AutoCoder

A long-running autonomous coding agent powered by the Claude Agent SDK. This tool can build complete applications over multiple sessions using a two-agent pattern (initializer + coding agent). Includes a React-based UI for monitoring progress in real-time.

Video Tutorial

Watch the setup and usage guide →

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Prerequisites

Claude Code CLI (Required)

This project requires the Claude Code CLI to be installed. Install it using one of these methods:

macOS / Linux:

curl -fsSL https://claude.ai/install.sh | bash

Windows (PowerShell):

irm https://claude.ai/install.ps1 | iex

Authentication

You need one of the following:

• Claude Pro/Max Subscription - Use claude login to authenticate (recommended)
• Anthropic API Key - Pay-per-use from https://console.anthropic.com/

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Quick Start

Option 1: Web UI (Recommended)

Windows:

start_ui.bat

macOS / Linux:

./start_ui.sh

This launches the React-based web UI at http://localhost:5173 with:

• Project selection and creation
• Kanban board view of features
• Real-time agent output streaming
• Start/pause/stop controls

Option 2: CLI Mode

Windows:

start.bat

macOS / Linux:

./start.sh

The start script will:

1. Check if Claude CLI is installed
2. Check if you're authenticated (prompt to run claude login if not)
3. Create a Python virtual environment
4. Install dependencies
5. Launch the main menu

Creating or Continuing a Project

You'll see options to:

• Create new project - Start a fresh project with AI-assisted spec generation
• Continue existing project - Resume work on a previous project

For new projects, you can use the built-in /create-spec command to interactively create your app specification with Claude's help.

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How It Works

Two-Agent Pattern

1. Initializer Agent (First Session): Reads your app specification, creates features in a SQLite database (features.db), sets up the project structure, and initializes git.

2. Coding Agent (Subsequent Sessions): Picks up where the previous session left off, implements features one by one, and marks them as passing in the database.

Feature Management

Features are stored in SQLite via SQLAlchemy and managed through an MCP server that exposes tools to the agent:

• feature_get_stats - Progress statistics
• feature_get_next - Get highest-priority pending feature
• feature_get_for_regression - Random passing features for regression testing
• feature_mark_passing - Mark feature complete
• feature_skip - Move feature to end of queue
• feature_create_bulk - Initialize all features (used by initializer)

Session Management

• Each session runs with a fresh context window
• Progress is persisted via SQLite database and git commits
• The agent auto-continues between sessions (3 second delay)
• Press Ctrl+C to pause; run the start script again to resume

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Important Timing Expectations

Note: Building complete applications takes time!

• First session (initialization): The agent generates feature test cases. This takes several minutes and may appear to hang - this is normal.

• Subsequent sessions: Each coding iteration can take 5-15 minutes depending on complexity.

• Full app: Building all features typically requires many hours of total runtime across multiple sessions.

Tip: The feature count in the prompts determines scope. For faster demos, you can modify your app spec to target fewer features (e.g., 20-50 features for a quick demo).

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Project Structure

autonomous-coding/
├── start.bat                 # Windows CLI start script
├── start.sh                  # macOS/Linux CLI start script
├── start_ui.bat              # Windows Web UI start script
├── start_ui.sh               # macOS/Linux Web UI start script
├── start.py                  # CLI menu and project management
├── start_ui.py               # Web UI backend (FastAPI server launcher)
├── autonomous_agent_demo.py  # Agent entry point
├── agent.py                  # Agent session logic
├── client.py                 # Claude SDK client configuration
├── security.py               # Bash command allowlist and validation
├── progress.py               # Progress tracking utilities
├── prompts.py                # Prompt loading utilities
├── api/
│   └── database.py           # SQLAlchemy models (Feature table)
├── mcp_server/
│   └── feature_mcp.py        # MCP server for feature management tools
├── server/
│   ├── main.py               # FastAPI REST API server
│   ├── websocket.py          # WebSocket handler for real-time updates
│   ├── schemas.py            # Pydantic schemas
│   ├── routers/              # API route handlers
│   └── services/             # Business logic services
├── ui/                       # React frontend
│   ├── src/
│   │   ├── App.tsx           # Main app component
│   │   ├── hooks/            # React Query and WebSocket hooks
│   │   └── lib/              # API client and types
│   ├── package.json
│   └── vite.config.ts
├── .claude/
│   ├── commands/
│   │   └── create-spec.md    # /create-spec slash command
│   ├── skills/               # Claude Code skills
│   └── templates/            # Prompt templates
├── generations/              # Generated projects go here
├── requirements.txt          # Python dependencies
└── .env                      # Optional configuration (N8N webhook)

