What’s in This SDK?
SDK Purpose
The Click To Call SDK helps developers:- Establish real-time voice calls between a user’s browser and Cognigy Voice Gateway using SIP signaling and the WebRTC API.
- Manage the full call lifecycle through a simple, promise-based API.
- Handle remote audio playback automatically.
- Receive real-time transcription events during calls, with automatic separation from regular info messages.
Requirements
| Requirement | Details |
|---|---|
| Language | JavaScript or TypeScript. The SDK works with any framework, including React, Angular, Vue, or vanilla JS. |
| Node.js | 18 or later |
| Package manager | npm |
| Browsers | Modern web and mobile browsers. For more information, refer to Supported Browsers. |
| Network | HTTPS or localhost. WebSocket and UDP traffic must be allowed. |
| Backend | A Cognigy.AI Flow with a configured Voice Gateway Endpoint. |
Use Cases
- Build multimodal browser-based voice interfaces that connect to Cognigy AI Agents.
- Embed click-to-call functionality into web applications or customer portals.
- Display real-time transcription of voice conversations in your UI.
- Integrate voice calling into existing React, Angular, Vue, or vanilla JS applications without framework lock-in.
Key Features
| Feature | Description |
|---|---|
| Custom Audio Handling | The automatic audio playback uses an internal Audio element. For advanced use cases, enable captureAudio: true in the client config to receive the raw MediaStream. The audioEnded event signals when playback stops. See Custom Audio. |
| Full Call Control | The complete call management includes start, end, mute, unmute, and info messages as async methods. See API Reference. |
| Multimodality | The multimodal interactions combine voice, text, and structured data in real time. The sendInfo method allows sending text and optional structured data during calls. See API Reference: sendInfo. |
| Event-Driven Architecture | The event system provides 17 events covering connection state, call state, audio, transcription, and errors. See Event Reference. |
| Real-Time Transcription | The transcription events are received during calls and automatically filtered from regular info messages. See Event Reference: transcription. |
Changelog Reference
The latest SDK version is available on npm as@cognigy/click-to-call-sdk. For updates and fixes, refer to the Cognigy Click To Call SDK GitHub repository.
License
The Cognigy Click To Call SDK is licensed under the MIT License.What’s Next?
- Install the SDK, create a client, and make your first voice call
- Learn how the SDK authenticates
- Explore all methods, configuration options, and types
- Discover events with callback signatures and examples
- Transport encryption, credential handling, and best practices
- Find solutions for common connection, call, and browser issues