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Monitoring Redocly with Vigilmon: Developer Portal, API Reference, Workflows API & SSL Certificate Alerts

How to monitor Redocly API documentation platform with Vigilmon — developer portal availability, API reference page uptime, Redocly Workflows API, and SSL certificate monitoring.

Redocly is the API documentation platform that turns OpenAPI specifications into beautiful, interactive developer portals. Teams use Redocly to publish API references, manage multiple API versions, and host developer-facing documentation on custom domains. When your Redocly developer portal goes down, developers cannot look up endpoints, authentication requirements, or request/response schemas — stalling integrations and support requests. When an API reference page returns a 404 after a portal rebuild, partner developers hit dead links in their bookmarks and issue trackers. When the SSL certificate on your documentation domain expires, browsers block access with a security warning before anyone can read a single endpoint. Vigilmon gives you external visibility into every layer of your Redocly deployment: portal availability, individual API reference pages, the Redocly Workflows API, and SSL certificate expiry.

What You'll Build

  • A monitor on your Redocly developer portal home page to detect portal unavailability
  • HTTP monitors on critical API reference pages to catch 404s after portal rebuilds
  • A monitor on the Redocly Workflows API (if using Redocly.com hosted workflows)
  • SSL certificate monitoring for your documentation domain
  • An alerting setup that distinguishes portal-wide outages from individual page failures

Prerequisites

  • A Redocly developer portal deployed to a custom domain (e.g., docs.example.com) or hosted at *.redoc.ly / Redocly.com
  • At least one published API reference (OpenAPI 3.x or Swagger 2.0)
  • A free account at vigilmon.online

Step 1: Understand Redocly Availability Failure Modes

Redocly portals and API references can fail in several patterns:

Pattern 1 — Portal CDN or hosting unavailability: Redocly.com-hosted portals are served via CDN. If the CDN edge or origin is experiencing degradation, the portal returns 5xx errors or connection timeouts. Self-hosted Redocly portals (using @redocly/portal) fail when the hosting platform (Vercel, Netlify, AWS Amplify, or your own server) is unreachable.

Pattern 2 — Portal rebuild breaks specific pages: When you push a new OpenAPI spec, Redocly rebuilds the portal. If the new spec has errors or if a path was renamed or deleted, previously-working API reference URLs return 404. Partner developers following old links hit dead pages.

Pattern 3 — Custom domain DNS misconfiguration: Redocly portals are often served from a custom CNAME (e.g., docs.example.com → your-portal.redoc.ly). A DNS change or expiry of the CNAME record results in DNS resolution failure — the domain resolves to nothing, or to a Redocly default "portal not found" page.

Pattern 4 — SSL certificate expiry on custom domain: Custom domains on Redocly require SSL certificate management — either automatic (via Redocly's certificate provisioning or the hosting platform's Let's Encrypt integration) or manual. When the certificate expires, browsers display a security warning and block access without a click-through.

Pattern 5 — Redocly Workflows API unavailability: Teams using Redocly Workflows for automated linting, bundling, and publishing in CI/CD pipelines depend on the Redocly.com API. When the API is unavailable, redocly push and redocly lint commands in CI fail, blocking documentation updates.

Step 2: Monitor the Redocly Developer Portal Home Page

The portal home page is the entry point for all developers using your API documentation. Monitoring it confirms the CDN, DNS, and hosting stack are all functioning:

curl https://docs.example.com
# Returns HTML with your portal title and navigation
  1. Log in to Vigilmon → Add Monitor → HTTP.
  2. URL: https://docs.example.com (your portal domain).
  3. Check interval: 5 minutes.
  4. Response timeout: 15 seconds.
  5. Expected status: 200.
  6. Keyword: A distinctive string from your portal title (e.g., API Documentation, your company name, or your product name).
  7. Label: Redocly portal home.
  8. Click Save.

Redocly.com hosted portals: If your portal is at https://yourcompany.redoc.ly rather than a custom domain, use that URL. You'll still want SSL monitoring on the .redoc.ly subdomain if you have one, as certificate issues can affect subdomain certificate chains.

Alert sensitivity: 1 consecutive failure for a portal home page outage — your entire developer audience is affected immediately.

Step 3: Monitor Critical API Reference Pages

Individual API reference pages can break after a portal rebuild even when the home page remains accessible. A renamed API path, a deleted tag group, or a spec validation error can make specific endpoint pages return 404 while the portal index appears healthy:

# Monitor your most important API reference page
curl https://docs.example.com/api-reference/authentication
# Returns HTML with your authentication documentation

# Monitor a specific versioned API reference
curl https://docs.example.com/v2/reference
# Returns HTML with v2 API reference content
  1. Add Monitor → HTTP.
  2. URL: https://docs.example.com/api-reference/authentication.
  3. Check interval: 10 minutes.
  4. Response timeout: 15 seconds.
  5. Expected status: 200.
  6. Keyword: authentication or a key term from that page's content.
  7. Label: API reference — authentication page.
  8. Click Save.

