Step 1: Create Google Apps Script

1. Go to script.google.com
2. Click "New Project"
3. Replace the default code with the script below
4. Save the project with a name like "Blog Generator API"

function doPost(e) {
  try {
    const data = JSON.parse(e.postData.contents);
    const sheet = SpreadsheetApp.openById('YOUR_SHEET_ID_HERE');
    const blogSheet = sheet.getSheetByName('Blog Posts') || sheet.insertSheet('Blog Posts');
    
    // Create headers if they don't exist
    if (blogSheet.getLastRow() === 0) {
      blogSheet.getRange(1, 1, 1, 10).setValues([[
        'ID', 'Title', 'Subject', 'Primary Keyword', 'Target Audience', 
        'Status', 'Date Created', 'Author', 'Keywords', 'Excerpt'
      ]]);
    }
    
    // Add the new blog post data
    blogSheet.appendRow([
      data.id,
      data.title,
      data.subject,
      data.primaryKeyword,
      data.targetAudience,
      data.status,
      data.dateCreated,
      data.author,
      data.keywords.join(', '),
      data.excerpt
    ]);
    
    return ContentService.createTextOutput(JSON.stringify({
      success: true,
      message: 'Blog post added successfully'
    })).setMimeType(ContentService.MimeType.JSON);
    
  } catch (error) {
    return ContentService.createTextOutput(JSON.stringify({
      success: false,
      error: error.toString()
    })).setMimeType(ContentService.MimeType.JSON);
  }
}

function doGet() {
  return ContentService.createTextOutput('Blog Generator API is running');
}

Step 2: Configure and Deploy

1. Replace 'YOUR_SHEET_ID_HERE' with your actual Google Sheets ID
2. Click "Deploy" → "New Deployment"
3. Choose "Web app" as the type
4. Set "Execute as" to "Me"
5. Set "Who has access" to "Anyone"
6. Click "Deploy" and copy the Web App URL
7. Paste the URL in the settings above