561fbdbb...@thread.tacv2').
  namestringnullable
  Human-readable channel name, cached for display in the UI and given to the LLM when the agent prompt routes by channel name.
  team_idstringrequired
  The ID of the team the channel belongs to. Needed to post.
  team_namestringnullable
  Human-readable team name. Channel names repeat across teams (every team has a 'General'), so the team name is what tells two of them apart.
- zohoobjectrequirednullable
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  connection_idstringrequired
  The Nango connection ID linking the org's Zoho CRM account to Revox.
  modulestringrequired
  Zoho module the prospect record is upserted into (e.g. 'Leads' or 'Contacts').
  min length 1
  log_call_activitybooleanrequired
  When true, also log the call as a record in Zoho's Calls module (related to the upserted prospect via Who_Id).
  field_mappingarray of objectrequired
  Maps extracted call fields (structured_output / prompt variables) onto Zoho field API names on the upserted record.
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  sourcestringrequired
  Source key to read from the call: a structured_output field name, falling back to a prompt variable of the same name.
  min length 1
  zoho_fieldstringrequired
  Destination Zoho field API name on the upserted record (e.g. 'Email', 'Company', or a custom 'Budget__c').
  min length 1
  templatestringnullable
  Optional Note body template. Supports {{summary}}, {{outcome}}, {{phone}}, {{call_url}}, {{assistant_name}}, {{campaign_name}}, {{transcript}}, plus prompt_variables and structured_output keys. When null/empty a default note (outcome + summary + auto-listed extracted fields) is used.
- custom_toolsarray of objectrequirednullable
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  namestringrequired
  Unique tool name in lowercase_snake_case (e.g. check_inventory)
  min length 1 · pattern ^[a-z][a-z0-9_]*$
  descriptionstringrequired
  Human-readable description of what the tool does, used by the LLM to decide when to call it
  min length 1
  methodenum (string)required
  HTTP method to use when calling the API endpoint
  One ofGETPOSTPUTPATCHDELETE
  urlstringrequired
  Full URL of the API endpoint. Supports {{variable}} placeholders for dynamic values
  min length 1
  headersarray of objectrequired
  HTTP headers to include in the request. Values support {{variable}} placeholders
  Default []
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  keystringrequired
  min length 1
  valuestringrequired
  query_paramsarray of objectrequired
  Query string parameters appended to the URL. Values support {{variable}} placeholders
  Default []
  Show 2 fieldsHide 2 fields
  keystringrequired
  min length 1
  valuestringrequired
  body_templatestringrequirednullable
  JSON body template for the request. Use quoted {{variable}} placeholders (e.g. "{{name}}") for dynamic values
  Default null
  input_schemaarray of StructuredOutputFieldrequired
  Schema defining the parameters the LLM should extract from the conversation to pass to this tool
- from_phone_numberstringrequirednullable
  Override the default outbound phone number for calls placed with this assistant. When null, the organization's default phone number is used.
- logo_urlstringrequirednullable
  Public URL of the brand logo shown on the assistant's demo page. Null when unset.
- precall_lookup_urlstringrequirednullable
  URL fetched before an inbound call is answered to resolve the assistant's prompt variables. Null when no lookup is configured.
- precall_lookup_headersarray of objectrequirednullable
  HTTP headers sent with the pre-call lookup request. Null when none are configured.
  Show 2 fieldsHide 2 fields
  keystringrequired
  max length 200 · pattern ^[A-Za-z0-9!#$%&'*+.^_`|~-]+$
  valuestringrequired
  min length 1 · max length 4000