Best for
- Developers who need to manage multiple AI coding agents in parallel
- Users who want to see what agents actually do with rich visualizations
- Teams that need integrated terminal, browser, and git workflows in one place
H
28FMRS · D
Harnss is a feature-rich open-source desktop client that aims to unify management of multiple AI coding agents. It offers excellent tool visualization and integration, but is still early in development with stability concerns.
Harnss is a cross-platform desktop app that gives you one interface to run, manage, and switch between AI coding agents — Claude Code, Codex, and any ACP-compatible agent — without losing context, sessions, or tool state. It features rich tool visualization, MCP server management, built-in terminal, browser, git, and more.
Tools
The tool list has not been reviewed yet.
Setup
Download the latest release from the Releases page, open the app, select or create a project folder, then choose an engine (Claude Code, Codex, or an ACP agent) to start working.
Fit and risk
Not for
- Casual users needing a simple CLI tool
- Users seeking production-ready stability (currently early development)
- Users uncomfortable with unsigned binaries
Required permissions
- Access to local filesystem (open projects, read/write files)
- Execute local commands (via built-in terminal and agent engines)
- Network access (for MCP server communication and agent APIs)
- System notifications (for approval requests, etc.)
- Microphone (for voice input, optional)
Risks and side effects
- Early development stage; bugs and instability may occur
- Pre-built binaries are unsigned, triggering OS warnings
- Agents can execute arbitrary code; permissions should be carefully controlled
- Reliance on third-party agents and MCP servers may introduce security risks
Troubleshooting
- Ensure Codex CLI is installed and API keys are configured
- Check MCP server configuration (transport, URL) for correctness
- On macOS, right-click the app and select 'Open' to bypass Gatekeeper on first launch
- Consult GitHub Issues or report new issues
Use cases
Run multiple AI coding agent sessions side by side
Visually inspect tool calls and file changes
Manage projects with built-in terminal, browser, and git panels
Connect MCP servers to extend agent capabilities
Supported clients
Supported clients have not been confirmed yet.