From d693d468d8a3f0f9ff53f1c6df2bd28811600d51 Mon Sep 17 00:00:00 2001
From: Tanmay Deep Sharma <tanmaydeepsharma21@gmail.com>
Date: Mon, 4 May 2026 15:38:28 +0700
Subject: [PATCH] feat(voice): bridge WhatsApp Cloud Calling to Chatwoot voice
 pipeline
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Wires Meta's WhatsApp Cloud Calling APIs into the voice subsystem so
agents can answer / place calls on WhatsApp Cloud inboxes from the
existing Voice flow. Browser ↔ Meta WebRTC is direct (no media-server
hop); Chatwoot owns the signalling, recording upload, and lifecycle
state on the Call/Message records.

Backend
- API surface: new Api::V1::Accounts::WhatsappCallsController with
  show / accept / reject / terminate / initiate / upload_recording.
  Enforces conversation-level Pundit visibility, blocks initiate when
  the channel isn't embedded-signup voice-enabled, and surfaces the
  Meta 138006 (no-call-permission) flow as a throttled opt-in template
  send under a conversation lock so concurrent retries can't double-send.
- Whatsapp::CallService — accept/reject/terminate state machine with
  call-level locking; wraps Meta API failures (transport or business)
  as Voice::CallErrors::CallFailed so the controller renders 422.
- Whatsapp::IncomingCallService — handles Meta connect/terminate
  webhooks; pins setup:active on outbound answers, materialises a
  missed-call record when terminate arrives before connect, and
  broadcasts voice_call.* events to assignee or account streams.
- Whatsapp::Providers::WhatsappCloudService — adds pre_accept/accept/
  reject/terminate/initiate/permission-request endpoints. Uses
  configurable WHATSAPP_API_VERSION (default v22) since the Calls API
  needs v17+ and OSS phone_id_path is locked at v13.
- Audio recordings: Attachment after_create_commit enqueues
  transcription and rebroadcasts the message so the FE bubble updates
  immediately. Active Storage initializer allows audio MIME types to
  serve inline. Audio transcription drops Whisper temperature to 0 to
  suppress hallucinations on silence.
- Channel::Voice stub backs legacy inbox rows whose channel_type
  survived the DropChannelVoice migration so jbuilder .try chains
  short-circuit instead of raising.

Routes / config
- /api/v1/accounts/:id/whatsapp_calls/* (enterprise-only)
- en.yml error strings under errors.whatsapp.calls.*

The FE consumer of this API ships separately on feat/whatsapp-call-ui.
---
 app/models/attachment.rb                      |  12 ++
 app/models/channel/whatsapp.rb                |   6 +-
 app/services/base/send_on_channel_service.rb  |   3 +-
 app/views/api/v1/models/_inbox.json.jbuilder  |   3 +
 config/initializers/active_storage.rb         |  13 ++
 config/locales/en.yml                         |   7 +
 config/routes.rb                              |  15 ++
 .../v1/accounts/whatsapp_calls_controller.rb  | 162 ++++++++++++++++++
 enterprise/app/models/call.rb                 |   2 -
 enterprise/app/models/channel/voice.rb        |   8 +
 .../models/enterprise/concerns/attachment.rb  |  17 ++
 .../app/models/enterprise/conversation.rb     |  15 ++
 .../providers/whatsapp_cloud_service.rb       |  17 +-
 .../messages/audio_transcription_service.rb   |   4 +-
 .../app/services/whatsapp/call_service.rb     | 102 +++++++++++
 .../whatsapp/incoming_call_service.rb         |  17 +-
 .../whatsapp_calls/accept.json.jbuilder       |   1 +
 .../whatsapp_calls/initiate.json.jbuilder     |   5 +
 .../whatsapp_calls/reject.json.jbuilder       |   2 +
 .../whatsapp_calls/show.json.jbuilder         |   1 +
 .../whatsapp_calls/terminate.json.jbuilder    |   2 +
 .../upload_recording.json.jbuilder            |   2 +
 .../v1/models/_whatsapp_call.json.jbuilder    |  24 +++
 23 files changed, 431 insertions(+), 9 deletions(-)
 create mode 100644 config/initializers/active_storage.rb
 create mode 100644 enterprise/app/controllers/api/v1/accounts/whatsapp_calls_controller.rb
 create mode 100644 enterprise/app/models/channel/voice.rb
 create mode 100644 enterprise/app/services/whatsapp/call_service.rb
 create mode 100644 enterprise/app/views/api/v1/accounts/whatsapp_calls/accept.json.jbuilder
 create mode 100644 enterprise/app/views/api/v1/accounts/whatsapp_calls/initiate.json.jbuilder
 create mode 100644 enterprise/app/views/api/v1/accounts/whatsapp_calls/reject.json.jbuilder
 create mode 100644 enterprise/app/views/api/v1/accounts/whatsapp_calls/show.json.jbuilder
 create mode 100644 enterprise/app/views/api/v1/accounts/whatsapp_calls/terminate.json.jbuilder
 create mode 100644 enterprise/app/views/api/v1/accounts/whatsapp_calls/upload_recording.json.jbuilder
 create mode 100644 enterprise/app/views/api/v1/models/_whatsapp_call.json.jbuilder

diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 769e134be..8c87ff433 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -104,11 +104,23 @@ class Attachment < ApplicationRecord
     audio_file_data = base_data.merge(file_metadata)
     audio_file_data.merge(
       {
+        # ActiveStorage's redirect endpoint defaults to Content-Disposition: attachment,
+        # which makes <audio> elements download instead of play. Force inline so the
+        # call-recording chip (and any other audio bubble) can stream directly.
+        data_url: inline_audio_url,
         transcribed_text: meta&.[]('transcribed_text') || ''
       }
     )
   end
 
+  def inline_audio_url
+    return '' unless file.attached?
+
+    # Proxy endpoint streams through Rails and honours `disposition: 'inline'`,
+    # unlike the redirect endpoint which always sends Content-Disposition: attachment.
+    Rails.application.routes.url_helpers.rails_storage_proxy_url(file, disposition: 'inline')
+  end
+
   def file_metadata
     metadata = {
       extension: extension,
diff --git a/app/models/channel/whatsapp.rb b/app/models/channel/whatsapp.rb
index 656486006..12b18c90b 100644
--- a/app/models/channel/whatsapp.rb
+++ b/app/models/channel/whatsapp.rb
@@ -41,8 +41,12 @@ class Channel::Whatsapp < ApplicationRecord
   end
 
   # Mirrors Channel::TwilioSms#voice_enabled? so the call subsystem can duck-type across providers.
+  # Meta's Calling API is only available via the embedded-signup whatsapp_cloud flow —
+  # 360dialog (default provider) and manual whatsapp_cloud setups can't reach the call APIs.
   def voice_enabled?
-    provider_config['calling_enabled'].present?
+    provider == 'whatsapp_cloud' &&
+      provider_config['source'] == 'embedded_signup' &&
+      provider_config['calling_enabled'].present?
   end
 
   def provider_service
diff --git a/app/services/base/send_on_channel_service.rb b/app/services/base/send_on_channel_service.rb
index 298f60962..44380a179 100644
--- a/app/services/base/send_on_channel_service.rb
+++ b/app/services/base/send_on_channel_service.rb
@@ -46,7 +46,8 @@ class Base::SendOnChannelService
   def invalid_message?
     # private notes aren't send to the channels
     # we should also avoid the case of message loops, when outgoing messages are created from channel
-    message.private? || outgoing_message_originated_from_channel?
+    # voice_call bubbles are call status indicators, not deliverable messages
+    message.private? || outgoing_message_originated_from_channel? || message.content_type == 'voice_call'
   end
 
