1. Opening Problem Statement
Emma, a content manager for a busy eco-mobility blog, spends hours each week manually summarizing new WordPress posts to engage readers quickly. The constant edits and updates lead to errors and inconsistencies, wasting at least 5 hours weekly and delaying publication. Beyond wasted time, her team loses reader attention due to lack of concise summaries at the top of posts, impacting traffic and user experience negatively.
This workflow addresses Emma’s challenge by automating AI-generated summaries, ensuring each new WordPress post has a neat, well-structured summary at the top without requiring manual intervention or extra WordPress plugins that might slow down the site.
2. What This Automation Does
When triggered, this workflow:
- Fetches new or selected WordPress posts in edit mode to work on raw content.
- Converts post HTML content into Markdown for better AI processing.
- Classifies whether a post already contains an AI summary, preventing duplicate summaries.
- Generates a clean, bullet-point AI summary using OpenAI’s GPT-4o-mini model with a customized prompt tailored for electric mobility content.
- Updates the WordPress post by inserting the AI summary block at the top without altering existing excerpts.
- Logs summarized posts into Google Sheets for tracking and uses Slack to notify the marketing team about new summaries.
The benefits include: Saving several hours a week managing content summaries, reducing manual errors, and keeping the site lightweight by avoiding bulky WordPress plugins.
3. Prerequisites ⚙️
- n8n account (self-hosting optional via platforms like Hostinger)
- WordPress website with REST API access & permission to edit posts
- Google Sheets with service account credentials to log summarized posts
- OpenAI API key (for GPT-4o-mini model)
- Slack workspace with OAuth2 setup for notification channel
4. Step-by-Step Guide
Step 1: Choose Your Trigger
Navigate to the When clicking ‘Test workflow’ node to run manually for testing. For production, enable either:
- Schedule Trigger: Runs at set intervals (e.g., every 5 minutes) to check for new posts.
- Webhook Trigger: Fires immediately when a new post is published on WordPress (requires webhook setup and authentication).
Enabling triggers involves clicking the node, then toggling the “Disabled” switch off to activate.
Common mistake: Forgetting to disable the manual trigger before production causes confusion.
Step 2: Retrieve WordPress Posts
Depending on the trigger:
- Schedule Trigger: The Date & Time – Subtract node subtracts the schedule interval (e.g., 30 seconds) to fetch posts published after the last run using WordPress – Get Last Posts.
- Manual/webhook: The workflow uses WordPress – Get All Posts or WordPress – Get Post by ID nodes to fetch targeted posts.
This step’s output includes the raw post content necessary for processing.
Common mistake: Not setting “context=edit” prevents retrieving raw content editable by the workflow.
Step 3: Convert HTML to Markdown
The HTML to Markdown node converts WordPress HTML content into Markdown so the AI understands formatting better. Navigate to this node and check the “html” parameter to ensure it uses the raw content property ({{$json.content.rendered}}).
Common mistake: Feeding HTML from the wrong property reduces summary quality.
Step 4: Check for Existing AI Summaries
The workflow cross-references the post ID with rows in Google Sheets – Get rows, filtering by post_id to see if the post already has an AI summary to avoid duplication.
Then it uses Text Classifier (langchain.textClassifier) to analyze the Markdown text and classify the post as summarized or not_summarized.
Common mistake: Not matching column names between Google Sheets and the workflow causes false negatives.
Step 5: Generate AI Summary Using OpenAI
If the post isn’t summarized, the Markdown content goes to the OpenAI node configured to use GPT-4o-mini with a custom system prompt. The prompt instructs the model to output an HTML block with bullet points summarizing the post—perfect for WordPress blocks.
The preset prompt focuses on electric mobility but can be customized to your website’s topic.
Common mistake: Failing to update the system prompt for your content domain reduces summary relevance.
Step 6: Update WordPress Post with AI Summary
The summary HTML output is combined with the existing post content and posted back to WordPress by the WordPress – Update Post HTTP Request node that authenticates via the WordPress API.
This node preserves the original excerpt and injects the summary at the top of the post content.
