How do I pass authentication credentials in my HTTP requests?

Include an Authorization header containing your API key formatted as a Bearer token.

Are there official AI Voice SDK packages available?

Yes. We maintain actively updated packages for Python, Node.js, Java, PHP, Go, and C#.

Can I build healthcare tools using this Voice AI API?

Yes. Our infrastructure complies with HIPAA standards, and we sign BAAs for enterprise clients managing PHI.

What is the average audio round-trip time?

We optimize edge routing to keep total system latency beneath the 500-millisecond threshold, preserving natural conversational flow.

Am I required to bring my own SIP trunk (BYOC)?

No. Our platform includes native telecom routing. However, you can connect existing Twilio or bandwidth trunks if you prefer.

Can I map variables from the Conversational AI API directly to Salesforce?

Yes. Native integration maps extracted JSON variables to custom Salesforce fields without middleware like Zapier.

How do I verify webhook payloads are actually from OnDial?

Every webhook contains an X-OnDial-Signature. Compute a SHA256 HMAC of the raw request payload using your webhook secret and compare it to the header.

Can the AI Phone Call API transfer users to external call centers?

Yes. Using the transfer endpoint or agent logic, the system can execute a SIP transfer to any external E.164 phone number.

What are the concurrency limits for enterprise accounts?

Enterprise limits are highly scalable. We comfortably support configurations exceeding 10,000 simultaneous active channels.

Enterprise AI Voice Agent API | Fast & Scalable

Quick Answer

What is the OnDial AI Voice Agent API?

The OnDial AI Voice Agent API is a developer-focused REST and WebSocket interface for programming inbound and outbound conversational bots. It handles telecom routing, speech-to-text, natural language processing, and text-to-speech rendering, allowing engineering teams to automate enterprise phone calls and synchronize extracted data directly into custom backends.

API Overview

Built for modern software architecture

Fits cleanly into CI/CD pipelines and microservices - from number provisioning to real-time audio streaming.

REST Architecture

Standardized HTTP methods for configuration, phone number provisioning, and campaign management.

WebSocket Connections

Full-duplex bi-directional streaming for raw audio buffering and real-time transcript delivery.

Real-Time AI

Proprietary routing keeps round-trip audio latency under 200 milliseconds.

AI Calling

Fully programmable state machines for inbound answering and outbound dialing.

Voice Streaming

Inject custom audio or bypass TTS to stream your own synthesized audio to the caller.

CRM Integration

Native JSON mapping pipelines that format call data for enterprise CRM platforms.

Webhooks

Asynchronous HTTP callbacks that notify your servers the moment a call state changes.

Authentication

Bearer tokens and HMAC signature validation for high-security server-to-server access.

Why Choose OnDial API

Enterprise control without telecom overhead

Compare our infrastructure to traditional telecom providers or basic wrapper tools - the engineering advantages are clear.

Enterprise Ready

Architecture supports upwards of 10,000 simultaneous active channels per account with no core-process throttling.

Low Latency

Media servers across multiple AWS and GCP edge locations minimize physical distance to the caller.

Global Infrastructure

Provision local phone numbers in over 60 countries with a single API call.

100+ Languages

Native dialect support with auto-detection that can switch languages mid-conversation.

Human Handoff

Clean SIP transfers - dial a human operator and bridge the call when logic dictates.

Analytics

Granular JSON datasets covering silence periods, interruption rates, and goal completion.

Security

AES-256-GCM for stored assets and TLS 1.3 for all data in transit.

Compliance

Audited for SOC 2 Type II, HIPAA (with BAA), GDPR, and PCI DSS.

API Features

Programmable voice capabilities for every workflow

AI Voice Calling API

Manage the full telecom session lifecycle - dial, prompt, listen, and process audio with barge-in support and mid-session parameter updates.

Appointment Scheduling API

Feed real-time calendar availability via JSON so the agent can negotiate meeting times and lock slots with a POST back to your server.

Lead Qualification API

Define boolean qualification trees that extract budget, timeline, and authority - returning a structured lead score in the final webhook.

CRM Integration API

Format extracted variables into Salesforce, HubSpot, or custom database payloads the moment the call disconnects.

Smart Analytics API

Aggregate sentiment shifts, interruption moments, and conversational goal success rates beyond basic duration metrics.

Call Recording API

Control media capture programmatically - pause during sensitive input and retrieve signed dual-channel WAV or MP3 URLs.

AI Receptionist API

Map verbal requests to a directory and transfer to extensions or departments without a human switchboard.

Voice Bot API

Deploy single-task agents for password resets, shipping status, or account balances with tightly scoped logic.

Sentiment Detection API

Detect frustration in near real time and fire emergency webhooks to force live-agent takeover.