   def validate_target_channel
diff --git a/app/views/api/v1/models/_inbox.json.jbuilder b/app/views/api/v1/models/_inbox.json.jbuilder
index e4c19fea0..89a6258ad 100644
--- a/app/views/api/v1/models/_inbox.json.jbuilder
+++ b/app/views/api/v1/models/_inbox.json.jbuilder
@@ -142,3 +142,6 @@ if resource.twilio? && resource.channel.respond_to?(:voice_enabled?)
     json.voice_status_webhook_url resource.channel.try(:voice_status_webhook_url)
   end
 end
+
+## Voice attribute for WhatsApp Cloud (only embedded-signup channels surface true)
+json.voice_enabled resource.channel.voice_enabled? if resource.channel_type == 'Channel::Whatsapp' && resource.channel.respond_to?(:voice_enabled?)
diff --git a/config/initializers/active_storage.rb b/config/initializers/active_storage.rb
new file mode 100644
index 000000000..d927e1472
--- /dev/null
+++ b/config/initializers/active_storage.rb
@@ -0,0 +1,13 @@
+# Allow audio attachments (call recordings, voice notes) to serve inline so the
+# in-app <audio> player can stream them. Without this, ActiveStorage's blob model
+# forces Content-Disposition: attachment for any MIME outside the default allowlist
+# (images + PDF), which makes the browser download instead of play.
+Rails.application.config.active_storage.content_types_allowed_inline += %w[
+  audio/webm
+  audio/ogg
+  audio/mpeg
+  audio/mp4
+  audio/x-m4a
+  audio/wav
+  audio/x-wav
+]
diff --git a/config/locales/en.yml b/config/locales/en.yml
index c225392a4..ca77e45a7 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -114,6 +114,13 @@ en:
       reauthorization:
         generic: 'Failed to reauthorize WhatsApp. Please try again.'
         not_supported: 'Reauthorization is not supported for this type of WhatsApp channel.'
+      calls:
+        not_enabled: 'Calling is not enabled for this inbox'
+        no_recording: 'No recording file provided'
+        no_message: 'Call has no associated message'
+        sdp_offer_required: 'sdp_offer is required'
+        contact_phone_required: 'Contact phone number is required'
+        permission_request_failed: 'Failed to send call permission request'
     inboxes:
       imap:
         socket_error: Please check the network connection, IMAP address and try again.
diff --git a/config/routes.rb b/config/routes.rb
index eff17e714..ebb38efc4 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -215,6 +215,21 @@ Rails.application.routes.draw do
             end
           end
           resources :reporting_events, only: [:index] if ChatwootApp.enterprise?
+
+          if ChatwootApp.enterprise?
+            resources :whatsapp_calls, only: [:show] do
+              member do
+                post :accept
+                post :reject
+                post :terminate
+                post :upload_recording
+              end
+              collection do
+                post :initiate
+              end
+            end
+          end
+
           resources :custom_attribute_definitions, only: [:index, :show, :create, :update, :destroy]
           resources :custom_filters, only: [:index, :show, :create, :update, :destroy]
           resources :inboxes, only: [:index, :show, :create, :update, :destroy] do
diff --git a/enterprise/app/controllers/api/v1/accounts/whatsapp_calls_controller.rb b/enterprise/app/controllers/api/v1/accounts/whatsapp_calls_controller.rb
new file mode 100644
index 000000000..c1dbacecd
--- /dev/null
+++ b/enterprise/app/controllers/api/v1/accounts/whatsapp_calls_controller.rb
@@ -0,0 +1,162 @@
+class Api::V1::Accounts::WhatsappCallsController < Api::V1::Accounts::BaseController
+  PERMISSION_REQUEST_THROTTLE = 5.minutes
+
+  before_action :set_call, only: %i[show accept reject terminate upload_recording]
+  before_action :set_conversation, only: :initiate
+  before_action :ensure_calling_enabled, only: :initiate
+  before_action :ensure_sdp_offer, only: :initiate
+  before_action :ensure_contact_phone, only: :initiate
+  before_action :ensure_recording_present, only: :upload_recording
+  before_action :ensure_call_message, only: :upload_recording
+
+  rescue_from Voice::CallErrors::NotRinging,
+              Voice::CallErrors::AlreadyAccepted,
+              Voice::CallErrors::CallFailed,
+              with: :render_call_error
+  rescue_from Voice::CallErrors::NoCallPermission, with: :render_permission_request
+
+  def show; end
+
+  def accept
+    call_service.accept
+  end
+
+  def reject
+    call_service.reject
+  end
+
+  def terminate
+    call_service.terminate
+  end
+
+  def upload_recording
+    @upload_status = @call.message.with_lock { attach_recording_idempotently }
+  end
+
+  def initiate
+    @call = create_outbound_call
+    @message = Voice::CallMessageBuilder.new(@call).perform!
+    @call.update!(message_id: @message.id)
+  end
+
+  private
+
+  def call_service
+    @call_service ||= Whatsapp::CallService.new(call: @call, agent: Current.user, sdp_answer: params[:sdp_answer])
+  end
+
+  def provider_service
+    @provider_service ||= @conversation.inbox.channel.provider_service
+  end
+
+  def set_call
+    @call = Current.account.calls.whatsapp.find(params[:id])
+    authorize @call.conversation, :show?
+  end
+
+  def set_conversation
+    @conversation = Current.account.conversations.find_by!(display_id: params[:conversation_id])
+    authorize @conversation, :show?
+  end
+
+  def ensure_calling_enabled
+    channel = @conversation.inbox.channel
+    return if channel.is_a?(Channel::Whatsapp) && channel.voice_enabled?
+
+    render_could_not_create_error(I18n.t('errors.whatsapp.calls.not_enabled'))
+  end
+
+  def ensure_sdp_offer
+    return if params[:sdp_offer].present?
+
+    render_could_not_create_error(I18n.t('errors.whatsapp.calls.sdp_offer_required'))
+  end
+
+  def ensure_contact_phone
+    return if @conversation.contact&.phone_number.present?
+
+    render_could_not_create_error(I18n.t('errors.whatsapp.calls.contact_phone_required'))
+  end
+
+  def ensure_recording_present
+    return if params[:recording].present?
+
+    render_could_not_create_error(I18n.t('errors.whatsapp.calls.no_recording'))
+  end
+
+  def ensure_call_message
+    return if @call.message.present?
+
+    render_could_not_create_error(I18n.t('errors.whatsapp.calls.no_message'))
+  end
+
+  def attach_recording_idempotently
+    return 'already_uploaded' if @call.message.attachments.exists?(file_type: :audio)
+
+    @call.message.attachments.create!(account_id: @call.account_id, file_type: :audio, file: params[:recording])
+    'uploaded'
+  end
+
+  def create_outbound_call
+    contact_phone = @conversation.contact.phone_number.delete('+')
+    result = provider_service.initiate_call(contact_phone, params[:sdp_offer])
+    provider_call_id = result.dig('calls', 0, 'id') || result['call_id']
+
+    Current.account.calls.create!(
+      provider: :whatsapp, inbox: @conversation.inbox, conversation: @conversation, contact: @conversation.contact,
+      provider_call_id: provider_call_id, direction: :outgoing, status: 'ringing',
+      accepted_by_agent_id: Current.user.id,
+      meta: { 'sdp_offer' => params[:sdp_offer], 'ice_servers' => Call.default_ice_servers }
+    )
+  end
+
+  # Meta error 138006 means the contact hasn't opted in yet; send the opt-in
+  # template (throttled, behind a conversation lock to prevent double-send).
+  def render_permission_request
+    status = nil
+    @conversation.with_lock do
+      if permission_request_throttled?
+        status = 'permission_pending'
+        next
+      end
+
+      sent = send_permission_request_safely
+      if sent
+        record_permission_request_wamid(sent)
+        status = 'permission_requested'
+      else
+        status = 'failed'
+      end
+    end
+
+    return render_could_not_create_error(I18n.t('errors.whatsapp.calls.permission_request_failed')) if status == 'failed'
+
+    render json: { status: status }
+  end
+
+  def permission_request_throttled?
+    last_requested = @conversation.additional_attributes&.dig('call_permission_requested_at')
+    last_requested.present? && Time.zone.parse(last_requested) > PERMISSION_REQUEST_THROTTLE.ago
+  end
+
+  # Treat transport errors as a falsy return so we render 422 rather than 500.
+  def send_permission_request_safely
+    provider_service.send_call_permission_request(@conversation.contact.phone_number.delete('+'))
+  rescue StandardError => e
+    Rails.logger.warn "[WHATSAPP CALL] permission_request failed: #{e.class} #{e.message}"
+    nil
+  end
+
+  # Stash the outbound wamid so the reply webhook can match context.id back here.
+  def record_permission_request_wamid(sent)
+    attrs = (@conversation.additional_attributes || {}).merge(
+      'call_permission_requested_at' => Time.current.iso8601,
+      'call_permission_request_message_id' => sent.dig('messages', 0, 'id')
+    )
+    @conversation.update!(additional_attributes: attrs)
+  end
+
+  def render_call_error(error)
+    render_could_not_create_error(error.message)
+  end
+end
diff --git a/enterprise/app/models/call.rb b/enterprise/app/models/call.rb
index 51c7ef5e9..26b81fe3c 100644
--- a/enterprise/app/models/call.rb
+++ b/enterprise/app/models/call.rb
@@ -29,9 +29,7 @@
 #  index_calls_on_provider_and_provider_call_id   (provider,provider_call_id) UNIQUE
 #
 class Call < ApplicationRecord
-  # All valid call statuses
   STATUSES = %w[ringing in_progress completed no_answer failed].freeze
-  # Statuses where the call is finished and won't change again
   TERMINAL_STATUSES = %w[completed no_answer failed].freeze
 
