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Watch any public URL and get notified when something changes. Class seats, price drops, blog posts, API data — Sift checks on a schedule and texts you the moment your condition is met.
Free users get up to 3 active monitors. Premium users get unlimited monitors.

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What You Can Ask

"Watch this page for open seats in CS 301"
"Alert me if Bitcoin drops below $60k"
"Monitor this RSS feed for new posts"
"Tell me when this API response changes"
"Show my monitors"
"Pause my seat watcher"

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How Monitors Work

Every monitor has three parts:
  1. Target — The URL to watch (webpage, API endpoint, or RSS feed)
  2. Condition — What change to look for (text changes, contains a keyword, number threshold, new entries)
  3. Alert — Where to send the notification (iMessage, email, push)
Sift polls the URL on a schedule (as often as every minute) and evaluates your condition against the latest content.

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Monitor Types

Webpage

Watch any public webpage. Optionally target a specific element with a CSS selector — like a seat count, price, or status field.

API

Poll a JSON API endpoint. Extract a specific value with a JSON path — like a price field, stock level, or status code.

RSS Feed

Watch an RSS or Atom feed for new entries. Get alerted when new posts, articles, or updates are published.

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Conditions

ConditionWhat it doesBest for
Text changesAlerts when page content changes at allGeneral monitoring
ContainsAlerts when content includes a keywordSeat availability, status changes
Not containsAlerts when a keyword disappearsSold-out detection
Number aboveAlerts when a value exceeds a thresholdStock prices, scores
Number belowAlerts when a value drops below a thresholdPrice drops, inventory
Number changesAlerts when any numeric value changesPrice tracking
New entryAlerts when a new RSS/Atom entry appearsBlog posts, news
JSON changesAlerts when API response data changesAPI monitoring

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Example Monitors

Type: Webpage · Condition: Contains “Open”Paste your university’s course registration page. Sift watches for open seats and texts you the moment one appears.
“Watch https://registrar.university.edu/course/CS301 for open seats”
Type: API · Condition: Number below thresholdTrack a product price via its API. Get alerted when it drops below your target.
“Alert me if this drops below $50”
Type: RSS · Condition: New entryFollow a professor’s blog, department news feed, or any RSS source. Sift texts you when new content is published.
“Watch this RSS feed and tell me when there’s a new post”
Type: API · Condition: JSON changesMonitor any public API endpoint for data changes — weather alerts, server status, sports scores, or anything with a JSON response.
“Tell me when this API response changes”
Type: Webpage · Condition: Text changesWatch a company’s careers page for new postings. Sift detects when the page content changes and alerts you.
“Watch this careers page and tell me when new jobs are posted”
Type: Webpage · Condition: Contains keywordWatch an event page, restaurant reservation system, or appointment scheduler for open slots.
“Watch this page for ‘available’ and text me when it shows up”

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Creating a Monitor

Describe what you want to watch in natural language: 
"Watch this registration page for open seats in CS 301"
"Monitor this page and alert me if the text changes"
"Watch this page for the word 'available'"

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Managing Monitors

ActionWhat to say
List”Show my monitors”
Pause”Pause my seat watcher”
Resume”Resume my price tracker”
Delete”Delete my blog monitor”

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Delivery Channels

Monitor alerts can be delivered via:
  • iMessage — Fastest for time-sensitive alerts like seat openings
  • Email — Good for less urgent updates
  • Push notification — Quick mobile alerts

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How It Differs from Automations

MonitorsAutomations
WatchesExternal URLsInternal Sift data
TriggerContent change on a webpage/API/feedSchedule, email, or event
Use case”Alert me when this page changes""Every morning, summarize my day”
Data sourceAny public URLYour calendar, tasks, email, Canvas

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Polling & Limits

  • Minimum interval: 1 minute
  • Maximum interval: 24 hours
  • Default interval: 5 minutes
  • Rate limiting: Sift respects robots.txt and limits requests to one per domain every 5 seconds
  • Auto-disable: Monitors that fail 10 times in a row are automatically paused
  • Notification cooldown: 30 minutes between repeat alerts for the same monitor (configurable)

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Tips

  • Use CSS selectors for precision — Instead of watching an entire page, target the specific element that matters (e.g., a seat count or price)
  • Start with longer intervals — 5-minute polling is fine for most use cases; save 1-minute polling for truly time-sensitive things
  • iMessage for urgency — Use iMessage delivery for monitors where speed matters (seat openings, price drops)
  • Set expiration dates — For temporary monitors (like class registration), set an expiry so they clean up automatically
  • Combine with automations — Use a monitor for external watching and an automation for internal follow-up actions