Telephony

Phone numbers and voice transport for the AI call agents, split across three services: ms-ai owns numbers, purchase, and rental billing (src/elevenlabs/); ms-communication owns the live audio bridges and post-call persistence; backend owns the wallet ledger and the webhook fallback cron.

Carriers

Carrier	Numbers	Audio path	Credentials
Twilio	in-app purchase (per-company subaccounts) + BYO import	TwiML <Connect><Stream> → /twilio/media-stream WS → ElevenLabs	ms-ai master TWILIO_MASTER_ACCOUNT_SID/_AUTH_TOKEN creates subaccounts; BYO = per-number SID + token
Telnyx	BYO import only	TeXML <Connect><Stream> → /telnyx/media-stream WS → same bridge	per-number telnyx_api_key + telnyx_connection_id (TeXML app), stored in number meta

• Carrier is per number: elabs_phone_number.provider (twilio/telnyx) in ms-ai selects the dial path; inbound_outbound_calls.provider in ms-comm records it. ElevenLabs has no native Telnyx support — ms-ai synthesizes number_id: telnyx_<uuid> and the ms-comm bridge carries the audio.
• ms-comm Telnyx surface: TelnyxInboundCallController / TelnyxOutboundCallController + TelnyxHelper (TeXML builders). Routes: POST /telnyx/inbound-voice/:company_id, /telnyx/inbound-status/:company_id, /telnyx/outbound-voice/:company_id, /telnyx/outbound-status/:company_id, /telnyx/preheat-outbound/:company_id/:agent_id. Env: TELNYX_MEDIA_STREAM_PATH (default /telnyx/media-stream), TELNYX_PUBLIC_WS_URL (else derived from ELEVENLABS_PUBLIC_WS_URL).
• Codecs: Twilio is always PCMU (mu-law) 8k. Telnyx inbound legs are PCMU, outbound/international PCMA (A-law) — TeXML declares bidirectionalCodec per direction; AudioTranscodeHelper (A-law support) normalizes to mu-law on ingest so the rest of the bridge is unchanged.
• Live monitor/takeover is carrier-agnostic, keyed by service_room_id: both bridges fan audio + transcripts into ai-listen:<service_room_id>, served by the existing socket handlers — no Telnyx-specific sockets.

Number lifecycle (ms-ai)

Buy (Twilio only). GET /elevenlabs/available-phone-numbers/twilio → POST /elevenlabs/buy-phone-number/twilio/{inbound|outbound|sms} (+ cancel-phone-number/twilio). The UI offers US/CA/GB/AU × local/toll-free/mobile (the server accepts any ISO country, default US). The number is purchased into the company's Twilio subaccount (findOrCreateTwilioSubaccount, FriendlyName knock-sub:<company_id>; subaccount SID + token live on the number's meta). The buy is gated on the wallet covering the marked-up price (markup_percent from the wallet response; 402 when short) and the first month is charged at purchase (meta.next_rental_at starts the clock).

Billing crons — NumberRentalScheduler (src/elevenlabs/number-rental.scheduler.ts; kill switch NUMBER_RENTAL_CRON_ENABLED=false; app-purchased numbers only, BYO is never touched):

Cron name	Schedule	Does
number-rental:meter-due	daily 06:00 UTC	monthly rental debit, idempotent on twilio-rental:<number>:<period>; catches up missed months; frozen while suspended
twilio-call-cost:meter	every 10 min	sweeps each subaccount's completed calls (48h lookback), debits Twilio's settled per-call price, idempotent on twilio-call:<CallSid>
twilio-sms-cost:meter	every 10 min	twin of the call sweep for sent SMS (meterTwilioSmsCosts()), debits Twilio's settled per-message price, idempotent per Message SID
number-rental:suspension-sweep	every 15 min	suspend / warn / release lifecycle below

Suspension (state in the number's meta: suspended, suspended_at, release_at, warnings_sent): wallet < 0 → suspend, release_at = +7d, day-0 warning; day-3/day-6 warning emails; past release_at → release from Twilio; wallet back > 0 → auto-unsuspend. Emails route through backend POST /internal/telephony/notify (suspend_warning / released → subscription/number-suspended.html / number-released.html).

Inbound block. ms-comm calls GET /elevenlabs/telephony-inbound-allowed/:company_id?number= (4s timeout, fail-open) before answering; blocked callers hear "This number is temporarily unavailable. Goodbye." Only meta.source === 'app_purchase' numbers are gated.

