Code Execution

Run Python, JavaScript, shell commands, and other code in a secure sandboxed environment

Overview

Kortix agents execute code in isolated Daytona sandbox environments. Each project gets its own dedicated sandbox with a full Linux environment, enabling agents to run scripts, process data, interact with APIs, and build applications safely.

The sandbox provides a complete development environment with pre-installed tools, persistent storage in /workspace, and automatic resource management.

Sandbox Architecture

From the source code (sandbox.py:1-145):

from daytona_sdk import AsyncDaytona, DaytonaConfig, CreateSandboxFromSnapshotParams

daytona_config = DaytonaConfig(
    api_key=config.DAYTONA_API_KEY,
    api_url=config.DAYTONA_SERVER_URL, 
    target=config.DAYTONA_TARGET,
)

daytona = AsyncDaytona(daytona_config)

Sandbox Lifecycle

Sandboxes are created from snapshots with pre-configured services:

async def create_sandbox(password: str, project_id: str = None) -> AsyncSandbox:
    """Create a new sandbox with all required services configured and running."""
    
    params = CreateSandboxFromSnapshotParams(
        snapshot=Configuration.SANDBOX_SNAPSHOT_NAME,
        public=True,
        labels={'id': project_id} if project_id else None,
        env_vars={
            "CHROME_PERSISTENT_SESSION": "true",
            "RESOLUTION": "1048x768x24",
            "VNC_PASSWORD": password,
            "CHROME_DEBUGGING_PORT": "9222",
        },
        auto_stop_interval=15,    # Stop after 15 min idle
        auto_archive_interval=30,  # Archive after 30 min
    )
    
    sandbox = await daytona.create(params)
    return sandbox

State Management

From sandbox.py:34-66:

async def get_or_start_sandbox(sandbox_id: str) -> AsyncSandbox:
    """Retrieve a sandbox by ID, check its state, and start it if needed."""
    
    sandbox = await daytona.get(sandbox_id)
    
    # Check if sandbox needs to be started
    if sandbox.state in [SandboxState.ARCHIVED, SandboxState.STOPPED, SandboxState.ARCHIVING]:
        logger.info(f"Sandbox is in {sandbox.state} state. Starting...")
        await daytona.start(sandbox)
        
        # Wait for sandbox to reach STARTED state
        for _ in range(30):
            await asyncio.sleep(1)
            sandbox = await daytona.get(sandbox_id)
            if sandbox.state == SandboxState.STARTED:
                break
        
        # Start supervisord when restarting
        await start_supervisord_session(sandbox)
    
    return sandbox

Sandbox Tool Base

All tools inherit from SandboxToolsBase (tool_base.py:13-84):

class SandboxToolsBase(Tool):
    def __init__(self, project_id: str, thread_manager: Optional['ThreadManager'] = None):
        super().__init__()
        self.project_id = project_id
        self.thread_manager = thread_manager
        self.workspace_path = "/workspace"
        self._sandbox_info: Optional[SandboxInfo] = None

    async def _ensure_sandbox(self) -> AsyncSandbox:
        """Ensure sandbox is initialized and ready."""
        if self._sandbox_info is None:
            sandbox_info = await resolve_sandbox(
                project_id=self.project_id,
                account_id=account_id,
                db_client=client,
                require_started=True
            )
            self._sandbox_info = sandbox_info
        return self._sandbox_info.sandbox

Code Execution Methods

Command Execution

Agents can run shell commands using the Bash tool:

# Run Python script
result = await sandbox.process.exec(
    "python script.py",
    timeout=120
)

# Run with environment variables
result = await sandbox.process.exec(
    "npm run build",
    env={"NODE_ENV": "production"},
    timeout=300
)

Working Directory

All code executes with /workspace as the persistent working directory:

@property
def workspace_path(self) -> str:
    return "/workspace"

def clean_path(self, path: str) -> str:
    """Clean and normalize paths relative to /workspace"""
    return clean_path(path, self.workspace_path)

Session Management

Long-running services use supervisord:

async def start_supervisord_session(sandbox: AsyncSandbox):
    """Start supervisord in a session."""
    session_id = "supervisord-session"
    try:
        await sandbox.process.create_session(session_id)
        await sandbox.process.execute_session_command(
            session_id,
            SessionExecuteRequest(
                command="exec /usr/bin/supervisord -n -c /etc/supervisor/conf.d/supervisord.conf",
                var_async=True
            )
        )
    except Exception as e:
        logger.warning(f"Could not start supervisord: {str(e)}")

Real-World Examples

Example 1: Python Data Processing

# Create Python script
create_file(
    file_path="process_data.py",
    file_contents="""
import pandas as pd
import json

# Load data
df = pd.read_csv('/workspace/data.csv')

# Process
results = df.groupby('category').agg({
    'value': ['sum', 'mean', 'count']
}).to_dict()

# Save results
with open('/workspace/results.json', 'w') as f:
    json.dump(results, f, indent=2)

print('Processing complete')
"""
)

# Execute script
result = bash("python /workspace/process_data.py")

# Read results
results = read_file("results.json")

Example 2: API Integration

# Create API client script
create_file(
    file_path="fetch_data.py",
    file_contents="""
import requests
import os

api_key = os.getenv('API_KEY')
response = requests.get(
    'https://api.example.com/data',
    headers={'Authorization': f'Bearer {api_key}'}
)

with open('/workspace/api_response.json', 'w') as f:
    f.write(response.text)
"""
)