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Generated Project Structure

After the agent runs, your project directory will contain:

generations/my_project/
├── features.db               # SQLite database (feature test cases)
├── prompts/
│   ├── app_spec.txt          # Your app specification
│   ├── initializer_prompt.md # First session prompt
│   └── coding_prompt.md      # Continuation session prompt
├── init.sh                   # Environment setup script
├── claude-progress.txt       # Session progress notes
└── [application files]       # Generated application code

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Running the Generated Application

After the agent completes (or pauses), you can run the generated application:

cd generations/my_project

# Run the setup script created by the agent
./init.sh

# Or manually (typical for Node.js apps):
npm install
npm run dev

The application will typically be available at http://localhost:3000 or similar.

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Security Model

This project uses a defense-in-depth security approach (see security.py and client.py):

1. OS-level Sandbox: Bash commands run in an isolated environment
2. Filesystem Restrictions: File operations restricted to the project directory only
3. Bash Allowlist: Only specific commands are permitted:
   • File inspection: ls, cat, head, tail, wc, grep
   • Node.js: npm, node
   • Version control: git
   • Process management: ps, lsof, sleep, pkill (dev processes only)

Commands not in the allowlist are blocked by the security hook.

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Web UI Development

The React UI is located in the ui/ directory.

Development Mode

cd ui
npm install
npm run dev      # Development server with hot reload

Building for Production

cd ui
npm run build    # Builds to ui/dist/

Note: The start_ui.bat/start_ui.sh scripts serve the pre-built UI from ui/dist/. After making UI changes, run npm run build to see them when using the start scripts.

Tech Stack

• React 18 with TypeScript
• TanStack Query for data fetching
• Tailwind CSS v4 with neobrutalism design
• Radix UI components
• WebSocket for real-time updates

Real-time Updates

The UI receives live updates via WebSocket (/ws/projects/{project_name}):

• progress - Test pass counts
• agent_status - Running/paused/stopped/crashed
• log - Agent output lines (streamed from subprocess stdout)
• feature_update - Feature status changes

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Configuration (Optional)

N8N Webhook Integration

The agent can send progress notifications to an N8N webhook. Create a .env file:

# Optional: N8N webhook for progress notifications
PROGRESS_N8N_WEBHOOK_URL=https://your-n8n-instance.com/webhook/your-webhook-id

When test progress increases, the agent sends:

{
  "event": "test_progress",
  "passing": 45,
  "total": 200,
  "percentage": 22.5,
  "project": "my_project",
  "timestamp": "2025-01-15T14:30:00.000Z"
}

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Customization

Changing the Application

Use the /create-spec command when creating a new project, or manually edit the files in your project's prompts/ directory:

• app_spec.txt - Your application specification
• initializer_prompt.md - Controls feature generation

Modifying Allowed Commands

Edit security.py to add or remove commands from ALLOWED_COMMANDS.

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Troubleshooting

"Claude CLI not found" Install the Claude Code CLI using the instructions in the Prerequisites section.

"Not authenticated with Claude" Run claude login to authenticate. The start script will prompt you to do this automatically.

"Appears to hang on first run" This is normal. The initializer agent is generating detailed test cases, which takes significant time. Watch for [Tool: ...] output to confirm the agent is working.

"Command blocked by security hook" The agent tried to run a command not in the allowlist. This is the security system working as intended. If needed, add the command to ALLOWED_COMMANDS in security.py.

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License

This project is licensed under the GNU Affero General Public License v3.0 - see the LICENSE.md file for details. Copyright (C) 2026 Leon van Zyl (https://leonvanzyl.com)