Ops: POST /elevenlabs/internal/meter-rentals, POST /elevenlabs/internal/sweep-suspensions, GET /elevenlabs/internal/number-detail.

Telephony wallet (backend)

TelephonyWalletController (routes in app/routes/internalTelephonyRoutes.js, guarded by apiKeyAuth = BACKEND_API_KEY). The wallet is the subscription's remaining_purchased_ai_credits (1 credit = $0.01); plan remaining_ai_credits is AI-only and never pays telephony.

Route	Purpose
GET /internal/telephony/wallet/:company_id	wallet_credits, plan_credits, has_telephony (wallet > 0), ai_available (plan > 0 || wallet > 0), markup_percent
POST /internal/telephony/debit	idempotent on idempotency_key (unique in ai_credit_logs); charges base × (1 + markup) at 4-dp precision; balance may go negative (paid down by the next top-up)
POST /internal/telephony/notify	suspension/release emails to the resolved billing user

Markup: global setting telephony_markup_percent (default 0), applied on every debit (margin recorded on the ledger row) and returned so ms-ai gates the buy and the frontend shows final prices. Wallet UI: frontend/src/views/packages/Wallet.vue; buy UI in the agents' Phone Numbers tabs (markup via useTelephonyMarkup.js).

Transports

Widget AI calls — WebRTC (LiveKit). ms-comm hardcodes calling_type: 'webrtc' on POST {ms-ai}/elevenlabs/start-audio-call (CallsController); ms-ai returns a LiveKit conversation token (the websocket path still returns signedUrl) and the widget starts the ElevenLabs SDK with { conversationToken, connectionType: 'webrtc' } (widget/src/services/aiCall.ts). Feature parity runs on SDK callbacks instead of the raw socket: transcripts, typed user messages, product cards (events-gateway), booking confirmation (delivered as a userMsg — the only signal the agent gets on LiveKit), and live-listen taps the agent's LiveKit audio track into the audio_chunk stream. Token wait is 30s (was 15s); a ringback loop (on-call-ringing.mp3, started inside the click gesture in widget/src/stores/widget.ts) covers the connect gap.

PSTN. Dual-WebSocket bridge (ElevenLabsBridgeService): carrier leg (mu-law/A-law 8k) ↔ ElevenLabs Convai (PCM 16k), transcoding both ways, transcript + audio fan-out to ai-listen:<service_room_id>.

Agent-sync skip cache (web only). start-audio-call used to re-sync the ElevenLabs agent on every connect (~6.2s). ms-ai now skips the sync when nothing changed: per-replica in-memory cache keyed on a sha256 of the agent config, TTL AGENT_SYNC_CACHE_TTL_MS (default 5 min), invalidated via invalidateAgentSyncCache() on every mutating path (elevenlabs.service.ts). Telephony agents are deliberately not cached — they have preheat.

WebRTC parity fixes: service-room-update-data (stores elabs_conversation_id on the service room — the key for recordings and the transcript email) now fires on both transports, not just websocket; the widget emits ai-call-client-log → ms-comm CallsController persists client-side call diagnostics (event, transport, handshake UA) into the logs collection; transcript-email timestamps render in the company timezone.

Inbound routing priorities

Per inbound agent routing_priorities: [{ number, ring_timeout }] — ring real phones in order before the AI. Sanitized in backend AiInboundAgentController._sanitizeRoutingPriorities (max 10 numbers, timeout clamped 5–120s, default 20s); UI InboundCallAgent/CallForwarding.vue. ms-comm dials the chain with <Dial timeout=… answerOnBridge>, advancing via POST /twilio/inbound-dial-fallback/:company_id. Empty list = straight to AI; applies regardless of working hours; any error fails open to the AI. The wallet gate runs before the chain — forwarding legs cost carrier minutes too.

