Harnesses

Agent-native apps run with an AI agent alongside the app UI. Locally, the agent panel is embedded directly in your app. In the cloud, Builder.io provides a managed harness with collaboration and visual editing.

Embedded Agent Panel

  • Ships with @agent-native/core — no separate package needed
  • Agent panel embedded directly in your app with chat and optional CLI terminal
  • Supports multiple AI coding CLIs — switch between them from the settings panel
  • Toggle between production mode (app tools only) and development mode (full filesystem, shell, and database access)
  • Great for local development, self-hosted production, and OSS

Supported CLIs

CLICommandKey Flags
Claude Codeclaude--dangerously-skip-permissions, --resume, --verbose
Codexcodex--full-auto, --quiet
Gemini CLIgemini--sandbox
OpenCodeopencode
Builder.iobuilder

Switch between CLIs at any time from the agent panel settings. The terminal restarts with the selected CLI.

Builder.io Cloud Harness

  • Runs in the cloud
  • Real-time collaboration — multiple users can watch/interact simultaneously
  • Visual editing, roles and permissions
  • Parallel agent execution for faster iteration
  • Great for team use

How It Works

The framework provides type-safe APIs so you never deal with raw messaging:

  1. Agent chat — use sendToAgentChat() to send messages to the agent
  2. Generation state — use useAgentChatGenerating() to track when the agent is running
  3. File watching — SSE endpoint keeps UI in sync when the agent modifies files
  4. Script systempnpm script <name> dispatches to callable scripts

Your app code is identical regardless of how the agent is provided.