   store_accessor :meta, :conference_sid, :recording_sid, :parent_call_sid, :initiated_at, :ended_at
diff --git a/enterprise/app/models/channel/voice.rb b/enterprise/app/models/channel/voice.rb
new file mode 100644
index 000000000..c98816df4
--- /dev/null
+++ b/enterprise/app/models/channel/voice.rb
@@ -0,0 +1,8 @@
+# Stub for legacy inboxes whose channel_type is still 'Channel::Voice' after
+# the upstream DropChannelVoice migration moved voice fields onto
+# Channel::TwilioSms. Pointing at the new table lets Rails resolve
+# `belongs_to :channel, polymorphic: true` lookups to nil (no matching row),
+# so jbuilder `.try` chains short-circuit instead of raising.
+class Channel::Voice < ApplicationRecord
+  self.table_name = 'channel_twilio_sms'
+end
diff --git a/enterprise/app/models/enterprise/concerns/attachment.rb b/enterprise/app/models/enterprise/concerns/attachment.rb
index 155dfcaad..06b8b641a 100644
--- a/enterprise/app/models/enterprise/concerns/attachment.rb
+++ b/enterprise/app/models/enterprise/concerns/attachment.rb
@@ -3,13 +3,30 @@ module Enterprise::Concerns::Attachment
 