Inbound call screening (Twilio only)

Optional <Gather> keypress gate that runs before routing priorities, so auto-dialers never reach the AI (or a forwarded human):

• ms-comm POST /twilio/inbound-screen/:company_id sits atop handleInboundVoice. Stateless — the expected digit and agent ids ride the Gather action URL (?d=… etc.), no session store. Any error fails open to the normal flow.
• Config: per-inbound-agent agent.call_screening (sanitized in backend AiInboundAgentController._sanitizeCallScreening, normalized again in ms-comm _normalizeCallScreening).
• Failed screens land in ScreenedCallModel (screened_calls: unique call_sid upsert so webhook retries don't double-log; reason: no_input | wrong_digit; TTL index 90d). Deliberately NOT inbound_outbound_calls — a screened call has no transcript/duration and must not pollute call lists, Knox stats, briefs, or GHL sync. Screening never blocks a number; each call gets a fresh prompt.
• Latency: preheat starts during the Gather (fire-and-forget); on screened re-entry (?screened=1) the prewarm budget is 3s (vs 11s) and nothing runs before <Connect>.
• No Telnyx equivalent. Read route for the dashboard log: backend GET /ai-inbound-agents/:agent_key/screened-calls.

Voicemail detection (async AMD, outbound)

Every outbound dial now carries Twilio/Telnyx async answering-machine detection:

• ms-ai _appendAmdParams (elevenlabs.service.ts) adds MachineDetection=Enable + AsyncAmd=true + status callback — the call connects immediately, the AMD verdict arrives async.
• Callbacks: ms-comm POST /twilio/amd-status/:company_id (OutboundCallController.handleAmdStatus) and POST /telnyx/amd-status/:company_id (TelnyxOutboundCallController) — both always answer 204. Telnyx verdicts match the bridge registry by both CallSid and CallSidLegacy (Telnyx doesn't document which equals the TeXML sid).
• ElevenLabsBridgeService.handleMachineDetected acts only on machine* / fax verdicts; human / unknown are no-ops. The record's voicemail flag is written with $max — sticky true, a late human can't un-flag it.
• Env (ms-ai): AMD_ENABLED (default true), AMD_TIMEOUT_SECONDS (20), AMD_SPEECH_THRESHOLD_MS (3000). If the carrier rejects the AMD params the dial retries once without AMD. Log tag [voicemailAMD].

Cross-call memory (continuation first message)

Returning callers get a personalized opener instead of the stock greeting:

• ms-ai POST /agents/generate-first-message — public, throttled (5/s, 60/min), backed by FirstMessageAgent (modules/agents/definitions/first-message.agent.ts). Always returns 200 with the default greeting on any failure; never emits {{…}} template tokens.
• ms-comm helpers/FirstMessageHelper.js wraps the call (20s timeout — the LLM round-trip is the work, not overhead; callers bound total wait themselves).
• PSTN: ElevenLabsBridgeService._loadPriorCallTranscript keys on caller_number (index { caller_number: 1, started_at: -1 }), requires at least one caller turn, takes the last 30 turns. _getContinuationFirstMessageCached dedupes so preheat + call start share one Mongo read/LLM call. Total budget on the connect path: FIRST_MESSAGE_INIT_CAP_MS (2000) — over budget falls back to the configured greeting. Gate: per-inbound-agent continue_previous_conversation.
• Web: gate ai_config.call_continue_previous_conversation (widget opt-in). The generated opener rides the joining-ai-call payload as a per-session first_message override — never baked into the shared ElevenLabs agent. An accepted auto-trigger greeting wins over the continuation opener.

Caller authentication (inbound, 2026-09)

Inbound phone agents can verify a caller by username + password before saying anything account-specific. Three AND gates (backend/app/lib/aiAgentAuthentication.js isAuthenticationEffective): company.ai_agent_authentication_allowed (super-admin, default false) && company.ai_agent_authentication.enabled (tenant) && agent.authentication_required (per inbound agent, declared on ai_inbound_call — keep it declared or the strict subdoc strips it).