Common mistake: Not correctly setting the WordPress API credentials leads to update failures.
Step 7: Log Summary in Google Sheets
The Google Sheets – Add Row node logs important data like the post ID, AI summary, post link, edit link, and the date the summary was generated.
This enables tracking of processed posts and avoids repeated processing.
Step 8: Notify the Team via Slack
The Slack – Notify Channel node sends a formatted message to a designated channel, alerting the team about the new AI summary including links to view and edit the post.
Common mistake: Sending notifications without proper Slack OAuth2 scopes causes failure.
Step 9: Final Tweaks and Testing
Review your Slack messages, Google Sheets entries, and WordPress posts for proper summary insertion. Test multiple posts to ensure no duplicates or missing summaries.
5. Customizations ✏️
- Change AI Prompt for Different Content Domains
In the OpenAI node, modify the system prompt to fit your blog’s niche (e.g., “sustainable urban mobility,” “technology news,” etc.). This improves summary relevance. - Adjust Summary Styling
You can edit the HTML block’s CSS styles inside the system prompt in the OpenAI node to better match your WordPress theme’s colors and fonts. - Add More Post Metadata
In the Set fields – Prepare data for Gsheets & Slack node, add fields such as author name, post categories, or tags to log and notify additional context. - Switch Between Triggers
Disable the manual trigger and enable either the webhook or scheduled trigger based on your publishing workflow. - Extend Slack Notifications
Add more details or post stats in the Slack message or post to multiple channels for wider reach.
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6. Troubleshooting 🔧
Problem: “WordPress post update fails with 401 Unauthorized.”
Cause: Incorrect or missing API credentials.
Solution: Verify WordPress API credentials are correctly added under credentials and that the API user has sufficient permissions.
Problem: “No AI summary detected or duplicate summaries added.”
Cause: Mismatch between Google Sheets data and actual post content leading to false classification.
Solution: Ensure Google Sheets column names exactly match workflow field names, and the Text Classifier is set up with correct input paths.
Problem: “Slack notifications not sending.”
Cause: Insufficient Slack OAuth2 scopes or incorrect channel ID.
Solution: Re-authenticate Slack node with proper scopes, check the channel ID, and test with simple message payload.
7. Pre-Production Checklist ✅
- Confirm OpenAI API key is active and has enough quota.
- Verify WordPress API credentials and test GET/POST operations manually.
- Ensure Google Sheets template is copied exactly with correct column names.
- Test Slack integration with test messages before enabling automation.
- Run workflow manually first to verify correct summary generation and insertion.
- Backup your WordPress site before enabling updates in production.
8. Deployment Guide
Activate your chosen trigger node by disabling manual triggers and enabling either the Schedule Trigger or the Webhook Trigger. Monitor the workflow’s executions in n8n dashboard for errors or missed posts.
Regularly check Google Sheets logs and Slack notifications to ensure continuous operation. Adjust schedule intervals or webhook setup as necessary based on content volume.
9. FAQs
Q: Can I use a different AI model instead of GPT-4o-mini?
A: Yes, the workflow supports other OpenAI GPT models. Just update the modelId in the OpenAI node.
Q: Does this consume many OpenAI API credits?
A: API usage depends on post length and frequency, so controlling the number of posts processed helps manage costs.
Q: Is my data safe?
A: All data processing happens within your n8n instance and APIs. Use secure credentials and HTTPS to protect data in transit.
Q: Can this handle high volumes of posts?
A: Yes, but adjust Schedule Trigger frequency and batching accordingly to prevent rate limits.
10. Conclusion
You just set up a powerful automation that extracts valuable AI-generated summaries for your WordPress posts using n8n, OpenAI, Google Sheets, and Slack integration. This workflow streamlines content management by eliminating manual summary writing and reducing errors, saving you hours each week and improving reader engagement.
Next, consider automating social media promotion of summarized posts or further enriching content with related links and tags automatically. This is a practical, scalable system designed to grow with your content needs.
Happy automating! 🎯 (Stay focused on your unique content while AI handles the summary.)