Perplexity Comet is an agentic browser that allows an AI model to interact with web pages autonomously. The article breaks down Comet's architecture into several key components: the Perplexity API backend, the user interface (UI), custom Chrome extensions, and the Chromium-based browser itself. Each part plays a distinct role in the functioning of the system. The use of Chrome extensions is intentional; they provide a secure framework for interacting with web pages. The UI, specifically the Sidecar, is a critical element. It serves as an intermediary between the AI backend and browser extensions, managing communication and initializing tasks. When the AI needs to perform actions on a webpage, it routes requests through the Sidecar. This architecture supports a dual-channel communication system, separating the conversational UI from the browser automation tasks. The Sidecar uses Server-Sent Events (SSE) for real-time updates while employing WebSocket connections for high-frequency interactions with the browser. Three custom Chrome extensions facilitate browser automation. The comet-agent is responsible for executing commands on live web pages, while the perplexity.crx extension manages tab lifecycles and integrates various services. The third extension, comet_web_resources.crx, acts as a local CDN for static assets. The article highlights the importance of security, particularly through hard boundaries that restrict navigation to sensitive internal pages, ensuring the system operates safely.