--- title: Build a Trending Topic System with Zapier and Custom Code description: A practical walkthrough of building a weekly trending topic research system using Zapier's MCP server and SDK. The system automatically pulls content from... canonical: https://daily.dev/posts/build-a-trending-topic-system-with-zapier-and-custom-code-xonflpmmc twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Build a Trending Topic System with Zapier and Custom Code | daily.dev og:description: A practical walkthrough of building a weekly trending topic research system using Zapier's MCP server and SDK. The system automatically pulls content from... og:url: https://daily.dev/posts/build-a-trending-topic-system-with-zapier-and-custom-code-xonflpmmc og:image: https://api.daily.dev/og/posts/xonFlpmmC.png og:image:alt: Build a Trending Topic System with Zapier and Custom Code og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Build a Trending Topic System with Zapier and Custom Code **[ByteMonk](https://daily.dev/sources/bytemonk)** · 8 min read · 0 upvotes · 0 comments ## Summary A practical walkthrough of building a weekly trending topic research system using Zapier's MCP server and SDK. The system automatically pulls content from Hacker News, Reddit, and GitHub every Monday, scores topics by audience fit and search demand, and drops a ranked list of video ideas into Notion. The post covers two approaches: a no-code chat-based MCP setup for quick prototyping, and a code-based SDK approach for reliable scheduled automation. It also addresses a critical security concern — prompt injection attacks on AI agents — explaining the 'lethal trifecta' risk when an agent can simultaneously read untrusted internet content, access private data, and send outbound messages. The recommended mitigation is the 'rule of two': never let an unsupervised agent hold all three powers, require human approval before anything is sent out, and apply least-privilege access. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is the 'lethal trifecta' risk in AI agents and how do I mitigate it? An AI agent becomes dangerous when it simultaneously reads untrusted internet content, accesses private data, and can send outbound messages. Security researchers call this combination 'lethal trifecta' because a malicious instruction embedded in public content (like a Reddit comment) can hijack the agent — the same root cause as SQL injection. The mitigation is the 'rule of two': never let an unsupervised agent hold all three powers at once, require human approval before outbound actions, and apply read-only access wherever possible. _Developers building autonomous agents track emerging prompt injection mitigations on daily.dev._ ### What is the difference between using Zapier MCP vs the Zapier SDK for AI agents? Zapier MCP is an on-demand connection used in chat interfaces — the agent only runs when you manually prompt it, making it ideal for quick prototyping. The Zapier SDK is for code-based, scheduled automation: you install it into a project, authenticate once, and the agent runs on a fixed schedule without human intervention. Both access the same thousands of app integrations, but the SDK is suited for production workflows. _Teams deciding between MCP and SDK approaches for agent automation find real-world comparisons on daily.dev._ ## Similar posts on daily.dev - [\[Hands-on\] Build an MCP-powered Deep Researcher](https://daily.dev/posts/hands-on-build-an-mcp-powered-deep-researcher-bs06e3rox) · Daily Dose of Data Science \| Avi Chawla \| Substack · 6 upvotes · 1 comments - [Reclaim Your Time – Master Automation with Zapier](https://daily.dev/posts/reclaim-your-time-master-automation-with-zapier-rwbyhngmj) · freeCodeCamp · 1 upvotes · 0 comments - [Agent-Reach: Giving Your AI Eyes on the Web](https://daily.dev/posts/agent-reach-giving-your-ai-eyes-on-the-web-koptqk6go) · SitePoint · 1 upvotes · 0 comments --- Tags: [#automation](https://daily.dev/tags/automation), [#ai-agents](https://daily.dev/tags/ai-agents), [#mcp](https://daily.dev/tags/mcp), [#prompt-injection](https://daily.dev/tags/prompt-injection) [View this post on daily.dev](https://daily.dev/posts/build-a-trending-topic-system-with-zapier-and-custom-code-xonflpmmc) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Build a Trending Topic System with Zapier and Custom Code","url":"https://daily.dev/posts/build-a-trending-topic-system-with-zapier-and-custom-code-xonflpmmc","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/build-a-trending-topic-system-with-zapier-and-custom-code-xonflpmmc"},"datePublished":"2026-08-10T03:46:37.948Z","dateModified":"2026-08-10T03:47:06.893Z","description":"A practical walkthrough of building a weekly trending topic research system using Zapier's MCP server and SDK. 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