Orca is a free, open-source Agent Development Environment (ADE) that lets you run multiple AI coding agents — Claude Code, Codex, Gemini, OpenCode, and 25+ others — in parallel, each isolated in its own git worktree, all from one desktop app. It does not replace your coding agents; it orchestrates them, so the bottleneck shifts from "waiting for one agent to finish" to "reviewing a fleet of finished diffs." And yes, with the right setup, the entire stack can cost you nothing beyond the hardware you already own.
Last verified: 2026-07-31
- Orca is free and open source under the MIT License (GitHub, official site).
- Runs 25+ CLI coding agents in parallel, each in an isolated git worktree.
- Desktop app for macOS, Windows, and Linux; mobile companion for iOS and Android.
- Orca does NOT provide AI models — you bring your own subscriptions or free API keys.
- Fully free path: Orca + a free agent CLI (e.g., OpenCode) + a free or freemium model API.
What is Orca and why does it matter for AI coding?
Orca is an Agent Development Environment built by Stably AI (a Y Combinator W22 company) that solves a specific bottleneck: AI coding agents are fast, but you can only run one at a time in a normal terminal. You fire off a prompt to Claude Code or Codex, wait ten minutes, review the output, then start the next task. The agent is fast, but you become the bottleneck. Orca fixes this by running a fleet of agents simultaneously, each in its own isolated git worktree, so they never step on each other's files or branches.
The project is TypeScript-based, MIT-licensed, and has grown from a few thousand GitHub stars in early 2026 to over 20,000 by late July 2026, frequently topping GitHub Trending (source: GitHub repository). The official site is onorca.dev, and the team states they "ship daily."
The key distinction: Orca is not a model. It is not another Claude or ChatGPT competitor. It is an orchestration layer — a full desktop environment (terminal, editor, browser preview, diff review, fleet manager) that wraps the coding agents you already use. You bring your own subscriptions and API keys; Orca provides the infrastructure to run them all at once.
How does Orca keep parallel agents from colliding?
Every task in Orca gets its own git worktree — a lightweight working directory that shares the same .git object database but has its own branch, files, and terminal session. This means three agents can edit the same repository simultaneously without merge conflicts, because each operates in a separate worktree on a separate branch. When an agent finishes, you review its diff, comment on specific lines if needed, and merge the winner.
Git worktrees are a native Git feature (not an Orca invention), but Orca makes them the core unit of task management. Creating and switching worktrees is far cheaper than running git checkout repeatedly, and because each worktree shares the .git object library, you never clone the full repository multiple times.
Which AI coding agents does Orca support?
Orca supports any CLI-based coding agent — if it runs in a terminal, it runs in Orca. The built-in list includes 25+ agents as of July 2026 (source: Orca README):
| Agent | Provider | Free option available? |
|---|---|---|
| Claude Code | Anthropic | No (subscription required) |
| Codex | OpenAI | No (subscription required) |
| OpenCode | Open source (SST) | Yes (free, BYOK) |
| Gemini CLI | Yes (free tier available) | |
| Cursor CLI | Cursor | No (subscription required) |
| GitHub Copilot | GitHub/Microsoft | No (subscription required) |
| Cline | Open source | Yes (BYOK) |
| Goose | Block | Yes (BYOK) |
| Grok | xAI | No (subscription required) |
| Kimi | Moonshot | Freemium |
The practical implication: if you already pay for Claude Code or Codex, you plug those subscriptions into Orca and run them in parallel at no extra cost. If you have no paid subscriptions, you can use a free agent CLI like OpenCode paired with a free or freemium model API.
How to set up Orca for free (step by step)
This is the fully free path — no paid agent subscriptions required. You will use Orca's free desktop app, a free open-source coding agent CLI, and a free-tier model API.
Step 1: Download and install Orca
Download the desktop app from onorca.dev or the GitHub releases page. It is available for:
- macOS (Apple Silicon and Intel)
- Windows
- Linux
The app is MIT-licensed and free with no feature gating. Install it like any other desktop application.
Step 2: Install a free coding agent CLI
Orca does not ship with its own models. You need at least one CLI coding agent installed and authenticated. For a fully free setup, use OpenCode — an open-source, MIT-licensed terminal coding agent from SST that supports BYOK (bring your own key) model providers:
# Install OpenCode
npm install -g opencode
# Or use the official installer
curl -fsSL https://opencode.ai/install | bash
OpenCode supports multiple model providers, including those with free tiers (Google Gemini, OpenRouter free models, local models via Ollama). Configure it with your preferred provider's API key.
Step 3: Add your project to Orca
Open the Orca desktop app and either:
- Click Browse Folder to open an existing local project, or
- Click Clone from URL to clone a GitHub repository, or
- Click Create New Project to start from scratch.
Orca detects the repository and sets up the git worktree infrastructure automatically.
Step 4: Launch parallel agents in separate worktrees
From the Orca interface, create a new worktree for each task:
# Using Orca's CLI
orca worktree create --base main --name fix-auth-bug
orca agent run --worktree fix-auth-bug --agent opencode --prompt "Fix the authentication bug in login.ts"
# Run a second agent in parallel on a different worktree
orca worktree create --base main --name add-health-endpoint
orca agent run --worktree add-health-endpoint --agent opencode --prompt "Add a /health endpoint to the API"
Each agent runs in its own isolated worktree with its own terminal session. They cannot conflict with each other. You can split terminal panes side by side to watch all of them work simultaneously.
