Multi-step request chains
Sequence multiple requests in one monitor — authenticate, create a resource, read it back, then verify it. Use any HTTP method (GET, POST, PUT, PATCH, DELETE, and more) with custom headers and JSON or raw bodies.
API Monitoring for Critical Endpoints
Go beyond 'is it up?'. NorthDuty runs synthetic API monitors on a schedule — chaining requests, authenticating, and asserting on status codes, JSON values, headers, and response time — so you catch broken endpoints before your users do.
Watch the endpoints your pages depend on, before a 500 breaks the UI.
Know your APIs work, not just that they respond
A 200 response doesn't mean your API is healthy. Login can succeed but return the wrong token, checkout can respond quickly with a malformed payload, and a third-party dependency can quietly start failing a single field. Uptime pings miss all of it.
NorthDuty API monitors run real request sequences against your endpoints on a schedule you choose. Each step can authenticate, send a body, and assert on exactly what the response should contain — so a passing check means the API actually works, end to end.
What you can build into an API monitor
Compose one or many steps per monitor, with assertions and chained data flowing between requests.
Assertions on every response
Validate status codes, JSONPath values, response headers, body content, and response time. Operators include equals, contains, exists, and numeric ranges — so a check fails the moment a payload drifts.
Variable extraction & chaining
Pull a token or ID out of one response with JSONPath and reuse it in later steps via {{variable}} placeholders — real authenticated flows, not isolated pings.
Built-in authentication
Attach Bearer tokens, Basic auth, or a custom API-key header per step — including credentials captured earlier in the same chain.
Plus: automatic API call tracking on every page check
Alongside synthetic API monitors, every NorthDuty health check still watches the API calls your pages actually make in a real browser — no code changes required.
XHR & Fetch interception
Each health check launches a real Chromium browser and intercepts the XHR and Fetch requests your page triggers, recording status codes, timing, and the service behind each call.
Classified and grouped by service
Failures are grouped by service and classified automatically: analytics and tracking are non-critical, while first-party APIs and payment providers are critical and weigh more on the health score.
Why teams run API monitors
Catch the failures that uptime checks and status codes alone never reveal.
- Verify that login, checkout, and payment APIs return correct data — not just a 200
- Catch breaking changes and bad deploys within minutes, on your own schedule
- Chain authenticated requests to exercise real end-to-end flows
- Assert on JSON fields, headers, and latency so silent regressions surface immediately
- Get a critical alert the moment a monitor fails, routed to every channel your team uses
How NorthDuty API monitoring works
Create a monitor, define its steps, and let NorthDuty run it on a schedule.
1
Define your steps
Add one or more requests to a monitor — set the method, URL, headers, body, and authentication. Reference your project base URL and chained values with {{...}} placeholders.
2
Add assertions
Tell each step what success looks like: an expected status code, a JSONPath value, a required header, body content, or a latency threshold.
3
Set a schedule
Choose how often the monitor runs — as frequently as every minute or as light as once a day — with a per-monitor timeout. Or trigger a run on demand.
4
Get alerted on failure
Every run is saved with per-step results, durations, and status codes. A failed run raises a critical API-monitor-failure alert to email, Slack, Teams, Discord, webhooks, Telegram, WhatsApp, or SMS.
Related NorthDuty Pages
Explore pricing, feature details, solution pages, and related tools connected to this website monitoring use case.
Pricing
Pricing
NorthDuty pricing for website monitoring: Free, $29 Starter, $79 Pro, $199 Business, and $499 Enterprise plans.
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Features
Explore NorthDuty features: website health checks every 5 minutes, screenshot-based visual change detection, and AI-suggested user journey monitoring in one project.
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Solutions
Explore NorthDuty solutions for ecommerce website monitoring, SaaS website monitoring, agency website monitoring, and startup website monitoring.
Browse SolutionsFeature
Uptime Monitoring
Monitor uptime every 5 minutes by default with HTTP, SSL, DNS, blank-page detection, broken resources, JavaScript errors, and API call tracking.
Explore Uptime MonitoringFeature
User Journey Monitoring
NorthDuty AI suggests 2-5 website journeys. Enable them in one click or describe a custom multi-step flow in plain text.
Explore User Journey MonitoringFeature
JavaScript Error Monitoring
NorthDuty detects JavaScript errors and console.error messages from a real browser on every health check — so front-end failures are visible before customers report them.
Explore JavaScript Error MonitoringFeature
Alerting
Send NorthDuty alerts to email, Slack, Teams, Discord, Google Chat, webhooks, Telegram, WhatsApp, and SMS.
Explore AlertingSolution
Ecommerce Website Monitoring
Use NorthDuty for ecommerce website monitoring to protect product pages, cart, checkout, payments, and revenue-critical customer journeys.
View Ecommerce Website MonitoringFrequently Asked Questions
Answers to common questions about this monitoring feature and when teams should use it.
How is API monitoring different from uptime monitoring?
Uptime monitoring tells you an endpoint responded. API monitoring verifies it responded correctly — asserting on status codes, JSON values, headers, and response time across one or more chained requests.
Can I chain requests and reuse data between them?
Yes. Extract values like auth tokens or IDs from a response with JSONPath and reference them in later steps using {{variable}} placeholders, so you can test authenticated, multi-step flows.
What can I assert on?
Status codes, JSONPath values in the response body, response headers, body content, and response time — with operators like equals, contains, exists, and numeric ranges.
How often do API monitors run, and what happens when one fails?
You set the frequency per monitor, from every minute up to once a day, plus an on-demand run. A failed run is saved with full per-step detail and triggers a critical API-monitor-failure alert to your connected channels.
Does NorthDuty still track the API calls my pages make?
Yes. Separately from synthetic API monitors, every health check intercepts the XHR and Fetch calls your pages make in a real browser, grouping failures by service and factoring critical ones into the health score.
Call To Action
Start monitoring your website with NorthDuty today.
Build a synthetic API monitor in minutes — chain requests, assert on real responses, and get alerted the moment an endpoint breaks.
Start on the free plan — add your base URL and monitoring starts in minutes.