n8n JSON Health Check Workflow: Slack Alerts for HTTPS Failures

Keep your HTTPS JSON endpoints healthy — with Slack alerts for failures and recoveries

This n8n workflow checks an HTTPS JSON endpoint every hour, validates the HTTP status and JSON business rules, deduplicates repeated issues using n8n static data, and posts clear Slack alerts only when action is needed.

What this workflow does

• Runs hourly (or manually): Triggers every hour to monitor your target HTTPS JSON GET endpoint.
• Loads monitor configuration: Reads settings such as the target URL, expected HTTP status code, Slack channel ID, reminder interval, and up to four JSON field checks.
• Validates and structures checks: Verifies configuration and converts check rows into structured assertions.
• Performs the HTTPS check: Sends an HTTP GET request, captures the response status code and full JSON body.
• Evaluates health: Compares results against the expected status and business-rule assertions:
  • equals
  • nonEmpty
  • minItems
  • freshWithinMinutes
• Detects changes and deduplicates alerts: Uses n8n static workflow data to determine new failures, changed failures, reminder-worthy ongoing failures, or recoveries.
• Slack alerts only when needed: Posts a formatted message to Slack when an alert should fire; otherwise it completes silently.

Use cases

• Monitor a SaaS API health endpoint and alert your team when HTTPS or JSON expectations break.
• Detect data-quality regressions (empty fields, missing items, stale records) in JSON responses.
• Provide rapid recovery notifications when an endpoint returns to the expected HTTP status and JSON rules.

Technical details

• n8n nodes: if, set, code, no op, slack, sticky note
• HTTP Request authentication: Set in the HTTP Request node if your endpoint requires it (e.g., Header Auth like Authorization bearer token or X-API-Key).
• Deduplication logic: Relies on n8n static workflow data to avoid repeated Slack spam.
• Alert routing: Uses the configured Slack channel ID for failure/reminder/recovery messaging.