1. Opening Problem Statement

Meet Joe, a content manager overwhelmed with managing a steady stream of PDF reports, whitepapers, and documents that need to be repurposed into engaging WordPress blog posts. Each manual conversion takes hours – extracting text, crafting SEO-friendly titles, formatting content, generating images, and coordinating approvals via email. The process is error-prone, inconsistent, and time-consuming, causing Joe to spend over 10 hours weekly just transforming PDFs into publishable content.

This manual effort also risks errors like missing key insights or poorly formatted blogs, potentially losing readers and damaging the site’s SEO performance. Joe needs an efficient, automated solution tailored specifically to convert PDFs into high-quality WordPress blog drafts, including a human review step to maintain content quality.

2. What This Automation Does

This n8n workflow revolutionizes Joe’s content creation by automating the entire pipeline from PDF upload to blog publishing with approval:

Automated PDF Upload & Text Extraction: Accepts PDF files via a web form trigger and extracts text precisely using the Extract Text node.
AI-Generated SEO Blog Post: Converts raw PDF text into an SEO-optimized, structured blog post with title, intro, chapters, and conclusion using the GPT-4o-mini OpenAI node combined with the Langchain node.
Dynamic Image Creation: Generates vibrant blog post images based on the post title with Pollinations.ai API and uploads them to WordPress setting as featured media.
WordPress Draft Creation: Automatically creates a draft WordPress post with the AI-generated content and attaches the featured image.
Human-In-The-Loop Approval via Gmail: Sends the draft post to a reviewer via Gmail awaiting approval or rejection, ensuring quality control before publishing.
Multi-Channel Notifications: Once approved and published, sends notifications via Gmail and Telegram to inform stakeholders.

This workflow saves Joe over 8 hours weekly by automating repetitive content creation tasks, improves blog quality with AI and human oversight, and integrates tightly with WordPress publishing and communication tools.

3. Prerequisites ⚙️

n8n account: To run and deploy the workflow.
OpenAI account 🔑: For AI-powered blog content generation (GPT-4 or compatible).
WordPress account 🔑: With API access for creating posts and uploading media.
Gmail account 📧: To send blog post approval requests and final notifications.
Telegram account 💬: For sending blog post update notifications.
Pollinations.ai API: For AI-generated blog post images.

Optional: You can self-host n8n for more control with providers like Hostinger.

4. Step-by-Step Guide

Step 1: Set Up PDF Upload Web Form Trigger

Navigate to your n8n editor and add the Form Trigger node named Upload PDF. Configure the form to accept single PDF files only.

Parameters:

Path: pdf
Form Title: PDF2Blog
Form Field: File input accepting .pdf files, required

You should see the webhook URL generated for this form. This URL is the endpoint users will visit to upload PDF documents.

Common mistake: Forgetting to specify .pdf as accepted file type or allowing multiple files will cause extraction errors.

Step 2: Extract Text from Uploaded PDFs

Add the Extract Text from File node (Extract Text) and connect it after the form trigger.

Set the operation to pdf and use the binary property Upload_PDF_File to extract text.

After this step, the workflow will have the raw text content from the PDF ready for AI processing.

Common mistake: Using wrong binary property name will yield empty text.

Step 3: Generate SEO-Friendly Blog Post Using AI

Add the Langchain Chain LLM node (Write Blog Post) connected to the extraction output.

Paste the JavaScript expression output of Extract Text node’s text into the node’s input and add this detailed prompt specifying an SEO-friendly title, structured content with intro, chapters, and conclusion, using proper HTML formatting.

The prompt example (already in the workflow) demands:

Title under 10 words, no colons
Content with introduction (~150-200 words), 6-8 chapters (~300-400 words each), and conclusion (~200-250 words)
Proper HTML tags and engaging formatting

Common mistake: Not structuring the prompt properly leads to poor blog formatting.

Step 4: Extract Title & Full Content from AI Output via Code Node

Use a Code node (Get Blog Post) to parse the AI-generated HTML content and extract the main title from the first

tag.

Code snippet (JavaScript):

const htmlContent = $input.first().json.text;
const titleRegex = /(.*?)/s;
const match = htmlContent.match(titleRegex);
const title = match ? match[1] : '';
return [{ json: { title: title, content: htmlContent } }];

This prepares the title and content properties for further conditional checks and WordPress posting.

Step 5: Validation Check for Title & Content Presence

Add an If node (Is there Title & Content?) to ensure both the title and content are present before proceeding.

Under Conditions, check that both $json.title and $json.content are not empty.

Common mistake: Missing this validation could lead to empty drafts being created.

Step 6: Human-In-The-Loop Approval via Gmail

If validation passes, the workflow sends the blog for approval via the Gmail node (Human In The Loop Approve Blog Post) configured to send and wait for reply.

Parameters:

Send To: [email protected] (replace with your reviewer email)
Subject: Approval Required for “{{ $json.title }}”
Message Body: blog post content HTML
Operation: Send and wait
Approval type: double (explicit accept or reject)

The workflow pauses here until the reviewer clicks approve or reject.

Common mistake: Incorrect Gmail OAuth2 credential setup can cause send failures.