   included do
     after_create_commit :enqueue_audio_transcription
+    # Broadcast the message update so the FE bubble picks up the new audio
+    # attachment immediately. Without this, the FE has to wait until Whisper
+    # finishes (or fall back to a page refresh) — and if Whisper returns blank,
+    # the bubble never gets the audio at all.
+    after_create_commit :broadcast_message_update_for_audio
   end
 
   private
 
   def enqueue_audio_transcription
     return unless file_type.to_sym == :audio
+    return unless file.attached?
 
     Messages::AudioTranscriptionJob.perform_later(id)
   end
+
+  def broadcast_message_update_for_audio
+    return unless file_type.to_sym == :audio
+    return unless message
+    # Without an attached file, the message serializer's audio_metadata path
+    # dereferences `file.metadata[:width]` on nil and raises. The pre-attach
+    # broadcast wouldn't carry useful audio info anyway — skip until upload completes.
+    return unless file.attached?
+
+    message.reload.send_update_event
+  end
 end
diff --git a/enterprise/app/models/enterprise/conversation.rb b/enterprise/app/models/enterprise/conversation.rb
index 09cb2c569..077e0e932 100644
--- a/enterprise/app/models/enterprise/conversation.rb
+++ b/enterprise/app/models/enterprise/conversation.rb
@@ -13,6 +13,12 @@ module Enterprise::Conversation
     super + %w[sla_policy_id]
   end
 
+  # Surface call lifecycle changes to the FE: writes to additional_attributes
+  # call_status/call_direction should rebroadcast conversation_updated.
+  def allowed_keys?
+    super || call_attributes_changed?
+  end
+
   def with_captain_activity_context(reason:, reason_type:)
     previous_reason = captain_activity_reason
     previous_reason_type = captain_activity_reason_type
@@ -30,4 +36,13 @@ module Enterprise::Conversation
   def dispatch_captain_inference_event(event_name)
     dispatcher_dispatch(event_name)
   end
+
+  def call_attributes_changed?
+    return false if previous_changes['additional_attributes'].blank?
+
+    # Compare before/after values for call keys — checking key presence alone
+    # rebroadcasts on any unrelated additional_attributes write once the keys exist.
+    before, after = previous_changes['additional_attributes']
+    %w[call_status call_direction].any? { |key| (before || {})[key] != (after || {})[key] }
+  end
 end
diff --git a/enterprise/app/services/enterprise/whatsapp/providers/whatsapp_cloud_service.rb b/enterprise/app/services/enterprise/whatsapp/providers/whatsapp_cloud_service.rb
index 552c3c389..b21f58494 100644
--- a/enterprise/app/services/enterprise/whatsapp/providers/whatsapp_cloud_service.rb
+++ b/enterprise/app/services/enterprise/whatsapp/providers/whatsapp_cloud_service.rb
@@ -1,4 +1,9 @@
 module Enterprise::Whatsapp::Providers::WhatsappCloudService
+  # Calls API + the call_permission_request interactive message both require Graph
+  # API v17+; OSS phone_id_path is locked at v13.0 for legacy /messages compatibility.
+  # Use the configured global version (defaulting to v22.0) for call-flow endpoints.
+  WHATSAPP_CALLING_API_VERSION_FALLBACK = 'v22.0'.freeze
+
   def pre_accept_call(call_id, sdp_answer)
     call_api('pre_accept_call', call_action_body(call_id, 'pre_accept', sdp_answer))
   end
@@ -17,7 +22,7 @@ module Enterprise::Whatsapp::Providers::WhatsappCloudService
 
