workspace/tools/n8n-orchestrator.py

#!/usr/bin/env python3
"""
n8n Workflow Orchestrator — Delegate API calls to n8n via webhooks.

The agent never touches external API credentials directly. Instead, it triggers
n8n workflows that hold the credentials securely.

Usage:
  python3 n8n-orchestrator.py list                     # List configured workflows
  python3 n8n-orchestrator.py trigger <workflow> [data] # Trigger a workflow
  python3 n8n-orchestrator.py add <name> <webhook_url>  # Register a workflow
  python3 n8n-orchestrator.py status                    # Check n8n health
  python3 n8n-orchestrator.py log                       # Show recent executions

Setup:
  1. Install n8n: npm install -g n8n  (or Docker)
  2. Create webhook-triggered workflows in n8n
  3. Register them here with 'add' command
  4. Agents trigger workflows without knowing API keys
"""

import json
import sys
import time
from datetime import datetime
from pathlib import Path
from urllib.request import urlopen, Request
from urllib.error import URLError, HTTPError

DATA_DIR = Path(__file__).parent.parent / "data" / "n8n-orchestrator"
DATA_DIR.mkdir(parents=True, exist_ok=True)
WORKFLOWS_FILE = DATA_DIR / "workflows.json"
LOG_FILE = DATA_DIR / "executions.jsonl"
CONFIG_FILE = DATA_DIR / "config.json"

DEFAULT_CONFIG = {
    "n8n_base_url": "http://localhost:5678",
    "timeout_seconds": 30,
}

# Pre-built workflow templates agents can use
WORKFLOW_TEMPLATES = {
    "send-email": {
        "description": "Send an email via configured SMTP",
        "expected_payload": {"to": "email", "subject": "string", "body": "string"},
    },
    "fetch-crypto-price": {
        "description": "Get current price for a crypto asset",
        "expected_payload": {"symbol": "BTC"},
    },
    "post-discord": {
        "description": "Post a message to a Discord channel",
        "expected_payload": {"channel": "channel-name", "message": "string"},
    },
    "google-sheets-append": {
        "description": "Append a row to a Google Sheet",
        "expected_payload": {"sheet_id": "string", "values": ["col1", "col2"]},
    },
    "telegram-notify": {
        "description": "Send a Telegram notification",
        "expected_payload": {"chat_id": "string", "message": "string"},
    },
}


def load_config():
    if CONFIG_FILE.exists():
        return json.loads(CONFIG_FILE.read_text())
    CONFIG_FILE.write_text(json.dumps(DEFAULT_CONFIG, indent=2))
    return DEFAULT_CONFIG


def load_workflows():
    if WORKFLOWS_FILE.exists():
        return json.loads(WORKFLOWS_FILE.read_text())
    return {}


def save_workflows(workflows):
    WORKFLOWS_FILE.write_text(json.dumps(workflows, indent=2))


def log_execution(workflow_name, payload, response, success, duration_ms):
    entry = {
        "ts": datetime.now().isoformat(),
        "workflow": workflow_name,
        "payload_keys": list(payload.keys()) if isinstance(payload, dict) else str(type(payload)),
        "success": success,
        "duration_ms": duration_ms,
        "response_preview": str(response)[:200] if response else None,
    }
    with open(LOG_FILE, "a") as f:
        f.write(json.dumps(entry) + "\n")


def trigger_workflow(name, payload=None):
    """Trigger an n8n workflow by name."""
    workflows = load_workflows()
    if name not in workflows:
        print(f"❌ Workflow '{name}' not found. Use 'list' to see available workflows.")
        return None
    
    wf = workflows[name]
    url = wf["webhook_url"]
    config = load_config()
    
    print(f"🔄 Triggering workflow: {name}")
    print(f"   URL: {url}")
    
    payload = payload or {}
    data = json.dumps(payload).encode('utf-8')
    req = Request(url, data=data, headers={
        'Content-Type': 'application/json',
        'User-Agent': 'n8n-orchestrator/1.0',
    })
    
    start = time.time()
    try:
        with urlopen(req, timeout=config.get("timeout_seconds", 30)) as resp:
            duration = int((time.time() - start) * 1000)
            body = resp.read().decode('utf-8')
            try:
                result = json.loads(body)
            except json.JSONDecodeError:
                result = body
            
            log_execution(name, payload, result, True, duration)
            print(f"✅ Success ({duration}ms)")
            print(f"   Response: {json.dumps(result, indent=2) if isinstance(result, dict) else result[:200]}")
            return result
            
    except (HTTPError, URLError) as e:
        duration = int((time.time() - start) * 1000)
        error_msg = str(e)
        log_execution(name, payload, error_msg, False, duration)
        print(f"❌ Failed ({duration}ms): {error_msg}")
        return None


def add_workflow(name, webhook_url, description=""):
    workflows = load_workflows()
    workflows[name] = {
        "webhook_url": webhook_url,
        "description": description,
        "added": datetime.now().isoformat(),
    }
    save_workflows(workflows)
    print(f"✅ Added workflow: {name} -> {webhook_url}")


def list_workflows():
    workflows = load_workflows()
    print(f"\n📋 Registered Workflows ({len(workflows)}):")
    print("=" * 50)
    if not workflows:
        print("  No workflows registered yet.")
        print("  Use: python3 n8n-orchestrator.py add <name> <webhook_url>")
    for name, wf in workflows.items():
        print(f"  🔗 {name}")
        print(f"     URL: {wf['webhook_url']}")
        if wf.get("description"):
            print(f"     Desc: {wf['description']}")
    
    print(f"\n📦 Available Templates:")
    for name, tmpl in WORKFLOW_TEMPLATES.items():
        print(f"  📝 {name}: {tmpl['description']}")
        print(f"     Payload: {json.dumps(tmpl['expected_payload'])}")


def check_n8n_status():
    config = load_config()
    base = config.get("n8n_base_url", "http://localhost:5678")
    print(f"🏥 Checking n8n at {base}...")
    try:
        req = Request(f"{base}/healthz", headers={'User-Agent': 'n8n-orchestrator/1.0'})
        with urlopen(req, timeout=5) as resp:
            print(f"✅ n8n is running (HTTP {resp.status})")
    except Exception as e:
        print(f"❌ n8n unreachable: {e}")
        print(f"   Start it with: n8n start  (or docker run -d -p 5678:5678 n8nio/n8n)")


def show_log(limit=20):
    if not LOG_FILE.exists():
        print("No executions logged yet.")
        return
    lines = LOG_FILE.read_text().strip().split('\n')
    print(f"\n📜 Recent Executions (last {limit}):")
    for line in lines[-limit:]:
        entry = json.loads(line)
        icon = "✅" if entry["success"] else "❌"
        print(f"  {icon} [{entry['ts'][:19]}] {entry['workflow']} ({entry['duration_ms']}ms)")


if __name__ == "__main__":
    args = sys.argv[1:]
    if not args or args[0] == "list":
        list_workflows()
    elif args[0] == "trigger" and len(args) >= 2:
        payload = json.loads(args[2]) if len(args) > 2 else {}
        trigger_workflow(args[1], payload)
    elif args[0] == "add" and len(args) >= 3:
        desc = args[3] if len(args) > 3 else ""
        add_workflow(args[1], args[2], desc)
    elif args[0] == "status":
        check_n8n_status()
    elif args[0] == "log":
        show_log()
    else:
        print(__doc__)