Step 5: Preview and review
Orca includes an embedded Chromium browser for live preview. If you are building a web app, click the + button and open a new browser tab with your localhost URL to see the running app. You can:
- Select any UI element (click it) and send it as context to the agent with feedback
- Annotate the page — right-click any element, describe what the agent should change (e.g., "make the headline bright yellow"), choose whether it is a command or a question, and batch multiple annotations before sending them all at once
- Review diffs — when agents finish, Orca presents their changes side by side. Comment on any diff line and send those comments back to the agent for a revised attempt
This review-first loop is what makes parallel agents safe: you are not blindly merging code you have not inspected.
What is Design Mode and why is it useful?
Design Mode is Orca's built-in feature for visual feedback during agent coding. Instead of describing what you want changed in text — which is often ambiguous — you click the actual UI element in Orca's embedded browser and annotate it directly. You can queue up multiple changes (e.g., "fix this button color," "reword this headline," "center this section") and send them to the agent in one batch. The agent receives the HTML, CSS, and a screenshot of the selected element as context, which makes the feedback far more precise than a vague text prompt (source: Orca docs).
This is especially useful for non-technical team members or founders who can see what is wrong but may not know the exact CSS property or component name to fix it.
Can you monitor agents from your phone?
Yes. Orca ships a mobile companion app for iOS (via App Store or TestFlight) and Android (APK from the GitHub releases page). You can monitor your agent fleet, receive notifications when an agent finishes or needs input, and send follow-up prompts from your phone. This is useful for longer-running tasks — kick off a refactor, go about your day, and check on it from your phone.
Orca vs traditional IDEs: what is the difference?
| Capability | Orca | Traditional IDEs (VS Code, etc.) |
|---|---|---|
| Parallel agents, each in own worktree | Yes | No (one at a time) |
| Cross-platform (macOS, Windows, Linux) | Yes | Yes |
| Open source (MIT) | Yes | Varies |
| Terminal with splits + WebGL | Yes (Ghostty-class) | Partial (integrated terminal) |
| Embedded browser with Design Mode | Yes | No |
| Inline diff comments to agents | Yes | Limited |
| 25+ built-in agents | Yes | 1-2 via extensions |
| MCP, hooks, skills | Yes | Partial |
The core difference is architectural: traditional IDEs were built for one human typing into one editor. Extensions bolt AI on top. Orca was built from the ground up around the parallel-agent paradigm — the worktree is the unit of work, the agent is the worker, and you are the director.
Is Orca actually free, or are there hidden costs?
The Orca application itself is genuinely free — MIT-licensed, no feature gating, no premium tier, no middleman billing. You can download it, use it, and even modify the source code at no cost.
The potential cost is the AI models your agents call. Orca uses your own subscriptions and API keys, so you pay the model providers directly. The breakdown:
- Already subscribing to Claude Code, Codex, or Cursor? Plugging them into Orca costs nothing extra — you are already paying.
- No subscriptions? Use a free open-source CLI agent (OpenCode, Cline) with a free-tier model API. Google Gemini offers a free tier, OpenRouter provides free access to several open models, and you can run models locally with Ollama for zero ongoing cost.
- Running many agents in parallel? Each agent consumes its provider's API quota or subscription limits. Orca includes usage tracking and shows when rate limits reset, and the account switcher lets you hot-swap between multiple provider accounts to route around exhausted quotas.
What this means for you
If you are a developer, founder, or small team already using AI coding agents, Orca removes the single biggest productivity bottleneck: serial execution. Instead of waiting for one agent to finish before starting the next, you run a fleet and review results. The free, MIT-licensed app plus your existing subscriptions means there is no cost barrier to trying it.
If you have no paid subscriptions, the fully free path (Orca + OpenCode + a free-tier or local model) lets you experience parallel agentic coding at zero cost. Start with two or three concurrent tasks on a low-risk project, name your worktrees after the issue or hypothesis, and scale up only when the review workflow feels natural.
The honest caveat: Orca does not make any single agent smarter or faster. It multiplies throughput by removing scheduling overhead and idle waiting. If your workflow is one agent, one branch, one task at a time, worktree orchestration adds complexity without proportional benefit. The value emerges when you have multiple independent tasks that can genuinely run in parallel. If you are interested in a broader framework for managing AI agents like a team, see our guide on managing AI like a team rather than doing its job.
FAQ
Q: Is Orca completely free to use? A: Yes. The Orca desktop app is free and open source under the MIT License. There is no premium tier or feature gating. However, the AI coding agents it orchestrates may require their own subscriptions or API keys — Orca uses your existing accounts, it does not provide models.
Q: Do I need to pay for Claude Code or Codex to use Orca? A: No. While Orca works with paid agents like Claude Code and Codex, it also supports free open-source agent CLIs like OpenCode. You can pair a free agent with a free-tier model API (Google Gemini, OpenRouter free models, or local models via Ollama) for a completely free setup.
Q: How does Orca prevent agents from overwriting each other's work?
A: Each task runs in its own isolated git worktree — a separate working directory with its own branch, sharing the same underlying .git object database. Agents cannot step on each other's files or branches. You review and merge the results manually.
Q: Can I use Orca on Windows and Linux, or is it macOS only? A: Orca runs natively on macOS, Windows, and Linux. The desktop app is available from the official site or GitHub releases. A mobile companion app is available for iOS and Android for remote monitoring.
Q: How many agents can I run in parallel? A: There is no hard-coded limit in Orca. The practical limit is your system resources (each worktree and terminal consumes memory) and your model provider's rate limits. Orca includes usage tracking and an account switcher to help route around exhausted quotas. Most users start with 2-3 concurrent tasks and scale from there.
Q: What is the difference between Orca and a regular terminal multiplexer like tmux? A: A terminal multiplexer splits your screen but does not manage agents, worktrees, diffs, or reviews. Orca is a full development environment built around parallel agents — it handles worktree creation and isolation, agent assignment, live preview, diff annotation, and result aggregation. Think of it as an IDE purpose-built for agentic development, not just a terminal splitter.
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