   def send_call_permission_request(to_phone_number, body_text = I18n.t('conversations.messages.whatsapp.call_permission_request_body'))
     response = HTTParty.post(
-      "#{phone_id_path}/messages", headers: api_headers, body: permission_request_body(to_phone_number, body_text)
+      "#{calls_phone_id_path}/messages", headers: api_headers, body: permission_request_body(to_phone_number, body_text)
     )
 
     unless response.success?
@@ -30,13 +35,19 @@ module Enterprise::Whatsapp::Providers::WhatsappCloudService
 
   def initiate_call(to_phone_number, sdp_offer)
     response = HTTParty.post(
-      "#{phone_id_path}/calls", headers: api_headers, body: initiate_call_body(to_phone_number, sdp_offer)
+      "#{calls_phone_id_path}/calls", headers: api_headers, body: initiate_call_body(to_phone_number, sdp_offer)
     )
     process_initiate_call_response(response)
   end
 
   private
 
+  def calls_phone_id_path
+    base = ENV.fetch('WHATSAPP_CLOUD_BASE_URL', 'https://graph.facebook.com')
+    version = GlobalConfigService.load('WHATSAPP_API_VERSION', WHATSAPP_CALLING_API_VERSION_FALLBACK)
+    "#{base}/#{version}/#{whatsapp_channel.provider_config['phone_number_id']}"
+  end
+
   def call_action_body(call_id, action, sdp_answer = nil)
     body = { messaging_product: 'whatsapp', call_id: call_id, action: action }
     body[:session] = { sdp: sdp_answer, sdp_type: 'answer' } if sdp_answer
@@ -44,7 +55,7 @@ module Enterprise::Whatsapp::Providers::WhatsappCloudService
   end
 
