AI Carousel Caption & Template Editor Workflow

Overview

This workflow is a caption-only carousel text generator built in n8n. It turns any raw LinkedIn post or text input into 3 short, slide-ready title + subtext captions and renders those captions onto image templates. Output is a single aggregated response with markdown image embeds and download links.

Workflow Structure

• Input: Chat UI trigger accepts text and optional template selection.
• Core AI: Agent cleans input and returns structured JSON with 3 caption pairs.
• Template Rendering: Edit Image nodes render title and subtext on chosen templates.
• Storage: Rendered images uploaded to S3.
• Aggregate Output: Aggregate node builds final markdown response with embeds and download links.

Chat Trigger (Frontend)

• Trigger: When chat message received
  • UI accepts plain text post.
  • allowFileUploads optional for template images.
  • SessionId preserved for context.

AI Agent (Core)

• Node name: AI Agent
• Model: Mistral Cloud Chat Model (mistral-small-latest)
• Behavior:
  • Clean input (remove stray formatting like \n and ** but keep emojis).
  • Produce exactly one JSON object with fields: postclean, title1, subtext1, title2, subtext2, title3, subtext3.
  • Titles must be short (max 5 words). Subtext 1 or 2 short sentences, max 7 words per line if possible.
  • Agent must return valid JSON to be parsed by the Structured Output Parser.

Structured Output Parser

• Node name: Structured Output Parser
• Validates agent JSON and prevents downstream errors. If parsing fails, stop and surface error.

Normalize Title Nodes

• Nodes: normalize title,name 1, normalize title,name 2, normalize title,name 3 (and optional 4)
• Map parsed output into node fields: title, subtext, safeName (safe filename for exports).

Template Images

• Source: Google Drive template PNGs (download via Google Drive nodes) or provided upload.
• Keep templates high resolution and consistent aspect ratio.

Edit Image Nodes (Render Captions)

• Nodes: Edit Image 1, Edit Image2, Edit Image3, Edit Image3 (or Edit Image3/Edit Image4 as available)
• MultiStep operations render:
  • Title text (font, size, position)
  • Subtext (font, size, position)
• This is where caption text is added to the template.

Upload to S3

• Nodes: S3
• Upload rendered images to bucketname using safeName filenames. Confirm public access or use signed URLs.

Get S3 URLs and Aggregate

• Nodes: get s3 url image 1, get s3 url image 2, get s3 url image 3, get s3 url image 4
• Merge + Aggregate: Merge1 and Aggregate collect image items.
• Output Format: output format builds a single markdown message:
  • Inline image embeds ![image](<s3-url>)
  • Download links per image.

Integrations Used

Agent System Prompt Summary

You are a data formatter and banner caption creator. Clean the user input (remove stray newlines and markup but keep emojis). Return a single JSON object with postclean, title1/subtext1, title2/subtext2, title3/subtext3. Titles must be short (max 5 words). Subtext should be 1 to 2 short sentences, useful and value adding. Respond only with JSON.

Key Features

• ✅ Caption only output: 3 short slide-ready caption pairs.
• ✅ Structured JSON output enforced by a parser for reliability.
• ✅ Renders captions onto image templates using Edit Image nodes.
• ✅ Uploads images to S3 and returns markdown embeds plus download links.
• ✅ Template editable: swap Google Drive background templates or upload your own.
• ✅ Zero guess formatting: agent must produce parseable JSON to avoid downstream failures.

Summary

A compact n8n workflow that converts raw LinkedIn text into a caption-only carousel with rendered images. It enforces tight caption rules, validates AI JSON, places captions on templates, uploads images, and returns a single ready-to-post markdown payload.

Need Help or More Workflows?

We can wire this into your account, replace templates, or customize fonts, positions, and export options.
💡 We can help you set it up for free — from connecting credentials to deploying it live.

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Website: https://www.digitalbiz.tech
LinkedIn: https://www.linkedin.com/company/digitalbiztech/
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