• Users: ai_agent_authentication.users (Mixed, select:false, max 500), max_attempts (1–5, default 3), failure_action (end_call | continue_without_access). Passwords are scrypt (scrypt$<salt>$<hash>, N=16384/r=8/p=1, keylen 64, salt per user) over the normalized spoken form (lowercase, whitespace and punctuation stripped — "Hunter 2" stores as "hunter2"); timingSafeEqual; an unknown username still verifies against a decoy hash so timing can't enumerate users. Rate limits in AiAgentAuthenticationService: per-conversation = max_attempts, per-company 120/60s, per-caller-number.
• Routes: tenant GET|PUT /ai-agent-authentication, POST …/users, PUT|DELETE …/users/:id (JWT); super-admin PUT /company/:_id/ai-agent-authentication-allowed; internal (apiKeyAuth) POST /internal/ai-agent/authenticate and GET /internal/ai-agent/authentication-status/:company_id — both always 200. Both ai_agent_authentication* keys are in noxConfigFieldMap.js FORBIDDEN_PREFIXES, so Nox can never write them.
• ms-ai tool company_user_authentication (hosted name companyUserAuthentication, webhook elevenlabs/tools/company-user-authentication, header secret from workspace secret COMPANY_AUTH_TOOL_AUTH — ElevenLabs drops plain-string headers). company-auth-tool.service.ts resolves the tenant from system__agent_id via elabs_agent; the company_id dynamic var is a cross-check only (company_mismatch refuses); non-inbound-telephony refused. Forwards {company_id, agent_key, username, password, conversation_id, call_sid, caller_number} and returns the backend body verbatim: {authenticated: true, instruction} or {authenticated: false, message, attempts_remaining, locked, instruction} / verification_unavailable / not_enabled. Success reveals nothing about the user.
• Prompt placement (elevenlabs.service.ts ~1494–1524, hardened in d891d7471 / bb2c9098c / d92567856): the full # Caller Verification block goes first (right after the company prompt) and a short # Before you say anything else reminder goes last, after the caller context — primacy and recency; middle-only and end-only both failed in testing. Both sit after the company prompt so the per-call refresh strip regenerates rather than accumulates. Attached only for inbound-telephony when portalTools includes companyUserAuthentication.
• ms-comm: ElevenLabsBridgeService._isAuthRequired() re-derives the three-gate rule from a projected lean read (30s cache, fails closed) and passes ?auth_required=1 on the tools refresh. Live redaction: _notePasswordPrompt arms on an agent turn matching /\bpassword\b/i, and _redactSpokenPassword replaces the next caller turn with [password redacted] before logging, socket fan-out, and transcript persistence. Post-call, ms-ai redact-auth-transcript.ts runs at the top of postCallWebhook — before webhook_inbox storage and before forwarding — scrubbing the tool's params_as_json / tool_details and the nearest preceding user turn (and original_message).
• Never persisted: the plaintext password anywhere; users is select:false and never returned to the dashboard; audit lines carry masked usernames (j***); failure messages never say which field was wrong.
• preserveInboundAgentFields (aiAgentAuthentication.js, used in CompanyController update): the default agent saves as one whole ai_inbound_call object and Mongo $set replaces the subdoc, so a browser tab holding a pre-toggle copy silently erased authentication_required (and webhook_secret) by saving a new greeting. Server-owned keys are now carried forward when omitted, then authentication_required is forced false unless ai_agent_authentication_allowed. This is a different failure mode from the strict-subdoc drop — declaring the field doesn't fix it.

Agent memory gating

Per-agent use_memory (absent = true) and continue_previous_conversation (absent = false) resolve through ms-comm AgentMemoryFlagHelper.resolveAgentFlags(companyId, {direction, agentKey}) — one cached (30s) lean read; use_memory fails open, continuation fails closed, and continuation is ANDed with use_memory. Consumed in ElevenLabsBridgeService (456970e): gates _getVisitorContextByPhoneCached and the continuation opener.

Widget voice uses ai_config.call_use_memory, resolved by CallsController._isWidgetVoiceMemoryEnabled as a deliberate .lean() raw read — ms-comm's CompanyModel is a mirror, and a hydrated read would drop the path and flip memory back on. Off also stamps _stampRoomMemoryOptOut (room excluded from fact extraction and identity-graph past_conversations) and skips _loadPriorTranscript. In ms-ai, use_memory is part of the agent-config hash so a toggle re-syncs the prompt, and memory-off withholds upsert_memory / delete_memory_slot and removes them from the instructions (memory-tool-gating.spec.ts). Outbound (telephony) agents are inert — null user_session_id, no {{visitor_context}}, useMemory hardcoded true.