Workflow API

Chain answered calls into multi-channel sequences - webhooks, SMS, and follow-up actions across providers.

Human Transfer API

Bridge mid-call via SIP when questions fall outside the bot's knowledge parameters.

Quick Start

First request in under five minutes

Create Account
Register your developer profile in the OnDial dashboard.
Generate API Key
Open the Developers tab and generate a production secret. Copy it immediately - it is shown once.
Authentication
Include Authorization: Bearer <YOUR_API_KEY> on every request.
Make First Request
POST to /v1/calls/outbound with a destination number and agent prompt in the JSON body.
Receive Response
The server returns 201 Created with a unique call_id for the session.
Deploy Webhooks
Expose a local server, register the URL in webhook settings, and stream live call events.

Authentication and Security

Secure server-to-server access by default

All interactions with OnDial infrastructure require strict authentication.

API Keys

Standard secret keys for server-to-server authorization. Never embed them in client-side apps or public repositories.

Bearer Tokens

Format headers exactly as Authorization: Bearer sk_live_…

Content Type

Every POST, PUT, and PATCH request must include Content-Type: application/json.

OAuth 2.0

Reserved for partners building marketplace apps. Standard enterprise implementations should use API keys.

Production

https://api.ondial.ai/v1

Standard billing rates

Sandbox

https://sandbox.ondial.ai/v1

Free testing; audio is watermarked

URI path versioning is active on v1. Breaking changes follow a 12-month deprecation cycle with engineering contact notices.

API Endpoints

Core endpoints for agents, calls, and integrations

MethodEndpointTitleDescription

POST
/v1/agents
Create AI Agent
Compile system prompt, voice characteristics, and behavioral rules into a reusable agent ID.
POST
/v1/calls/config
Create Call Configuration
Draft a session without dialing - useful for pre-loading variables before outbound campaigns.
PATCH
/v1/numbers/{number_id}
Inbound Call Routing
Bind a purchased number to a specific agent instead of a generic holding queue.
POST
/v1/calls/outbound
Outbound Call Execution
Dial a destination in E.164 format and attach an agent when the call is answered.
POST
/v1/calls/{call_id}/transfer
Transfer Active Call
Bridge the current session to a target SIP URI or phone number.
POST
/v1/calls/{call_id}/hangup
End Call
Terminate the session immediately and trigger the final summary webhook.
GET
/v1/analytics/agents/{agent_id}
Fetch Analytics
Pull historical minutes, average duration, and error rates for a time range.
POST
/v1/webhooks
Register Webhook
Add a destination URL and subscribe to the events your system needs.
PATCH
/v1/calls/{call_id}/voice
Update Voice Configuration
Alter speaking rate or pitch dynamically during an active call.
PATCH
/v1/calls/{call_id}/language
Language Selection
Disable auto-detect and force a specific locale such as fr-CA.
POST
/v1/calls/{call_id}/sync
Trigger CRM Sync
Bypass normal delay and immediately POST call data to your CRM integration.
POST
/v1/integrations/calendar/book
Post Appointment Data
Inject extracted scheduling data into connected Google or Outlook accounts.
GET
/v1/calls/{call_id}/qualification
Fetch Lead Qualification
Return a boolean array of which required questions the caller answered positively.
POST
/v1/notifications
Trigger Notifications
Send SMS or email alerts to admins based on call events.
GET
/v1/calls/{call_id}/summary
Retrieve Call Summary
Return the transcript array and an LLM-generated executive summary.

SDKs

Official packages for your stack

Skip raw HTTP when you can. Use an official OnDial SDK for your preferred language.

Python

pip package

Node.js

npm package

Java

Maven package

PHP

Composer package

Go

go get package

C#

NuGet package

Webhooks

Real-time call state for your architecture

Webhooks push state changes to your systems as the conversation unfolds.

Webhook Events

Critical events include call.ringing, call.answered, speech.user_started, speech.agent_responded, and call.completed.

Retry Logic

On 4xx or 5xx responses, delivery retries up to 5 times with exponential backoff across 24 hours.

Security & Validation

Every payload includes X-OnDial-Signature. Verify with HMAC SHA256 of the raw body using your webhook secret.

Voice Workflow Architecture

From speech to response in under 200ms

Step 010ms
0ms
User speaks into their phone.
Step 0220ms
20ms
Audio packets travel through the SIP trunk to the OnDial ingress node.
Step 0370ms
70ms
STT engine transcribes raw audio bytes into text.
Step 04120ms
120ms
Text is processed by the designated LLM using your agent system prompt.
Step 05160ms
160ms
LLM streams tokens to the TTS engine.
Step 06190ms
190ms
Synthesized audio is pushed back through the telecom trunk.
Step 07Async
Async
After the reply, a background webhook logs the interaction and syncs data to your CRM.

