API response monitoring

Your API is up.
Is the response right?

A 200 OK can still hide an empty result or a broken service. Send the request your app makes, check the JSON fields that matter, and get alerted when the response is wrong.

Explore examples

Free tier available · No credit card required

Service healthIllustrative monitor
GETapi.example.com/v1/health
200 OK184 msResponse check failed
{
  "status": "ok",
  "services": {
    "database": "down"
  }
}
statusequalsok
services.databaseexpectedup· got down

An HTTP success. A failed response check.
Catch the problem your status code missed.

Inside the setup

Your request. Your rules.
A response you can trust.

Choose an example to see exactly what you configure and what Sentinelboard checks. Then switch to a failing response to see what it catches.

Make sure your API and its database are healthy, even when the endpoint returns 200 OK.

API response monitorIllustrative setup · Demo data

01 Configure the request

URL & HTTP method
GEThttps://api.example.com/v1/health
Headers
AuthorizationBearer demo_api_key

02 Add expected response checks

Use dot notation to reach nested JSON fields, such as services.database.

  • statusEquals"ok"
  • services.databaseEquals"up"

03 Test and inspect the result

200 OKExample JSON response
{
  "status": "ok",
  "services": {
    "database": "up"
  }
}

All checks passed

status · Passed

Returned "ok"

services.database · Passed

Returned "up"

The response matches both rules. In the setup flow, use Test Request to verify your endpoint before continuing.
Once saved: checked every 5 minutesFailed checks can trigger your configured alerts

Four ways to define a healthy response

Equals

Match an expected value.

status = "ok"

Contains

Look for text within a value.

data.query contains "coffee"

Exists

Check that a field is present and not null.

data.user.id exists

Not Empty

Reject null, empty strings, arrays, or objects.

data.products is not empty

Everything you need for API monitoring

Go beyond status codes. Validate responses, track performance, and get alerted when something breaks.

Response body validation

Don't just check status codes — verify the response contains the data you expect. Catch silent failures that return 200 OK with wrong data.

HTTP method support

Monitor GET, POST, PUT, PATCH, and DELETE endpoints. Add headers for authentication and send JSON bodies with POST, PUT, or PATCH requests.

Response time tracking

Track response times over time and set thresholds. Get alerted when an endpoint degrades before it becomes a user-facing problem.

Multi-channel alerts

Get notified via email, Slack, Telegram, or webhooks. Your choice, your workflow.

Status code validation

Catch HTTP 4xx and 5xx errors, connection failures, and failed response checks. See the status code alongside the results for each JSON field.

5-minute check intervals

Your API endpoints are checked every 5 minutes so you catch issues quickly without overwhelming your services.

Get API failure alerts where you work

Receive API failure notifications on the channels you already use. No new apps to install — just the right alert at the right time.

  • Email
  • Slack
  • Telegram
  • Webhooks

You know what can break. Now keep an eye on it.

Replace your uptime pinger, error tracker, and cron monitor with one tool. Free to start, no credit card needed.

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First monitor live in under a minute · Free tier included