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Webhook Plugins Configuration

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Jm Rohmer edited this page Jul 11, 2026 · 1 revision

Webhook Plugins Configuration

After a successful build_site call, the Hugo MCP server can automatically trigger up to three post-build plugins: Cloudflare cache purge, IndexNow submission, and Google Indexing API notification. All three are opt-in — if the relevant config section is absent or empty, the plugin is silently skipped. Failures in any plugin are logged as warnings and do not affect the build response.

This page covers how to provision credentials for each plugin, configure them in /etc/mcp-hugo-server-go/config.yaml, and harden the setup for production.

Security Requirements

These rules apply to all three plugins. Read before proceeding.

  • Never commit secrets to git. api_token, key, and the Google SA JSON must exist only in the host config file or on the server filesystem.
  • Lock down the config file so only the service user can read it: 
    chmod 600 /etc/mcp-hugo-server-go/config.yaml
  • Apply the same permission to the Google service account JSON: 
    chmod 600 /etc/mcp-hugo-server-go/google-sa.json

Full Config Reference

# /etc/mcp-hugo-server-go/config.yaml

cloudflare:
  zone_id: YOUR_ZONE_ID          # CF dashboard › Overview › Zone ID (right sidebar)
  api_token: YOUR_TOKEN          # CF token with Zone / Cache Purge / Purge permission

indexnow:
  key: YOUR_KEY                  # 32–128 char hex key you generate
  key_location: https://www.example.com/YOUR_KEY.txt   # public URL to key verification file
  host: www.example.com          # your site hostname
  endpoint: https://api.indexnow.org/indexnow           # optional; this is the default

google_indexing:
  service_account_path: /etc/mcp-hugo-server-go/google-sa.json
  daily_quota_limit: 180         # Google allows 200/day; 180 gives a safety margin
  quota_state_path: /var/lib/mcp-hugo-server-go/google-index-quota.json

Omit any section you do not need. Each plugin checks for the presence of its own section independently.

Plugin 1: Cloudflare Cache Purge

Purges the full zone cache via Cloudflare API v4 after every successful build. Also fires on delete_page (single-URL purge).

Provision

  1. Log in to the Cloudflare dashboard → My Profile → API Tokens → Create Token.
  2. Use the Cache Purge template, or create a custom token with:
    • Permission: Zone / Cache Purge / Purge
    • Zone resources: scoped to your site's zone
  3. Copy the generated token — it is shown only once.
  4. Find your Zone ID on the dashboard Overview page (right sidebar under the domain name).

Configure

cloudflare:
  zone_id: "abc123def456..."
  api_token: "your-cloudflare-api-token"

Plugin 2: IndexNow

Submits all content page URLs to IndexNow (api.indexnow.org) after every successful build. Taxonomy and search pages (/tags/, /categories/, /authors/, /search/) are automatically filtered out.

Provision

  1. Generate a random hex key (32–128 characters): 
    openssl rand -hex 32
  2. Save the key as a plain-text file in your Hugo site's static/ directory, using the key value as the filename: 
    echo "YOUR_KEY" > static/YOUR_KEY.txt
  3. Build and deploy your site so the file is publicly accessible at the URL you will put in key_location. Verify with: 
    curl https://www.example.com/YOUR_KEY.txt
  4. The response body must be exactly the key string (no extra whitespace).

Configure

indexnow:
  key: "YOUR_KEY"
  key_location: "https://www.example.com/YOUR_KEY.txt"
  host: "www.example.com"
  # endpoint is optional; defaults to https://api.indexnow.org/indexnow

Plugin 3: Google Indexing API

Sends a URL_UPDATED notification to the Google Indexing API v3 for each content URL after a successful build, using service-account JWT authentication. Taxonomy and search pages are automatically filtered out.

Google's free tier allows 200 URL notifications per day. The server tracks daily usage in a state file and stops submitting once daily_quota_limit is reached.

Provision

  1. Verify site ownership in Google Search Console.

  2. In Google Cloud Console, create or select a project and enable the Web Search Indexing API:

    • Navigate to APIs & Services → Library → search for "Web Search Indexing API" → Enable.

  3. Create a service account:

    • IAM & Admin → Service Accounts → Create Service Account.
    • Grant it no project-level IAM roles (access is granted via Search Console, not Cloud IAM).
    • After creation, go to the service account → Keys → Add Key → JSON.
    • Download the JSON key file.

  4. Copy the JSON key to the server:

    scp google-sa.json user@yourserver:/etc/mcp-hugo-server-go/google-sa.json
chmod 600 /etc/mcp-hugo-server-go/google-sa.json

  5. Grant the service account access in Search Console:

    • Go to Search Console → Settings → Users and permissions → Add user.
    • Enter the service account email (e.g. my-sa@my-project.iam.gserviceaccount.com).
    • Set the role to Owner (required by the Indexing API).

  6. Create the quota state directory and ensure it is writable by the service user:

    mkdir -p /var/lib/mcp-hugo-server-go
chown mcp-hugo-server-go:mcp-hugo-server-go /var/lib/mcp-hugo-server-go

Configure

google_indexing:
  service_account_path: "/etc/mcp-hugo-server-go/google-sa.json"
  daily_quota_limit: 180
  quota_state_path: "/var/lib/mcp-hugo-server-go/google-index-quota.json"

Systemd Sandboxing

If the service unit uses ReadWritePaths (recommended), ensure the quota state directory and site directories are listed:

[Service]
ReadWritePaths=/var/lib/mcp-hugo-server-go /home/jm/hugo-site/content /home/jm/hugo-site/public

Without this, the server cannot write the quota state file and will log permission errors on every build.

If the Google SA JSON is in a directory owned by a different group (e.g. hugo-mcp), add the service user to that group:

usermod -aG hugo-mcp mcp-hugo-server-go
systemctl restart mcp-hugo-server-go

Plugin Behavior Summary

Plugin Trigger Filtered URLs Failure effect
Cloudflare Cache Purge build_site (full zone), delete_page (single URL) None Warning logged; build succeeds
IndexNow build_site Taxonomy + search pages Warning logged; build succeeds
Google Indexing API build_site Taxonomy + search pages Warning logged; build succeeds

All three plugins fire in sequence. No plugin failure blocks the others or the build response.

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