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HTTP monitors check web endpoints by making HTTP requests and evaluating the response against your assertions. They’re the most feature-rich monitor type, supporting custom headers, request bodies, TLS verification, authentication, and 11 assertion types.
Define this in code. Manage HTTP monitors in your monitoring-as-code workflow: YAML format · Terraform · CI/CD patterns

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When to use HTTP monitors

  • Health check endpoints — verify /health or /status returns 200
  • API availability — check that key API endpoints respond within latency budgets
  • Website uptime — confirm marketing pages, app frontends, and landing pages load
  • SSL certificate expiry — get alerts before certificates expire using the ssl_expiry assertion
  • Content validation — verify response bodies contain expected data using body_contains, json_path, or regex
  • Redirect chains — track redirect behavior with redirect_count and redirect_target assertions

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How it works

  1. DevHelm sends an HTTP request from each configured probe region at the set frequency
  2. The response is evaluated against all configured assertions
  3. Each assertion records pass/fail with the configured severity (fail or warn)
  4. If any fail-severity assertion fails, the check is marked as failed
  5. Failed checks flow into the incident policy engine

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Supported methods

MethodTypical use
GETHealth checks, page monitoring, API reads
POSTAPI endpoint testing with request bodies
PUTAPI update endpoint testing
PATCHPartial update endpoint testing
DELETEDeletion endpoint testing
HEADLightweight availability checks (no response body)

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Quick example

devhelm monitors create \
  --name "API Health" \
  --type HTTP \
  --url https://api.example.com/health \
  --method GET \
  --frequency 60 \
  --regions us-east,eu-west

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Next steps

Configuration

Every HTTP monitor field — URL, method, headers, body, TLS, auth.

Assertions

All 11 HTTP assertion types with examples.

First HTTP monitor

Step-by-step tutorial.

SSL monitoring

Monitor certificate expiration dates.