Programmable voice calls with advanced features.
99.9%
Call Success Rate
96.5%
Speech Accuracy
<120ms
Global Latency
50k+
Active Channels
SMSLY Voice API is powered by a globally distributed cluster of SIP and RTP media servers. The architecture handles call control commands (dial, record, play, gather DTMF) in real-time. By separating the signaling path (SIP) from the media path (RTP), we ensure that high-bandwidth voice streams are routed through the closest regional edge proxy, keeping round-trip latency to a minimum and preventing audio lag.
Audio quality is highly sensitive to network jitter and packet loss. SMSLY maintains a multi-region SIP mesh with edge points of presence (PoPs) in major metropolitan hubs. These PoPs connect directly to tier-1 carriers using redundant fiber connections. The platform dynamically measures packet loss and utilizes jitter-buffer algorithms to reconstruct audio streams, maintaining clear voice quality even over degraded mobile connections.
When a voice call is placed, SMSLY's voice routing engine evaluates active carrier paths for cost and SIP response codes. If a route returns a busy signal, connection timeout, or low audio quality score, the system automatically redirects the call through a secondary carrier network in under 120ms. This least-cost, high-reliability routing keeps call completion rates above 99.9%.
Recording calls requires adherence to regional consent laws and data security standards. SMSLY Voice API offers built-in dual-channel recording. Audio files are encrypted at rest using AES-256 and stored in HIPAA-compliant object stores. The platform also provides automatic silence detection and redacted transcripts, helping finance and healthcare organizations meet strict compliance guidelines.
Modernize customer support with programmable Interactive Voice Response (IVR). SMSLY makes it simple to construct multi-level phone menus, integrate neural text-to-speech in 40+ languages, and process DTMF inputs. By automating routine inquiries and integrating with CRM platforms, enterprises can reduce call handle times and save up to 40% on operating expenses.
Every feature designed for reliability at scale. No compromises.
Fully programmable call control for making, receiving, and managing voice connections globally.
Build complex, multi-level phone menus with DTMF keypress detection and custom routing logic.
Securely record inbound and outbound calls with automatic storage encryption and retrieval APIs.
Generate natural-sounding speech in over 40 languages and multiple accents using advanced neural TTS engines.
Transcribe calls as they happen, supporting speaker diarization to separate multiple voices.
Seamlessly connect your local enterprise PBX or VoIP systems directly to the global PSTN.
Host secure, high-capacity audio conference rooms with up to 250 participants and moderator tools.
Analyze speech patterns and voice prints to identify and verify users in real-time.
Filter out voicemail boxes and answering machines to connect agents only to live answers.
Control active calls dynamically using webhook callbacks that respond to DTMF inputs or call events.
Drop-in SDKs for every major language. One API call to get started.
Build cloud contact center experiences with intelligent call routing, queue management, and agent dashboards.
Run automated outbound call campaigns for appointment reminders, payment collection, and customer surveys.
Add click-to-call buttons to your website or app. Connect customers to sales or support agents with one tap.
Deliver OTP codes via automated voice calls for users who cannot receive SMS or prefer voice delivery.
Provision a voice-enabled phone number from the SMSLY dashboard or API.
Use our Call Control API or visual flow builder to define what happens when calls are made or received.
Receive real-time webhooks for call events — ringing, answered, DTMF input, recording ready — and respond dynamically.
SOC 2 Compliant
Audited annually
Encryption at Rest
AES-256
99.95% Uptime SLA
Guaranteed
Multi-Region
3 regions active
Build a complete infrastructure stack with products designed to work together.
Start with our free tier — no credit card required. Scale to millions of messages with enterprise support, custom SLAs, and dedicated infrastructure.
Free tier includes 1,000 emails/month. No credit card required. Enterprise plans include dedicated IPs, custom SLAs, and 24/7 support.