# Run with environment variables
bash(
    "python /workspace/fetch_data.py",
    env={"API_KEY": "secret_key"}
)

Example 3: Build Process

# Install dependencies
bash("cd /workspace && npm install")

# Run build
bash(
    "cd /workspace && npm run build",
    env={"NODE_ENV": "production"},
    timeout=300
)

# Check build output
files = bash("ls -lh /workspace/dist")

Example 4: Multi-Language Processing

# JavaScript processing
bash("node /workspace/transform.js")

# Python analysis  
bash("python /workspace/analyze.py")

# Shell script orchestration
bash("bash /workspace/pipeline.sh")

Pre-installed Tools

Sandboxes come with common development tools:

• Languages: Python 3.11+, Node.js, Bash
• Package Managers: pip, npm, apt
• Version Control: git
• Utilities: curl, wget, jq, zip/unzip
• Process Management: supervisord
• Browser: Chromium (for browser automation)

File System Access

From tool_base.py:56-84:

@property
def sandbox(self) -> AsyncSandbox:
    """Access the sandbox instance."""
    if self._sandbox_info is None:
        raise RuntimeError("Sandbox not initialized. Call _ensure_sandbox() first.")
    return self._sandbox_info.sandbox

@property
def sandbox_url(self) -> str:
    """Get public URL for the sandbox."""
    if self._sandbox_info is None:
        raise RuntimeError("Sandbox URL not initialized.")
    return self._sandbox_info.sandbox_url or ""

File operations through the sandbox SDK:

# Read file
content = await sandbox.fs.download_file("/workspace/file.txt")

# Write file
await sandbox.fs.upload_file(
    content.encode(),
    "/workspace/output.txt"
)

# Create directory
await sandbox.fs.create_folder("/workspace/data", "755")

# Get file info
file_info = await sandbox.fs.get_file_info("/workspace/file.txt")
print(f"Size: {file_info.size}, Modified: {file_info.mod_time}")

Network Access

Sandboxes have full internet access:

# Install packages
bash("pip install requests pandas numpy")

# Clone repositories
bash("git clone https://github.com/user/repo.git /workspace/repo")

# Download files
bash("curl -o /workspace/data.json https://api.example.com/data")

# API calls
bash("curl -X POST https://api.example.com/endpoint -d @/workspace/payload.json")

Resource Limits

Sandboxes have resource constraints:

resources=Resources(
    cpu=2,      # 2 CPU cores
    memory=4,   # 4 GB RAM
    disk=5,     # 5 GB disk
)

Auto-Stop and Archiving

From sandbox.py:115-117:

auto_stop_interval=15,    # Stop after 15 minutes of inactivity
auto_archive_interval=30,  # Archive after 30 minutes stopped

• Auto-Stop: Sandbox stops after 15 minutes of no activity to save resources
• Auto-Archive: Stopped sandboxes archive after 30 minutes
• Resume: Archived sandboxes automatically restart when accessed

Security Features

Isolation

• Each project gets dedicated sandbox
• No cross-project access
• Isolated network namespace
• Separate file systems

Environment Variables

Secure credential handling:

# Pass secrets via environment variables
result = await sandbox.process.exec(
    "python script.py",
    env={
        "DATABASE_URL": "postgresql://...",
        "API_KEY": "secret_key"
    }
)

Cleanup

async def delete_sandbox(sandbox_id: str) -> bool:
    """Delete a sandbox by its ID."""
    sandbox = await daytona.get(sandbox_id)
    await daytona.delete(sandbox)
    return True

Best Practices

1. Use Workspace Path

# ✅ GOOD: Use /workspace for persistence
bash("python /workspace/script.py")

# ❌ BAD: Temp directories may be cleared
bash("python /tmp/script.py")

2. Handle Timeouts

# Set appropriate timeout for long operations
bash(
    "npm run build",
    timeout=300  # 5 minutes
)

3. Check Exit Codes

result = bash("python script.py")
if result.exit_code != 0:
    logger.error(f"Script failed: {result.stderr}")

4. Install Dependencies Once

# Create requirements.txt
create_file(
    file_path="requirements.txt",
    file_contents="pandas\nrequests\nnumpy"
)

# Install once
bash("pip install -r /workspace/requirements.txt")

# Packages persist across sessions

Port Exposure

Sandboxes can expose services:

# Port 8080 is auto-exposed for web previews
preview_url = await sandbox.get_preview_link(8080)
print(f"Preview: {preview_url.url}")

HTTP servers on port 8080 are automatically accessible via public URL.

Monitoring and Debugging

# Check sandbox state
sandbox = await daytona.get(sandbox_id)
print(f"State: {sandbox.state}")

# View process output
result = bash("ps aux")
print(result.stdout)

# Check disk usage
disk = bash("df -h /workspace")

Configuration

Sandbox execution requires:

DAYTONA_API_KEY=your_api_key
DAYTONA_SERVER_URL=https://api.daytona.io
DAYTONA_TARGET=your_target

Limitations

• Command timeout: Default 120 seconds (configurable)
• No root access (runs as unprivileged user)
• No systemd (use supervisord instead)
• Limited GPU access
• Auto-stops after inactivity