Desktop app
The Frontier Desktop app provides the real-time coaching interface for sales representatives, consisting of two distinct windows: a main Launcher for managing calls and a Heads-Up Display (HUD) overlay for live coaching during calls. This Electron-based client is the primary user interaction point for the Frontier system.
The Launcher (Main Window)
Section titled “The Launcher (Main Window)”The Launcher, implemented as an Electron application, serves as the primary interface for sales representatives before and after calls. This window handles user sign-in and provisioning, allowing reps to prepare for upcoming calls by reviewing scripts or relevant information. It also provides access to summaries of past calls, offering insights and a historical record of coaching interactions.
The Heads-Up Display (HUD)
Section titled “The Heads-Up Display (HUD)”During a live call, the Desktop app seamlessly transitions to display the Heads-Up Display (HUD). The HUD is a frameless, always-on-top overlay that provides real-time coaching cues directly to the rep. It dynamically displays the current sales script, highlights detected questions from the prospect, and offers quick answers or relevant information based on the live conversation. The HUD itself is a Vite/React web application embedded within the Electron client, with shared logic residing in hud-core.
When a meeting is detected, the Desktop app transitions from the Launcher to display the HUD, using internal window management utilities to show and focus the HUD window, making it click-through so it doesn’t interfere with the underlying meeting application. For a detailed walkthrough of this process, refer to How a call works.
Audio Capture and Processing
Section titled “Audio Capture and Processing”The Desktop app is responsible for capturing call audio directly from the representative’s machine for real-time transcription and coaching.
Currently, audio capture is managed by the Recall Desktop SDK from Recall.ai, which runs within the Electron application. This SDK captures meeting audio locally on the rep’s machine.
Frontier is actively migrating to a direct mic + speaker capture approach. This direct audio path, when enabled (gated by a USE_DIRECT_AUDIO flag), allows for complete separation of the rep’s audio feed from the customer’s audio. The app taps into system audio via CoreAudio loopback (on macOS) and the rep’s microphone. This raw, dual-feed audio is then streamed to Deepgram for high-fidelity speech-to-text transcription.
The transcribed audio and any subsequent coaching signals are then processed by the Call Server, where a dedicated TranscriptStreamAgent Durable Object handles the direct audio transcription and forwards events to the main per-call orchestrator. The resulting coaching cues are then delivered back to the HUD in real-time.