The Chat Interface: Streaming, Preview Rail, and History

The Main Chat Window

The chat window is where you spend most of your time in the Desktop app. It looks like a familiar chat interface -- a message history above, a composer box below -- but several features distinguish it from a simple chat UI.

Responses stream in real time, showing each token as it is generated. Alongside the text, Hermes surfaces structured summaries of tool activity as it happens. When the agent reads a file, you see a collapsible block showing the file path and the relevant excerpt. When it makes a web request, you see the URL and a summary of what was retrieved. When it runs code, you see the command and the output. You do not need to scroll through raw tool output to understand what the agent is doing -- the Desktop app presents tool activity in a clean, scannable format inline with the conversation.

This real-time visibility is one of the most practical advantages of the Desktop over the terminal. In a terminal session, tool output can scroll by quickly and get lost in the history. In the Desktop, tool activity is organized and persistent in the conversation view.

The Preview Rail

The right side of the Desktop interface is the preview rail -- a persistent panel that renders content alongside the conversation. When the agent fetches a web page, the preview rail can show you the rendered page. When it creates or edits a file, the preview rail shows the file content. When it generates an image or produces a data visualization, the preview rail renders it.

The preview rail is not just a passive display. It updates as the agent works. If the agent edits a file in several steps, the preview updates after each step, showing you the current state of the file. If the agent navigates to different URLs, the preview follows. You can watch the agent's work unfold in real time without leaving the chat.

You can also interact with the preview rail independently of the conversation. Click on a link in a rendered web page, scroll through a long file, or zoom into an image -- the preview rail is a real rendering environment, not a screenshot. This makes it useful for verifying that tool outputs look correct before accepting the agent's conclusion that the work is done.

The preview rail is particularly valuable for development workflows. With a file browser in the rail showing your project directory and the preview showing the current state of a file the agent is editing, you can follow along with coding tasks at a level of detail that would require constant tab-switching in a terminal workflow.

Drag-and-Drop File Attachment

Anywhere in the chat area, you can drag a file from Finder (or Windows Explorer, or your Linux file manager) and drop it directly into the chat. Hermes attaches the file to your next message. The agent can then read the file, analyze its contents, transform it, or use it as context for your request.

Drag-and-drop is the fastest way to give the agent access to a specific file without navigating the file system verbally or typing a file path. It is especially useful for one-off tasks: "Review this PDF and summarize the key findings" is faster to execute by dragging the PDF into the chat than by setting the working directory, navigating to the file, and referencing it by path.

The file is attached to the specific message you are composing. It is not added to the working directory or persisted as a project file. If you need the agent to be able to reference the file across multiple turns, it is better to set the working directory to the folder containing the file using hermes desktop --cwd /path/to/folder.

Composer History: Arrow Keys to Navigate

The composer -- the input box where you type prompts -- maintains a history of everything you have sent in the current session. Use the up and down arrow keys to navigate through your previous prompts, exactly like shell history in a terminal.

This is more useful than it might sound. When you are iterating on a prompt -- adjusting a specific part of the request, trying different phrasings, or re-running a previous instruction with a small change -- navigating history with the arrow keys is much faster than retyping. Press up to recall the previous prompt, edit the part you want to change, and send the revised version.

You can also navigate to an older prompt and send it again unchanged, which is useful for repeating the same task in a different session context. The history persists for the duration of the session but does not carry over to new sessions.

The YOLO Toggle

By default, Hermes asks for confirmation before taking potentially risky actions: deleting files, running shell commands, making network requests. This approval flow is a safety feature that prevents the agent from taking unintended actions without your review.

The YOLO toggle (visible in the status bar at the bottom of the chat window) disables these approval prompts for the current session. When YOLO is active, Hermes proceeds with all tool calls automatically without waiting for confirmation.

This is appropriate for trust-established workflows where you are familiar with what the agent will do and the approval prompts are slowing you down. It is inappropriate for exploratory work where you are not sure what the agent might decide to do, for work on production systems where a mistake has real consequences, or when working in directories that contain important files you cannot afford to lose.

The YOLO toggle is per-session. Closing the chat and starting a new session resets it to the default (approval prompts active). There is no way to make YOLO the permanent default from the Desktop UI -- this is intentional, ensuring you consciously enable it each session rather than leaving it on accidentally.

Shared Conversation History Across Surfaces

Sessions created in the Desktop app are accessible from the CLI and vice versa. If you start a task in the Desktop, you can continue it from a terminal by referencing the session ID. If you close the Desktop, your conversation history is preserved and available when you re-open the app or access Hermes from the terminal.

This cross-surface history is one of the most practically useful aspects of the shared-core architecture. You are not locked into the interface you started on. If you begin a task in the Desktop but need to run a batch job that builds on the context you established, the CLI can pick up from the same session.