--- sidebar_position: 11 title: "Automate Anything with Cron" description: "Real-world automation patterns using Hermes cron — monitoring, reports, pipelines, and multi-skill workflows" --- # Automate Anything with Cron The [daily briefing bot tutorial](/docs/guides/daily-briefing-bot) covers the basics. This guide goes further — five real-world automation patterns you can adapt for your own workflows. For the full feature reference, see [Scheduled Tasks (Cron)](/docs/user-guide/features/cron). :::info Key Concept Cron jobs run in fresh agent sessions with no memory of your current chat. Prompts must be **completely self-contained** — include everything the agent needs to know. ::: --- ## Pattern 1: Website Change Monitor Watch a URL for changes and get notified only when something is different. The `script` parameter is the secret weapon here. A Python script runs before each execution, and its stdout becomes context for the agent. The script handles the mechanical work (fetching, diffing); the agent handles the reasoning (is this change interesting?). Create the monitoring script: ```bash mkdir -p ~/.hermes/scripts ``` ```python title="~/.hermes/scripts/watch-site.py" import hashlib, json, os, urllib.request URL = "https://example.com/pricing" STATE_FILE = os.path.expanduser("~/.hermes/scripts/.watch-site-state.json") # Fetch current content req = urllib.request.Request(URL, headers={"User-Agent": "Hermes-Monitor/1.0"}) content = urllib.request.urlopen(req, timeout=30).read().decode() current_hash = hashlib.sha256(content.encode()).hexdigest() # Load previous state prev_hash = None if os.path.exists(STATE_FILE): with open(STATE_FILE) as f: prev_hash = json.load(f).get("hash") # Save current state with open(STATE_FILE, "w") as f: json.dump({"hash": current_hash, "url": URL}, f) # Output for the agent if prev_hash and prev_hash != current_hash: print(f"CHANGE DETECTED on {URL}") print(f"Previous hash: {prev_hash}") print(f"Current hash: {current_hash}") print(f"\nCurrent content (first 2000 chars):\n{content[:2000]}") else: print("NO_CHANGE") ``` Set up the cron job: ```bash /cron add "every 1h" "If the script output says CHANGE DETECTED, summarize what changed on the page and why it might matter. If it says NO_CHANGE, respond with just [SILENT]." --script ~/.hermes/scripts/watch-site.py --name "Pricing monitor" --deliver telegram ``` :::tip The [SILENT] Trick When the agent's final response contains `[SILENT]`, delivery is suppressed. This means you only get notified when something actually happens — no spam on quiet hours. ::: --- ## Pattern 2: Weekly Report Compile information from multiple sources into a formatted summary. This runs once a week and delivers to your home channel. ```bash /cron add "0 9 * * 1" "Generate a weekly report covering: 1. Search the web for the top 5 AI news stories from the past week 2. Search GitHub for trending repositories in the 'machine-learning' topic 3. Check Hacker News for the most discussed AI/ML posts Format as a clean summary with sections for each source. Include links. Keep it under 500 words — highlight only what matters." --name "Weekly AI digest" --deliver telegram ``` From the CLI: ```bash hermes cron create "0 9 * * 1" \ "Generate a weekly report covering the top AI news, trending ML GitHub repos, and most-discussed HN posts. Format with sections, include links, keep under 500 words." \ --name "Weekly AI digest" \ --deliver telegram ``` The `0 9 * * 1` is a standard cron expression: 9:00 AM every Monday. --- ## Pattern 3: GitHub Repository Watcher Monitor a repository for new issues, PRs, or releases. ```bash /cron add "every 6h" "Check the GitHub repository NousResearch/hermes-agent for: - New issues opened in the last 6 hours - New PRs opened or merged in the last 6 hours - Any new releases Use the terminal to run gh commands: gh issue list --repo NousResearch/hermes-agent --state open --json number,title,author,createdAt --limit 10 gh pr list --repo NousResearch/hermes-agent --state all --json number,title,author,createdAt,mergedAt --limit 10 Filter to only items from the last 6 hours. If nothing new, respond with [SILENT]. Otherwise, provide a concise summary of the activity." --name "Repo watcher" --deliver discord ``` :::warning Self-Contained Prompts Notice how the prompt includes the exact `gh` commands. The cron agent has no memory of previous runs or your preferences — spell everything out. ::: --- ## Pattern 4: Data Collection Pipeline Scrape data at regular intervals, save to files, and detect trends over time. This pattern combines a script (for collection) with the agent (for analysis). ```python title="~/.hermes/scripts/collect-prices.py" import json, os, urllib.request from datetime import