This guide gets you from download to your first agent task in about five minutes.

1. Download and install

Download Agentastic from agentastic.com/download.
Open the .dmg and drag Agentastic into your Applications folder.
Launch Agentastic. It runs as a background service with a menu bar icon and opens the Settings app on first run.

Apple Silicon and Intel Macs are both supported. macOS 14 (Sonoma) or later is recommended.

2. Grant permissions

Agentastic needs a few macOS permissions to work across your apps. The first-time setup will prompt you for each:

Accessibility: required to read selected text and to control the keyboard/mouse for computer-use tasks.
Screen Recording: required for screen capture and screenshot context.
Microphone: optional, for voice input and dictation.

You can review or change these any time in System Settings → Privacy & Security.

3. Connect a provider

Open Settings → Models and Providers. You have two ways to get a model:

Use the Agentastic provider: included with your plan, no API key needed. This is the fastest way to start.
Bring your own provider: add an Anthropic (sk-ant-…) or OpenAI (sk-…) API key, or sign in with your Claude or ChatGPT subscription via OAuth.

After saving credentials, click Test to verify the connection, then enable the provider. See Configuring Providers for details.

4. Open the launcher and run a prompt

Press ⌘ Return (the default shortcut) anywhere to open the launcher. Type a question and press Return:

Summarize the key points of the article in my active browser tab.

The response streams in place. Add /tab: to pick which browser tab to read, or /screen: to capture your screen.

5. Run your first agent task

Switch to agent mode so Agentastic can use tools. Type /agent (or press ⌘1) and give it a multi-step job:

/agent Find the three most-starred MCP server repos on GitHub this month
and save a short comparison to ~/Desktop/mcp-comparison.md

Agentastic plans the work, then asks for approval before each tool action (web search, writing a file). Approve the steps and watch it complete the task.

6. Customize

Change the hotkey, theme, and behavior in Settings → Preferences (see Settings).
Install a skill so the agent handles your recurring workflows (see Skills).
Connect messaging to reach your agent from Slack or iMessage (see Gateway).

Next steps

Core Concepts: the mental model behind Agentastic
Launcher Modes: chat, agent, vision, search, imagine, and more
Troubleshooting: if something isn't working

Pro tip: Start in chat mode for quick questions, and reach for /agent when you want Agentastic to do something rather than just answer.

Install & Setup