How to Auto-Generate Social Media Captions From New Blog Posts

Watch your RSS feed, have AI draft platform-specific captions, and queue them for posting automatically.

8 minBeginner

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Every time you publish a blog post, you probably want a few social captions to go with it. This Zap watches your site's RSS feed, sends each new post to an AI step that writes captions tuned per platform, and drops the drafts where you can review or schedule them.

What you need

A Zapier account
A public RSS feed for your blog (most platforms have /feed or /rss)
A destination such as a Google Doc, Buffer, or a Slack channel
About 10 minutes

Step 1: Trigger on a new RSS item

Add the RSS by Zapier trigger New Item in Feed. Paste your feed URL and test. Zapier loads the latest post so you can see fields like Title, Link, and Description.

RSS feed check

$curl -s https://setuproll.com/feed | head

<item>

<title>How to Build Your First Zap</title>

Confirms the feed is valid before connecting it.

Step 2: Draft captions with AI

Add an AI action and map the post Title and Description into the prompt. Ask for several captions at once, each labeled by platform, so one run produces everything you need.

Caption prompt

Write 3 social captions for this blog post.
Match each platform's tone and length:

X (under 240 chars, punchy, 1 emoji):
LinkedIn (3 short lines, professional):
Instagram (friendly, 3 relevant hashtags):

Title: {{Title}}
Summary: {{Description}}
Link: {{Link}}

AI captions output

X: Just published: build your first Zap with an

AI step in 8 min. No code. -> {{Link}}

LinkedIn: New guide on Setuproll.

Drop AI into any workflow with one action...

Instagram: Your first AI automation, made simple.

#zapier #automation #nocode

One AI step produces all three drafts at once.

Step 3: Send drafts somewhere reviewable

Add a final action that delivers the drafts. A Slack message or a new Google Doc works well for a human review step. If you trust the output, connect Buffer or a publishing app to queue posts directly.

Keep a human in the loop at first

Send to Slack for the first week and skim each batch. Once the captions are consistently on-brand, switch the final action to your scheduler to fully automate.

Result: You publish a post and, minutes later, three ready-to-edit captions tuned for X, LinkedIn, and Instagram are waiting for a quick review or auto-queued.