Step 7: Process Approval Decision

Add an If node (Is Approved?) evaluating if $json.data.approved is true.

If approved, continue to WordPress post creation. Otherwise, send an error notification via the Telegram node (Send Error Message).

Step 8: Create WordPress Draft Post

Add the WordPress node (Create WordPress Post) using the extracted title and HTML content to create a post in draft status.

All posts are created unpublished until approval happens.

Common mistake: Incorrect WordPress API credentials or missing required fields lead to failures.

Step 9: Generate Blog Post Image

Trigger the HTTP Request node (pollinations.ai) to create a vibrant blog image based on the blog title.

Example URL:

https://image.pollinations.ai/prompt/{{ $('Get Blog Post').item.json.title }} and avoid adding text and keep the image vibrant.

This node fetches image binary data to be uploaded next.

Step 10: Upload Image to WordPress Media Library

Use another HTTP Request node (Upload Image to WordPress) to upload the generated image as binary data to the WordPress media endpoint.

Set Headers: Content-Disposition: attachment; filename="cover-image-{{post_id}}.jpeg"

Authentication uses predefined WordPress API credentials.

Common mistake: Forgetting to replace [YOUR-WORDPRESS-SITE.com] with actual site URL results in errors.

Step 11: Set Featured Image on WordPress Post

Next, update the WordPress post’s featured_media property using a HTTP Request node (Set Image on WordPress Post), linking the uploaded image ID.

This enhances blog appearance on the front end.

Step 12: Convert Content to Markdown & Notify

Use the Markdown node to convert the post content into markdown format for Telegram notification.

Then, merge notifications Telegram Partial Blog and Gmail Final Blog to inform Joe or stakeholders of the published blog.

Step 13: Send Final Notifications via Gmail and Telegram

The Gmail node (Gmail Final Blog) sends the full blog content to Joe’s email.

Simultaneously, the Telegram node (Telegram Partial Blog) sends a photo preview with a caption snippet.

5. Customizations ✏️

Change Blog Reviewer Email: In the Human In The Loop Approve Blog Post Gmail node, update the sendTo field to your reviewer’s email address to direct approval requests correctly.
Adjust AI Blog Structure: Modify the prompt in the Write Blog Post Langchain node to include specific branding language, additional sections, or focus areas to better match your blog style.
Modify Image Style: Change the URL in the pollinations.ai HTTP node to tweak image style by editing the prompt, e.g., “modern, flat design” or “minimalist” themes.
Publish Immediately on Approval: In the Create WordPress Post node, set the post status to “publish” instead of “draft” for immediate go-live upon approval.
Add Additional Notification Channels: Integrate Slack or Microsoft Teams nodes to send notifications besides Gmail and Telegram.

6. Troubleshooting 🔧

Problem: “Failed to extract text from PDF”
Cause: The uploaded file is not a valid PDF or the binary property name is incorrect.
Solution: Ensure the upload node accepts only .pdf files and the Extract Text node uses the correct binary property Upload_PDF_File.

Problem: “Gmail approval emails not sending”
Cause: Improper setup of Gmail OAuth2 credentials or API limits.
Solution: Reconfigure Gmail credentials via n8n settings, check token validity, and ensure quota is sufficient.

Problem: “WordPress API media upload fails”
Cause: Incorrect WordPress site URL or missing authentication headers.
Solution: Replace placeholder URLs with your actual WordPress site, verify authentication credentials are set, and header parameters are properly passed.

7. Pre-Production Checklist ✅

Verify API credentials for OpenAI, WordPress, Gmail, and Telegram are correctly configured.
Test PDF upload endpoint by submitting sample PDF files to confirm text extraction works.
Run the workflow fully with test data and check that the blog post is created as draft in WordPress with featured image set.
Validate Gmail approval emails are delivered and the workflow pauses awaiting review.
Test approval and rejection paths to confirm correct branching behavior.

8. Deployment Guide

Activate the workflow in your n8n editor by toggling the active switch. Set up monitored logs and error notifications to track workflow health. Regularly review approval turnaround times and post publication accuracy.

This workflow requires your WordPress site and email systems to be online and accessible. For higher volumes, consider n8n’s self-hosting option to secure API limits and reduce latency.

9. FAQs

Q1: Can I use a different AI provider instead of OpenAI?
A: Yes, you can replace the OpenAI node with other supported AI nodes compatible with n8n, adjusting prompts accordingly.

Q2: Does this workflow consume many API credits?
A: The OpenAI node usage depends on your prompt length; consider token quotas to manage costs effectively.

Q3: Is my data secure when using Gmail and WordPress APIs?
A: Yes, using OAuth2 credentials ensures secure authorization without exposing passwords, but always follow best security practices.

10. Conclusion

By following this comprehensive tutorial, you’ve built a powerful automation to transform PDF documents into SEO-friendly WordPress blog posts with human approval baked right in via Gmail. This workflow saves hours each week, reduces content errors, and boosts your publishing efficiency without sacrificing quality.

Next, you might explore automating social media promotion of posts, integrating additional AI-based content enrichment, or customizing post formats per your brand guidelines.

Keep experimenting and enjoy the freedom afforded by smart automation! ⚙️

Automate WordPress Blog Creation from PDFs with Gmail Approval