datetime DATA_DIR = os.path.expanduser("~/.hermes/data/prices") os.makedirs(DATA_DIR, exist_ok=True) # Fetch current data (example: crypto prices) url = "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin,ethereum&vs_currencies=usd" data = json.loads(urllib.request.urlopen(url, timeout=30).read()) # Append to history file entry = {"timestamp": datetime.now().isoformat(), "prices": data} history_file = os.path.join(DATA_DIR, "history.jsonl") with open(history_file, "a") as f: f.write(json.dumps(entry) + "\n") # Load recent history for analysis lines = open(history_file).readlines() recent = [json.loads(l) for l in lines[-24:]] # Last 24 data points # Output for the agent print(f"Current: BTC=${data['bitcoin']['usd']}, ETH=${data['ethereum']['usd']}") print(f"Data points collected: {len(lines)} total, showing last {len(recent)}") print(f"\nRecent history:") for r in recent[-6:]: print(f" {r['timestamp']}: BTC=${r['prices']['bitcoin']['usd']}, ETH=${r['prices']['ethereum']['usd']}") ``` ```bash /cron add "every 1h" "Analyze the price data from the script output. Report: 1. Current prices 2. Trend direction over the last 6 data points (up/down/flat) 3. Any notable movements (>5% change) If prices are flat and nothing notable, respond with [SILENT]. If there's a significant move, explain what happened." \ --script ~/.hermes/scripts/collect-prices.py \ --name "Price tracker" \ --deliver telegram ``` The script does the mechanical collection; the agent adds the reasoning layer. --- ## Pattern 5: Multi-Skill Workflow Chain skills together for complex scheduled tasks. Skills are loaded in order before the prompt executes. ```bash # Use the arxiv skill to find papers, then the obsidian skill to save notes /cron add "0 8 * * *" "Search arXiv for the 3 most interesting papers on 'language model reasoning' from the past day. For each paper, create an Obsidian note with the title, authors, abstract summary, and key contribution." \ --skill arxiv \ --skill obsidian \ --name "Paper digest" ``` From the tool directly: ```python cronjob( action="create", skills=["arxiv", "obsidian"], prompt="Search arXiv for papers on 'language model reasoning' from the past day. Save the top 3 as Obsidian notes.", schedule="0 8 * * *", name="Paper digest", deliver="local" ) ``` Skills are loaded in order — `arxiv` first (teaches the agent how to search papers), then `obsidian` (teaches how to write notes). The prompt ties them together. --- ## Managing Your Jobs ```bash # List all active jobs /cron list # Trigger a job immediately (for testing) /cron run # Pause a job without deleting it /cron pause # Edit a running job's schedule or prompt /cron edit --schedule "every 4h" /cron edit --prompt "Updated task description" # Add or remove skills from an existing job /cron edit --skill arxiv --skill obsidian /cron edit --clear-skills # Remove a job permanently /cron remove ``` --- ## Delivery Targets The `--deliver` flag controls where results go: | Target | Example | Use case | |--------|---------|----------| | `origin` | `--deliver origin` | Same chat that created the job (default) | | `local` | `--deliver local` | Save to local file only | | `telegram` | `--deliver telegram` | Your Telegram home channel | | `discord` | `--deliver discord` | Your Discord home channel | | `slack` | `--deliver slack` | Your Slack home channel | | Specific chat | `--deliver telegram:-1001234567890` | A specific Telegram group | | Threaded | `--deliver telegram:-1001234567890:17585` | A specific Telegram topic thread | --- ## Tips **Make prompts self-contained.** The agent in a cron job has no memory of your conversations. Include URLs, repo names, format preferences, and delivery instructions directly in the prompt. **Use `[SILENT]` liberally.** For monitoring jobs, always include instructions like "if nothing changed, respond with `[SILENT]`." This prevents notification noise. **Use scripts for data collection.** The `script` parameter lets a Python script handle the boring parts (HTTP requests, file I/O, state tracking). The agent only sees the script's stdout and applies reasoning to it. This is cheaper and more reliable than having the agent do the fetching itself. **Test with `/cron run`.** Before waiting for the schedule to trigger, use `/cron run ` to execute immediately and verify the output looks right. **Schedule expressions.** Supported formats: relative delays (`30m`), intervals (`every 2h`), standard cron expressions (`0 9 * * *`), and ISO timestamps (`2025-06-15T09:00:00`). Natural language like `daily at 9am` is not supported — use `0 9 * * *` instead. --- *For the complete cron reference — all parameters, edge cases, and internals — see [Scheduled Tasks (Cron)](/docs/user-guide/features/cron).*