Custom LLM for ElevenLabs agents

ms-ai/src/elevenlabs/call-models.ts is the single source of truth for the AI Model selector. NATIVE ids write prompt.llm = <id>; CUSTOM ids (Baseten-hosted, e.g. baseten-glm-4.7, in our namespace) write prompt.llm = 'custom-llm' plus a prompt.customLlm block built by custom-llm.service.ts pointing at BASETEN_INFERENCE_URL (https://inference.baseten.co/v1; ElevenLabs appends /chat/completions). Persisted as ai_config.call_model / ai_inbound_call_agents[].model / ai_outbound_call_agents[].model. Env: ELEVENLABS_CUSTOM_LLM_PROVIDER (default baseten), ELEVENLABS_CUSTOM_LLM_MODEL (default zai-org/GLM-4.7).

The provider API key never enters ms-ai. It exists only as a hand-created ElevenLabs workspace secret, resolved by name to a secretId and referenced as apiKey: { secretId }. The name→id map is memoised per process (promise cached, dropped on failure, cooldown before a miss re-lists) because the web path syncs on the blocking getCallUrl / getCallToken path. It never throws — a missing secret or unreachable ElevenLabs returns null and the call connects on the native server-default LLM. KNOX_VOICE_LLM=custom-llm for the Nox voice agent is intentional. GET /elevenlabs/agent/:company_id?include_prompt=1 reads system_prompt + tool_ids back off the live agent (multiple KB, so opt-in); backend liveInboundAgentFor() (app/lib/inboundAgentSync.js) uses it to show what ElevenLabs is actually holding, which differs from buildInboundSyncPayload().system_prompt by thousands of characters.

Speech settings & background sound

• company.ai_config.call_speech_settings — responsiveness (mapped to ElevenLabs turn-eagerness buckets), interruption_sensitivity (default 0.5), backchannel, audio normalization — and company.ai_config.call_background_sound (ElevenLabs-native ambience: preset track, volume/100, crossfade loop) apply to the widget/web agent.
• Telephony agents carry per-agent Mixed speech_settings / background_sound blocks on the sync DTOs (ms-ai/src/elevenlabs/dto/elevenlab-all.dto.ts), same shape.
• Gotcha fixed: updateAgent re-applies buildLanguagePresets — previously a settings update dropped the multilingual presets from the ElevenLabs agent.

SMS

Twilio SMS over the same subaccounts/numbers (purpose sms):

• ms-ai: POST /elevenlabs/send-sms (send via the company subaccount), POST /elevenlabs/compose-sms (LLM-drafted message, cost bucket KnownAgent.SMS), POST /elevenlabs/import-phone-number/twilio/sms, POST /elevenlabs/buy-phone-number/twilio/sms. Costs swept by twilio-sms-cost:meter (table above).
• Backend: SMS agents (company.sms_agents, gate sms_agents_allowed) with AiSmsAgentController CRUD, public POST /ai-sms/webhook (per-agent secret_key; actions send_sms | generate_sms), message log SmsAgentMessageModel, GHL workflow-action routes — see SMS Agent.
• POST /ai-outbound/send-sms — texts from an outbound call agent's number; signed exactly like the call webhook (webhook_secret), DNC-suppressed, relays to ms-ai send-sms. Meanwhile POST /ai-outbound/sdk-trigger is disabled — hard 403, SDK error code outbound_unavailable.

