Step 2: Connect Google Drive Retrieval

Download the newly created file so it can be used for caption generation and downstream posting.

1. Add the Retrieve Drive File node and connect it to Drive File Creation Trigger.
2. Set Operation to download.
3. Set File ID to {{ $json.id }}.
4. Credential Required: Connect your googleDriveOAuth2Api credentials.

Step 3: Set Up AI Caption Generation

Generate an Instagram-ready caption using OpenAI based on the incoming file name.

1. Add the Generate Caption Text node and connect it to Retrieve Drive File.
2. Set Model to gpt-4o-mini.
3. In Messages, set the prompt content to:
   =Generate an engaging Instagram caption for a {{ $('Drive File Creation Trigger').item.json.name }} about [Description]. Include: \n2-3 sentences with emojis\n\n3-5 relevant hashtags\n\nA call-to-action\n\nKeep it under 150 characters as you are skilled at writing detailed captions based on a file name. write a clear, engaging caption that helps viewers understand and appreciate the post withoutj using too many whimsical words or using too many adjectives. make it relatable and suitable for an instagram audience, encouraging people to connect with the post and respond in the comments.
4. Credential Required: Connect your openAiApi credentials.

Step 4: Connect Google Sheets Logging

Store file metadata and the generated caption in Google Sheets to feed the Instagram Graph steps.

1. Add the Append Sheet Record node and connect it to Generate Caption Text.
2. Set Operation to appendOrUpdate.
3. Set Document ID to [YOUR_ID] and Sheet Name to gid=0 (Sheet1).
4. Map columns to expressions:
   Name → {{ $('Retrieve Drive File').item.json.name }}
   Captions → {{ $json.choices[0].message.content }}
   Reel Urls → {{ $('Retrieve Drive File').item.json.webViewLink }}
   Reel Thumbnail → {{ $('Retrieve Drive File').item.json.thumbnailLink }}
5. Credential Required: Connect your googleSheetsOAuth2Api credentials.

Step 5: Configure Instagram Graph API Posting

Prepare and publish the Instagram Reel using Meta’s Graph API endpoints.

1. Add the Prepare IG Media via Graph node and connect it to Append Sheet Record.
2. Set Edge to media and Node to [YOUR_ID].
3. Set Graph API Version to v22.0 and HTTP Request Method to POST.
4. Add query parameters:
   video_url → {{ $json['Reel Urls '] }}
   media-type → REELS
   caption → {{ $json.Captions }}
   image_url → {{ $json['Reel Thumbnail'] }}
5. Add the Publish IG Media node and connect it to Prepare IG Media via Graph.
6. Set Edge to media_publish, Node to [YOUR_ID], Host URL to graph-video.facebook.com, and Graph API Version to v22.0.
7. Set query parameter creation_id to {{ $json.id }}.
8. Credential Required: Connect your facebookGraphApi credentials to both Prepare IG Media via Graph and Publish IG Media.

Step 6: Test and Activate Your Workflow

Verify the end-to-end pipeline before turning it on for production posting.

1. In n8n, click Execute Workflow and upload a test file into the watched Google Drive folder.
2. Confirm that Retrieve Drive File downloads the file and Generate Caption Text returns a caption.
3. Check Append Sheet Record for a new row containing the file name, caption, reel URL, and thumbnail URL.
4. Ensure Prepare IG Media via Graph returns a media id and Publish IG Media successfully publishes the Reel.
5. When successful, toggle the workflow to Active to enable continuous posting.