Repeat for each critical API reference page (typically 2–4 pages covering authentication, core endpoints, and the API index):

| Page | Why monitor it | |---|---| | /api-reference | Main API reference index — all developers land here | | /api-reference/authentication | Auth docs — most-read page for new integrators | | /changelog | Version history — checked during API upgrades | | /v2/reference | Version-specific reference — fails when version is removed from spec |

Keyword selection: Choose a keyword that is unique to the page content, not just the portal chrome. For an authentication page, Bearer token or API key is better than Documentation, which appears on every page.

Step 4: Monitor the Redocly Workflows API

If your team uses Redocly Workflows for CI/CD-integrated documentation publishing (redocly push, redocly lint, redocly bundle), the Redocly.com API is a dependency of your documentation deployment pipeline:

# Check Redocly API availability
curl https://app.redocly.com
# Returns 200 with Redocly app content
  1. Add Monitor → HTTP.
  2. URL: https://app.redocly.com.
  3. Check interval: 5 minutes.
  4. Response timeout: 15 seconds.
  5. Expected status: 200.
  6. Keyword: Redocly.
  7. Label: Redocly Workflows app.
  8. Click Save.

CI/CD impact: When app.redocly.com is unavailable, your CI pipeline's redocly push step will fail, but the currently-published portal remains available to developers. This monitor helps you distinguish "Redocly publishing pipeline is down" from "developer portal is down" — two very different urgencies.

Step 5: Monitor SSL Certificates on Your Documentation Domain

A lapsed SSL certificate on your documentation domain triggers browser security warnings that prevent developers from accessing any page without clicking through a warning — effectively taking your developer portal offline:

openssl s_client -connect docs.example.com:443 2>/dev/null | openssl x509 -noout -dates
# notAfter=Jan 15 00:00:00 2027 GMT
  1. Add Monitor → SSL Certificate.
  2. Domain: docs.example.com.
  3. Alert when expiry is within: 30 days.
  4. Alert again: 14 days, 7 days, 3 days, 1 day.
  5. Click Save.

If you have multiple documentation domains (e.g., docs.example.com for production and docs-staging.example.com for staging), add an SSL monitor for each:

openssl s_client -connect docs-staging.example.com:443 2>/dev/null | openssl x509 -noout -dates

Redocly custom domain certificates: Redocly provisions SSL certificates for custom domains using Let's Encrypt or their CDN provider's certificate system. Auto-renewal can fail if the DNS CNAME is removed, if a CAA record blocks Let's Encrypt, or if the domain registrar fails to renew the domain itself. A 30-day alert gives you time to investigate before the certificate actually expires.

Step 6: Configure Alerting

In Vigilmon under Settings → Notifications, configure alert channels for your documentation team and on-call rotation:

| Monitor | Trigger | Action | |---|---|---| | Portal home page | Non-200 or keyword missing | Check CDN status; verify DNS resolution; inspect hosting platform status | | API reference pages | 404 or keyword missing | Portal rebuild broke a page; check recent OpenAPI spec changes; verify route paths in redocly.yaml | | Redocly Workflows API | Non-200 or keyword missing | Redocly.com incident; CI documentation publishing blocked; portal content unchanged | | SSL certificate | < 30 days to expiry | Renew certificate; check Redocly custom domain SSL settings or Let's Encrypt renewal logs |

Escalation path for portal outages:

  • Portal home 404/5xx: Check hosting platform status (Vercel, Netlify, AWS Amplify) and Redocly status at status.redocly.com.
  • Individual page 404: Inspect redocly.yaml for route changes; check the latest OpenAPI spec push for removed paths.
  • Keyword missing but 200 returned: Portal is up but content changed — check if a portal rebuild replaced expected content.
  • SSL expiry alert: Go to your Redocly portal settings → Custom Domains → SSL status; or check the hosting platform's certificate management.

Common Redocly Failure Modes and What Vigilmon Catches

| Scenario | Vigilmon monitor | |---|---| | CDN outage affecting Redocly-hosted portals | Portal home page 5xx; all monitors fire | | OpenAPI spec push deletes a path — page 404s | Home page green; specific reference page monitor fires | | DNS CNAME removed — portal domain resolves nowhere | All page monitors fail (DNS error) | | SSL certificate auto-renewal fails | SSL monitor fires 30 days before; browsers show security warning | | Redocly.com API down — redocly push fails in CI | Workflows API monitor fires; portal stays live for readers | | Portal rebuild introduces broken links in navigation | Reference page monitors catch specific 404s | | Hosting platform (Vercel/Netlify) incident | Portal home page 5xx; all monitors fire simultaneously | | Wrong OpenAPI spec version published — 404 on versioned paths | Version-specific page monitor fires; home page stays green | | Custom domain certificate chain misconfigured | SSL monitor fires; browsers reject certificate | | Rate limiting on Redocly CDN during traffic spike | Portal pages time out; response timeout alert fires |

Your Redocly developer portal is the first thing partner developers and API consumers see when they start integrating with your platform. When it's down or broken, they cannot build. Vigilmon monitors every layer: the portal home page availability, individual critical API reference pages that break after rebuilds, the Redocly Workflows publishing API your CI/CD pipeline depends on, and the SSL certificates protecting your documentation domain — so you know the moment something breaks and can restore developer access before integrators notice they are blocked.

Start monitoring your Redocly developer portal in under 5 minutes — register free at vigilmon.online.

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