Post-call pipeline

1. ms-comm InboundOutboundCallController.saveAndEmail persists transcript/outcome. The post-call webhook is held until the ElevenLabs analysis lands (it carries summary, sentiment, recording); single-fire via an atomic claim on post_call_webhook_sent_at.
2. Backend PostCallWebhookFallbackJob (every 1 min, SchedulerService): calls still unfired 5 min after ended_at fire with what exists (max age 24h, 5 attempts, batch 50, same claim — the two paths can never both send). Its sibling CallTranscriptEmailFallbackJob (every 1 min) does the same for the transcript email, which now waits for the analysis (call_summary_title becomes the subject, the summary renders above the transcript): status: 'completed', email_sent_at: {$in: [null]}, email_fallback_attempts: {$not: {$gte: 5}} ($not/$gte, not $lt — $lt misses a missing field), 'transcript.0' exists, ended_at between now−24h and now−5min, 50 per pass → POST {ms-comm}/inbound-outbound-calls/send-transcript-email {call_sid}. The mark-sent-before-send invariant holds: email_sent_at is claimed atomically before sending and $unset on failure. Extraction is claimed by the first invocation so extracted_contact keeps the caller's real name out of "Phone caller". 2b. Live call events: on answer the bridge posts POST /call-events/live (backend CallEventsController.live, apiKeyAuth, fire-and-forget, 5s timeout) — carrier-agnostic, both directions, deduped on Redis SETNX call-events:live:<service_room_id> for 15 min (Redis blip falls through) — which fires the governed ai-call-live push to every admin device. POST /call-events/ended carries duration_seconds, stamped onto service_rooms.call_duration without overwriting; the super-admin Call Duration Backfill (POST /admin/calls/backfill-durations + jobs poll, dry-run, cursor-streamed) fills history from ms-ai GET /knox-signals/transcripts/durations. Frontend CallPanel.isEventForThisCall requires the session to match, ignores replaced_by_agent_call events, and requires a named service_room_id to be ours — a visitor's widget call can end while the agent's call to the same visitor stays live.
3. Payload (PostCallWebhookService, everything namespaced under next_level_call): agent_key, transcript[], transcript_text (joined Speaker: text), summary, call_sentiment (positive|neutral|negative, classified from the caller's words via ms-ai POST /agents/classify-call-sentiment, stored as sentiment on the record), signed recording_url.
4. Recording links: HMAC-SHA256 over <conversationId>.<exp>, TTL ~365d, secret RECORDING_LINK_SECRET, fail-closed (no secret → no link). RecordingLinkService exists as identical copies in ms-comm (mint) and backend (mint + verify) — change together. Served by backend GET /public/recordings/:id?exp&token on api.nextlevelai.site (streams from ElevenLabs, nothing stored; 403 bad signature / 410 expired). CRM inline players use the separate .mp3-suffixed GET {ms-comm}/recordings/ai/<id>.mp3 (from AiCallGhlTranscriptSyncJob).
5. Outcomes: phone call_outcome ∈ booked|qualified|voicemail|no_answer|no_outcome, upgrade-only. Widget AI calls have a separate two-value service_rooms.call_outcome ∈ booked|qualified|'' (declared in backend and ms-comm ServiceRoomModel lock-step), written by ms-comm MessageController from the ElevenLabs post-call payload: booked when a bookCalendarMeeting tool result succeeded (paired to tool_calls by id, positional fallback), else qualified when the visitor spoke; no signal → no claim. Also: the ms-comm calls list takes server-side start_date / end_date ($or over started_at and created_at when started_at is null) so the tab count and the list agree. Phone outcomes are upgrade-only (a late analysis may promote qualified → voicemail/booked, never downgrade). Outbound voicemail = ElevenLabs analysis flag OR AMD verdict (see Voicemail detection) OR transcript heuristic → record field voicemail. GHL tagging runs in the backend (POST /internal/ai-call/contact-extracted applies the agent's post_call_tags; inbound built-ins are booked/qualified only), idempotent via ms-comm's post_call_tags_applied flag on the call record.
6. GHL recordings + notes are cron-driven in the backend: ms-comm stamps ghl_recording_state='pending'; GhlCallRecordingAttachJob (every 5 min) consumes it and attaches the recording to the GHL contact; GhlCallNotePostJob (every 1 min) posts call notes, deferring inbound notes until the summary lands. Shared libs backend/app/lib/callRecordingUrl.js / callNoteBody.js / ghlErrors.js. ms-comm GET /inbound-outbound-calls/:id falls through to a call_sid lookup when :id isn't a Mongo id.

Human escalation

Bridge tool escalateToHuman (ElevenLabsBridgeService._handleEscalateToHuman; the widget websocket path still registers the legacy esclateToHuman spelling):

• Destination = the agent's transfer_number read live from Mongo (default agent on ai_inbound_call, others in ai_inbound_call_agents[]); blank → company.phone_number.
• Mixed accounts: credentials resolve per dialed number via ms-ai GET /elevenlabs/inbound-company-phone/:company_id?number= — BYO-imported and platform-bought (subaccount) numbers each transfer with their own creds.
• Caller-ID pass-through: inbound transfers present the original caller's number; on carrier reject (Twilio 13223/21212, or Telnyx) retry once with the owned number. Outbound always presents the owned number.
• Twilio: Calls.update with <Dial timeout="30" answerOnBridge="true">; Telnyx: TeXML call-update REST (POST /v2/texml/calls/:sid/update). Both pause ~1.2s so the "transferring you now" TTS finishes.

Related

Call Agent · Inbound Call Agent · Outbound Call Agent · SMS Agent · Calls · AI Credits