Show HN: Emdash – Open-source agentic development environment

Source: Hacker News

Introduction

Hey HN! We’re Arne and Raban, the founders of Emdash (GitHub repository).
Emdash is an open‑source, provider‑agnostic desktop app that lets you run multiple coding agents in parallel, each isolated in its own Git worktree, either locally or over SSH on a remote machine. We call this an Agentic Development Environment (ADE).

You can see a 1‑minute demo here:

Why We Built It

While building a cap‑table management application (think Stripe Atlas + Pulley), we found our development workflow to be messy:

• Lots of terminals
• Numerous branches
• Too much time waiting on Codex

Emdash puts the terminal at the center and makes it easy to run multiple agents at once. Each agent runs as a task in its own Git worktree, allowing you to start one or several agents on the same problem, test, and review.

Core Features

Parallel Agent Execution

• Run any number of agents concurrently, each in an isolated worktree.
• Agents can be executed locally or over SSH, so you can keep the workflow close to where the code lives.

Fast Task Startup

• A small reserve of pre‑created worktrees is kept in the background.
• New tasks claim a ready worktree instantly, reducing start time to ≈ 500–1000 ms (depending on the provider).
• The shell is spawned directly, bypassing heavy environment loading.

Provider‑Agnostic CLI Integration

• Supports 21 coding‑agent CLIs today, including Claude Code, Codex, Gemini, Droid, Amp, Codebuff, and more.
• Auto‑detects installed CLIs; new providers can be added on demand.
• Relies on native provider CLIs, ensuring full capability and future‑proofing (e.g., plan mode support).

Full Development Loop Inside Emdash

• Review diffs, commit, open PRs, view CI/CD checks, and merge directly from the app.
• Pass issues from Linear, GitHub, and Jira to an agent when starting a task.
• Supports convenience variables and lifecycle scripts for tasks such as port allocation and test execution.

Availability

• Open‑source and MIT‑licensed.
• Download for macOS, Linux, or Windows (released yesterday).
• Install via Homebrew:

brew install --cask emdash

Call for Feedback

We’d love to hear how your coding‑agent development setup looks, especially when working with multiple agents. Your feedback will help us improve Emdash.

Check out the repository:

We’ll be around in the comments — thanks!