Integrations

Connect voice data to your stack

Salesforce

Map custom fields via AppExchange to log activities against Leads or Contacts.

HubSpot

Automate call timeline events with embedded audio players.

Zoho

Push transcript data bi-directionally to keep support tickets updated.

Zendesk

Open tickets automatically when callers select support options.

Twilio

Bring Your Own Carrier - connect existing SIP trunks to OnDial AI logic.

Microsoft Teams

Fire Adaptive Cards into channels when high-value clients call in.

Google Calendar

OAuth into Workspace accounts so the bot can read free/busy arrays.

Slack

Route sentiment-warning notifications directly to manager channels.

Security Protocol

Hardened at every layer

Encryption Standards

AES-256-GCM for databases. TLS 1.3 for API transit.

SOC 2 Type II

Continuous independent auditing for security, availability, and processing integrity.

GDPR Compliance

Endpoints for data redaction and complete user deletion to satisfy Right to be Forgotten.

HIPAA Availability

Signed BAAs for healthcare teams plus automatic PHI redaction in text logs.

Network Protections

Strict IP allowlisting so API requests only originate from known server blocks.

Rate Limiting

Configure concurrency caps in the dashboard to protect downstream infrastructure.

Performance Metrics

Built for natural conversation at scale

Response latency so bots don't talk over users: < 200ms
Availability SLA with financially backed credits: 99.99%
Concurrent sessions per enterprise tenant: 10,000+
Media nodes across US, EU, and AP regions: Global

Industry Use Cases

Solve distinct architectural challenges by vertical

Enterprise Sales

Build a predictive dialer for thousands of stale leads. Transfer to an Account Executive only when the prospect says yes.

Healthcare Logistics

Verify identity with date-of-birth checks and confirm MRI appointments against patient databases.

Insurance Processing

Take FNOL calls at 2 AM, extract policy details, and push claims data directly into the system.

Real Estate Routing

Catch Zillow or Redfin inbound calls, parse listing IDs, and read back current asking prices.

Banking Verification

Call users immediately on suspicious charges and capture verbal confirmation or denial.

API Comparison

How OnDial compares

Feature	OnDial API	ElevenLabs	Bland AI	Vapi	Retell AI	Deepgram
Core Architecture	Enterprise Voice Agent API	TTS Generation	General Calling	Voice UI	Conversational AI	STT / Audio
HIPAA / BAA Support	Yes (Standard)	Varies	Yes	Varies	Yes	Yes
WebSocket Latency	< 200ms	N/A	~600ms	~500ms	~500ms	N/A
Direct DB/CRM Mapping	Yes (Native)	No	Limited	No	Limited	No
SIP Bridge Routing	Yes (Full Control)	No	Yes	Yes	Yes	No
Bring Your Own LLM	Yes	No	No	Yes	Yes	No

Developer FAQ

Frequently asked questions

Common questions from teams integrating the OnDial Voice Agent API.

Yes. You can point purchased numbers to your webhooks for inbound handling, and use the /v1/calls/outbound endpoint to generate calls programmatically.

Ready to Build

Ready to build with the OnDial API?

Stop spending engineering hours on telecom plumbing. Generate sandbox keys and initiate your first programmatic call in minutes.

Book Demo

Talk to a Solution Architect

REST Architecture

WebSocket Connections

Real-Time AI

AI Calling

Voice Streaming

CRM Integration

Webhooks

Authentication

Enterprise Ready

Low Latency

Global Infrastructure

100+ Languages

Human Handoff

Analytics

Security

Compliance

AI Voice Calling API

Appointment Scheduling API

Lead Qualification API

CRM Integration API

Smart Analytics API

Call Recording API

AI Receptionist API

Voice Bot API

Sentiment Detection API

Workflow API

Human Transfer API

Create Account

Generate API Key

Authentication

Make First Request

Receive Response

Deploy Webhooks

API Keys

Bearer Tokens

Content Type

OAuth 2.0

Create AI Agent

Create Call Configuration

Inbound Call Routing

Outbound Call Execution

Transfer Active Call

End Call

Fetch Analytics

Register Webhook

Update Voice Configuration

Language Selection

Trigger CRM Sync

Post Appointment Data

Fetch Lead Qualification

Trigger Notifications

Retrieve Call Summary

Python

Node.js

Java

PHP

Go

C#

Webhook Events

Retry Logic

Security & Validation

Salesforce

HubSpot

Zoho

Zendesk

Twilio

Microsoft Teams

Google Calendar

Slack

Encryption Standards

SOC 2 Type II

GDPR Compliance

HIPAA Availability

Network Protections

Rate Limiting

Enterprise Sales

Healthcare Logistics

Insurance Processing

Real Estate Routing

Banking Verification