   def call_api(action_name, body)
-    url = "#{phone_id_path}/calls"
+    url = "#{calls_phone_id_path}/calls"
     Rails.logger.info "[WHATSAPP CALL] #{action_name} POST #{url} body=#{body.except(:session).to_json}"
     response = HTTParty.post(url, headers: api_headers, body: body.to_json)
     Rails.logger.error "[WHATSAPP CALL] #{action_name} failed: status=#{response.code} body=#{response.body}" unless response.success?
diff --git a/enterprise/app/services/messages/audio_transcription_service.rb b/enterprise/app/services/messages/audio_transcription_service.rb
index 0e574cb03..3c37df142 100644
--- a/enterprise/app/services/messages/audio_transcription_service.rb
+++ b/enterprise/app/services/messages/audio_transcription_service.rb
@@ -67,7 +67,9 @@ class Messages::AudioTranscriptionService< Llm::LegacyBaseOpenAiService
         parameters: {
           model: WHISPER_MODEL,
           file: file,
-          temperature: 0.4
+          # 0.0 minimises Whisper's hallucinations on silence / sub-vocal segments —
+          # higher temperatures produce phantom phrases that look like real transcripts.
+          temperature: 0.0
         }
       )
       transcribed_text = response['text']
diff --git a/enterprise/app/services/whatsapp/call_service.rb b/enterprise/app/services/whatsapp/call_service.rb
new file mode 100644
index 000000000..ec8205e63
--- /dev/null
+++ b/enterprise/app/services/whatsapp/call_service.rb
@@ -0,0 +1,102 @@
+class Whatsapp::CallService
+  pattr_initialize [:call!, :agent!, :sdp_answer]
+
+  def accept
+    raise Voice::CallErrors::CallFailed, 'sdp_answer is required' if sdp_answer.blank?
+
+    # All side effects under the lock so a concurrent terminate cannot finalize
+    # the call between status update and the message/conversation/broadcast writes.
+    call.with_lock do
+      transition_to_in_progress!
+      update_message_status('in_progress')
+      update_conversation_call_status(call.display_status)
+      broadcast(:accepted, accepted_by_agent_id: agent.id)
+    end
+    call
+  end
+
+  def reject
+    call.with_lock do
+      next if call.terminal? || call.in_progress?
+
+      invoke_provider!(:reject_call)
+      finalize_call('failed')
+    end
+    call
+  end
+
+  def terminate
+    call.with_lock do
+      next if call.terminal?
+
+      invoke_provider!(:terminate_call)
+      # Agent hangs up before contact picks up → no_answer; mirrors the webhook terminate path.
+      finalize_call(call.in_progress? ? 'completed' : 'no_answer')
+    end
+    call
+  end
+
+  private
+
+  def transition_to_in_progress!
+    # Order matters: in_progress and terminal both make ringing? false, so we have to
+    # branch on in_progress? first to surface the distinct AlreadyAccepted state.
+    raise Voice::CallErrors::AlreadyAccepted, 'Call already accepted by another agent' if call.in_progress?
+    raise Voice::CallErrors::NotRinging, 'Call is not in ringing state' unless call.ringing?
+
+    forward_answer_to_meta!
+    call.update!(status: 'in_progress', accepted_by_agent_id: agent.id, started_at: Time.current,
+                 meta: (call.meta || {}).merge('sdp_answer' => sdp_answer))
+    claim_conversation_for_agent
+  end
+
+  def forward_answer_to_meta!
+    invoke_provider!(:pre_accept_call, sdp_answer)
+    invoke_provider!(:accept_call, sdp_answer)
+  end
+
+  # Take ownership of the conversation if no one holds it; leave assignee alone otherwise (transfer via UI).
+  def claim_conversation_for_agent
+    call.conversation.update!(assignee: agent) if call.conversation.assignee_id.blank?
+  end
+
+  # Raise on Meta failure (bool false or transport error) so callers bail before
+  # finalizing local state — otherwise we'd mark a still-active call as ended
+  # and broadcast voice_call.ended while Meta thinks it's live.
+  def invoke_provider!(method, *)
+    success = call.inbox.channel.provider_service.public_send(method, call.provider_call_id, *)
+    raise Voice::CallErrors::CallFailed, "Meta #{method} failed" unless success
+  rescue Voice::CallErrors::CallFailed
+    raise
+  rescue StandardError => e
+    Rails.logger.error "[WHATSAPP CALL] #{method} failed: #{e.class} #{e.message}"
+    raise Voice::CallErrors::CallFailed, "Meta #{method} failed"
+  end
+
+  def finalize_call(status)
+    meta = (call.meta || {}).merge('ended_at' => Time.zone.now.to_i)
+    call.update!(status: status, meta: meta)
+    update_message_status(status)
+    update_conversation_call_status(call.display_status)
+    broadcast(:ended, status: call.display_status)
+  end
+
+  def update_message_status(status)
+    Voice::CallMessageBuilder.new(call).update_status!(status: status, agent: agent)
+  end
+
+  def update_conversation_call_status(status)
+    call.conversation.update!(
+      additional_attributes: (call.conversation.additional_attributes || {}).merge('call_status' => status)
+    )
+  end
+
+  def broadcast(event, **extra)
+    payload = {
+      event: "voice_call.#{event}",
+      data: { id: call.id, call_id: call.provider_call_id, provider: call.provider,
+              conversation_id: call.conversation_id, account_id: call.account_id }.merge(extra)
+    }
+    ActionCable.server.broadcast("account_#{call.account_id}", payload)
+  end
+end
diff --git a/enterprise/app/services/whatsapp/incoming_call_service.rb b/enterprise/app/services/whatsapp/incoming_call_service.rb
index 3b4d17378..709862230 100644
--- a/enterprise/app/services/whatsapp/incoming_call_service.rb
+++ b/enterprise/app/services/whatsapp/incoming_call_service.rb
@@ -50,7 +50,10 @@ class Whatsapp::IncomingCallService
   end
 
   def handle_terminate(payload)
-    call = Call.whatsapp.find_by(provider_call_id: payload[:id])
+    # Webhooks can arrive out of order (terminate before connect under tunnel/network
+    # delays). Materialise a missed-call record so the contact's "called and hung up"
+    # still surfaces in the dashboard instead of being silently dropped.
+    call = Call.whatsapp.find_by(provider_call_id: payload[:id]) || build_missed_inbound_call(payload)
     return unless call
 
     duration = payload[:duration]&.to_i
@@ -60,6 +63,18 @@ class Whatsapp::IncomingCallService
     broadcast(call, 'voice_call.ended', status: call.display_status, duration_seconds: call.duration_seconds)
   end
 
