Symbl.ai's Async API provides a REST interface for submitting recorded or saved conversations to be processed asynchronously, with the ability to retrieve job status and completion via webhooks. To use the API, developers must register for an account, authenticate using their appId and appSecret, and establish a WebSocket endpoint for live transcription. The webhook URL parameter is used to receive automatic updates on job status, and servers must respond with a 200 or 201 status code upon receipt of successful POST requests. A sample implementation of a simple Node.js server using Express is provided, which can be used as a starting point for handling webhooks and interacting with the Async API. Once a status: 'completed' event is received, conversation transcripts and insights are available via the Conversation API, and additional logic can be added to automate this process.