Monitor API Responses, Detect Changes, and Trigger Workflows
Monitor REST APIs and HTTP endpoints on a schedule, process JSON responses with visual workflows, and trigger actions when the data you care about changes—without maintaining a custom polling service.
- ✓Create a Monitor for an API (or receive a Webhook)
- ✓Build a Handler for the JSON response
- ✓Notify on Telegram or call another API when data changes
No credit card required. Read the docs
More Than an API Uptime Check
Check values inside the response, remember the previous run, and act only when something meaningful changed.
Partner API status change
Status API → extract status → compare with stored value → Telegram only when it changes
- 1Monitor fetches
status = operationaland the Handler stores it - 2Later run returns
status = degraded - 3Handler compares with Storage, sends Telegram, and saves the new state
Same pattern works for new records (lastProcessedTime), thresholds, and other JSON fields—not only status strings.
This is the kind of check that often starts as a cron script, then grows to include authentication, JSON parsing, state, conditions, notifications, API calls, logging, and hosting. NotifyWhenEvent keeps that logic in a managed Monitor + Handler workflow.
How NotifyWhenEvent Works
The same path as in the app: Source → Handler → Action and execution history.
Connect a Source
Create a Monitor to poll an API on a schedule, or a Webhook to receive inbound data. Attach that Source to the Handler that should process it.
Build a Handler
Attach the Monitor to a Handler—the visual pipeline that processes each response. Add steps to select fields, filter data, apply conditions, and use stored values from previous runs.
Act and review the run
Send a Telegram notification through a Channel, call another HTTP API, or do both. Use the Dashboard to review executions and verify what happened.
A Monitor starts the run. Its Handler processes the response, Storage keeps values between runs, and a Channel delivers notifications. Follow the quickstart guide →
What you can do
Four building blocks behind the status-change example—and most other API data workflows.
Monitor API & JSON response data
Schedule HTTP requests to REST APIs and HTTP endpoints, then work with the response body—not just the status code.
Learn how HTTP monitoring works →Process data with visual workflows
Filter, select, aggregate, convert, and transform API or webhook payloads in a Handler—without maintaining a custom script.
See how handlers and steps work →Keep state and detect changes
Remember values between runs and react when a field changes or when new records appear since the last check.
See how handlers use storage →Act with Telegram or API Call
Send a Telegram notification, call another HTTP API, or do both when your conditions are met.
Learn how API Call steps work →What Can You Monitor and Automate?
Reuse the same Monitor, Handler, Storage, and Action building blocks for different jobs.
New API records
API → records newer than lastProcessedTime → process → update stored state
Process only what is new since the last successful run.
Price or metric threshold
API → select a value → condition → Telegram or API Call
Act when a number crosses a limit you define in the workflow.
Webhook processing
Webhook → filter → transform → API Call and/or Telegram
Receive an HTTP callback and continue only when the payload matches.
Third-party API data
External API → inspect JSON → act when important fields change
Watch response data from APIs you do not control, without hosting a poller.
Who NotifyWhenEvent is for
Built for API/JSON data workflows—not every kind of monitoring.
A good fit if you
- ✓Developers and technical founders who poll APIs and care about values inside JSON responses
- ✓Teams that want visual workflows instead of maintaining another small polling service
- ✓Anyone who needs change-aware alerts or a downstream API call when data changes
Not the right tool if you need
- –Browser-based website change detection or full-stack observability
- –Uptime-only checks where the response data does not matter
FAQ
Common questions about API response monitoring with NotifyWhenEvent.
What is API response monitoring?+
API response monitoring means checking what an HTTP endpoint returns over time—especially values inside a JSON body—and acting when that data matters. NotifyWhenEvent combines scheduled Monitors (or Webhooks) with visual Handlers so you can process the response, keep state, and trigger actions.
How is NotifyWhenEvent different from an uptime monitor?+
An uptime monitor typically asks whether the endpoint is reachable and returns HTTP 200. NotifyWhenEvent is built to inspect response data, filter and transform it, compare with previous runs, and then notify on Telegram or call another API when your conditions are met.
Can NotifyWhenEvent monitor values inside a JSON response?+
Yes. In a Handler you can select fields, filter arrays, aggregate values, convert types, and branch on conditions using the data returned by the API.
Can I compare API data with a previous run?+
Yes. Handlers can read and write stored values between runs, so you can notify on status transitions or process only records newer than a saved timestamp.
Can NotifyWhenEvent process incoming webhooks?+
Yes. Create a Webhook source, attach a Handler, and process the payload through the same visual steps you use for Monitors.
Can a workflow call another API?+
Yes. The API Call step sends an outbound HTTP request during a run and stores the response for later conditions or notifications.
Can I send API alerts to Telegram?+
Yes. Telegram is the primary notification channel. Configure a Telegram channel, then add a Notification step in your Handler.
Do I need to write code?+
No custom polling service is required for common flows. You configure Monitors, Channels, and visual Handler steps in the app. Templates let you insert response fields into notifications and API calls.
More detail is in theproduct FAQanddocumentation.
Plans & Pricing (Beta)
Right now only the Free plan is available. Paid plans are coming soon — pricing and limits may change during beta.
Free
Free plan for getting started
- ✓Up to 3 monitored resources
- ✓Up to 6 handlers
- ✓Up to 2 notification channels
- ✓Up to 2 webhook sources
- ✓Up to 64 KB per webhook payload
- ✓10 requests / 60s per webhook
No credit card required · Telegram is the primary alert channel
Have questions? Contact us →Start monitoring the API data that matters
Connect a source, build a visual workflow, and act only when your conditions are met.