Using Mistral Vibe with Koyeb Sandboxes for Secure Code Execution

uv init mistral-vibe-in-sandbox

uv add koyeb-sdk

export KOYEB_API_TOKEN="your_koyeb_api_token_here" \
MISTRAL_API_KEY="your_mistral_api_key_here"

# mistral-vibe-in-sandbox/main.py

import os
import sys
import time
from koyeb import Sandbox

# mistral-vibe-in-sandbox/main.py
# ...
def main():
    """Main function to run Mistral Vibe inside a Koyeb Sandbox."""
    MISTRAL_API_KEY = os.getenv("MISTRAL_API_KEY")
    if not MISTRAL_API_KEY:
        print("Error: MISTRAL_API_KEY environment variable is not set")
        sys.exit(1)

# mistral-vibe-in-sandbox/main.py
# ...

    # Initialize sandbox
    print("=== Launching Koyeb Sandbox ===\n")
    sandbox = Sandbox.create(
        name="mistral-vibe-sandbox",
        wait_ready=True,
        idle_timeout=0,  # Keep sandbox alive indefinitely
        env={
            "MISTRAL_API_KEY": MISTRAL_API_KEY,
        }
    )
    print(f"✓ Sandbox created: {sandbox.name}\n")

# mistral-vibe-in-sandbox/main.py
# ...

    try:
        # Step 1: Clone the example-fastapi repository
        print("Step 1: Cloning example-fastapi repository...")
        result = sandbox.exec("cd /tmp && git clone https://github.com/koyeb/example-fastapi.git", on_stdout=lambda line: print(f"[Sandbox] {line}"), on_stderr=lambda line: print(f"[Sandbox ERROR] {line}"))
        if result.exit_code != 0:
            print(f"Error during repository cloning: {result.stderr}")
            return
        print("✓ Repository cloned\n")

# mistral-vibe-in-sandbox/main.py
# ...

        # Step 2: Install Python dependencies
        print("Step 2: Installing Python dependencies...")
        result = sandbox.exec("cd /tmp/example-fastapi && pip install -r requirements.txt", on_stdout=lambda line: print(f"[Sandbox] {line}"), on_stderr=lambda line: print(f"[Sandbox ERROR] {line}"), timeout=300)
        if result.exit_code != 0:
            print(f"Error during Python dependencies installation: {result.stderr}")
            return
        print("✓ Python dependencies installed\n")

# mistral-vibe-in-sandbox/main.py
# ...

        # Step 3: Use Mistral Vibe to enhance the app
        print("Step 3: Using Mistral Vibe to add a new query parameter 'name'...")
        prompt = f'''
I have a FastAPI application in tmp/example-fastapi/main.py

Please enhance it by adding a new query parameter called "name" to the root endpoint ("/") that allows users to input their name. The endpoint should return a personalized greeting message that includes the provided name. If no name is provided, it should default to "from Koyeb".

Provide only the updated main.py code in tmp/example-fastapi/main.py.
'''

        # Create a prompt file in the sandbox
        sandbox.filesystem.write_file("/tmp/vibe_prompt.txt", prompt)

        result = sandbox.exec(
            f"export PATH=\"$PATH:$HOME/.local/bin\" && PROMPT=\"$(cat /tmp/vibe_prompt.txt)\" && vibe --prompt \"$PROMPT\"",
            on_stdout=lambda line: print(f"[Sandbox] {line}"),
            on_stderr=lambda line: print(f"[Sandbox ERROR] {line}"),
            timeout=300,
        )
        if result.exit_code != 0:
            print(f"Error during Mistral Vibe suggestion: {result.stderr}")
            return
        vibe_response = result.stdout
        print(f"Received Mistral Vibe response:\n{vibe_response}\n")

# mistral-vibe-in-sandbox/main.py
# ...

        # Step 4: Start FastAPI application
        print("Step 4: Starting FastAPI application...")
        port = sandbox.expose_port(8000)
        process_id = sandbox.launch_process(
            "cd /tmp/example-fastapi && uvicorn main:app --host 0.0.0.0 --port 8000",
            cwd="/tmp",
        )
        domain = port.exposed_at
        print(f"✓ FastAPI started (process ID: {process_id})\n")

        # Wait for FastAPI to start
        time.sleep(3)

        print("✓ FastAPI is running on port 8000\n")
        print("📍 Your sandbox is now active with FastAPI running.\n")
        print(f"Access your application through your sandbox's public URL: {domain}?name=YourName\n")

# mistral-vibe-in-sandbox/main.py
# ...
        # Keep sandbox alive
        print("Sandbox is running. Press Ctrl+C to terminate.\n")
        try:
            while True:
                time.sleep(1)
        except KeyboardInterrupt:
            print("\n\nTerminating sandbox...")

# mistral-vibe-in-sandbox/main.py
# ...

    finally:
        # Clean up
        print("Cleaning up resources...")
        sandbox.delete()
        print("✓ Sandbox deleted")

if __name__ == "__main__":
    main()

uv run main.py

Access your application through your sandbox's public URL: https://YOUR-SANDBOX-ID.koyeb.app?name=YourName

fs = sandbox.filesystem

# Read a file from the sandbox
content = fs.read_file("/tmp/example-fastapi/main.py")
print(content)

# List directory contents
files = fs.list_dir("/tmp/example-fastapi")
print(files)

cat /tmp/example-fastapi/main.py

ls -la /tmp/example-fastapi