Harnss
A cross-platform desktop app that runs Claude Code, Codex and other Agent Client Protocol-compatible agents side by side, with rich tool-call visualization, an integrated terminal, git and MCP server management.
Harnss gives a single interface for running, managing and switching between multiple AI coding agents without losing context, sessions or tool state. Each session keeps its own state and history; tool calls render as interactive cards with word-level diffs and syntax highlighting for file edits, inline bash output, and nested step-by-step progress for subagent tasks.
It connects any MCP server per project over stdio, SSE or HTTP, handling OAuth automatically and rendering some integrations, such as Jira and Confluence, with dedicated UIs. A built-in terminal, browser, git panel and file panels are scoped per project, and git operations (stage, commit, push, branches, worktrees) are available without leaving the app. The project notes it is currently pending a large rewrite and is in early development.