+  # No connect was ever processed (webhook reordering or never delivered) — build a
+  # bare Call+Message for the contact so the UI shows the missed-call bubble.
+  def build_missed_inbound_call(payload)
+    Voice::InboundCallBuilder.perform!(
+      inbox: inbox, from_number: "+#{payload[:from]}", call_sid: payload[:id],
+      provider: :whatsapp,
+      extra_meta: { 'ice_servers' => Call.default_ice_servers }
+    )
+  rescue ActiveRecord::RecordNotUnique
+    Call.whatsapp.find_by(provider_call_id: payload[:id])
+  end
+
   # accepted_by_agent_id is the initiating agent on outbound calls, so it only signals "answered" for inbound.
   def answered?(call, duration)
     call.in_progress? || duration.to_i.positive? || (call.incoming? && call.accepted_by_agent_id.present?)
diff --git a/enterprise/app/views/api/v1/accounts/whatsapp_calls/accept.json.jbuilder b/enterprise/app/views/api/v1/accounts/whatsapp_calls/accept.json.jbuilder
new file mode 100644
index 000000000..216e225e3
--- /dev/null
+++ b/enterprise/app/views/api/v1/accounts/whatsapp_calls/accept.json.jbuilder
@@ -0,0 +1 @@
+json.partial! 'api/v1/models/whatsapp_call', call: @call
diff --git a/enterprise/app/views/api/v1/accounts/whatsapp_calls/initiate.json.jbuilder b/enterprise/app/views/api/v1/accounts/whatsapp_calls/initiate.json.jbuilder
new file mode 100644
index 000000000..bdb1fa204
--- /dev/null
+++ b/enterprise/app/views/api/v1/accounts/whatsapp_calls/initiate.json.jbuilder
@@ -0,0 +1,5 @@
+json.status 'calling'
+json.call_id @call.provider_call_id
+json.id @call.id
+json.message_id @message.id
+json.provider 'whatsapp'
diff --git a/enterprise/app/views/api/v1/accounts/whatsapp_calls/reject.json.jbuilder b/enterprise/app/views/api/v1/accounts/whatsapp_calls/reject.json.jbuilder
new file mode 100644
index 000000000..db804fd57
--- /dev/null
+++ b/enterprise/app/views/api/v1/accounts/whatsapp_calls/reject.json.jbuilder
@@ -0,0 +1,2 @@
+json.id @call.id
+json.status @call.display_status
diff --git a/enterprise/app/views/api/v1/accounts/whatsapp_calls/show.json.jbuilder b/enterprise/app/views/api/v1/accounts/whatsapp_calls/show.json.jbuilder
new file mode 100644
index 000000000..216e225e3
--- /dev/null
+++ b/enterprise/app/views/api/v1/accounts/whatsapp_calls/show.json.jbuilder
@@ -0,0 +1 @@
+json.partial! 'api/v1/models/whatsapp_call', call: @call
diff --git a/enterprise/app/views/api/v1/accounts/whatsapp_calls/terminate.json.jbuilder b/enterprise/app/views/api/v1/accounts/whatsapp_calls/terminate.json.jbuilder
new file mode 100644
index 000000000..db804fd57
--- /dev/null
+++ b/enterprise/app/views/api/v1/accounts/whatsapp_calls/terminate.json.jbuilder
@@ -0,0 +1,2 @@
+json.id @call.id
+json.status @call.display_status
diff --git a/enterprise/app/views/api/v1/accounts/whatsapp_calls/upload_recording.json.jbuilder b/enterprise/app/views/api/v1/accounts/whatsapp_calls/upload_recording.json.jbuilder
new file mode 100644
index 000000000..6871426d8
--- /dev/null
+++ b/enterprise/app/views/api/v1/accounts/whatsapp_calls/upload_recording.json.jbuilder
@@ -0,0 +1,2 @@
+json.id @call.id
+json.status @upload_status
diff --git a/enterprise/app/views/api/v1/models/_whatsapp_call.json.jbuilder b/enterprise/app/views/api/v1/models/_whatsapp_call.json.jbuilder
new file mode 100644
index 000000000..0d93696c1
--- /dev/null
+++ b/enterprise/app/views/api/v1/models/_whatsapp_call.json.jbuilder
@@ -0,0 +1,24 @@
+contact = call.conversation&.contact
+
+json.id call.id
+json.call_id call.provider_call_id
+json.provider call.provider
+json.status call.display_status
+json.direction call.direction_label
+json.conversation_id call.conversation_id
+json.inbox_id call.inbox_id
+json.message_id call.message_id
+json.accepted_by_agent_id call.accepted_by_agent_id
+json.elapsed_seconds(call.started_at ? (Time.current - call.started_at).to_i : 0)
+json.sdp_offer call.meta&.dig('sdp_offer')
+json.ice_servers(call.meta&.dig('ice_servers') || Call.default_ice_servers)
+
+if contact
+  json.caller do
+    json.name contact.name
+    json.phone contact.phone_number
+    json.avatar contact.avatar_url
+  end
+else
+  json.caller({})
+end