--- title: Function Calling | daily.dev description: A screencast tutorial demonstrating how to integrate LLM function calling (tool use) into a Ruby on Rails application. It walks through building an inventory... canonical: https://daily.dev/posts/function-calling-fnaq4lqca twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Function Calling | daily.dev og:description: A screencast tutorial demonstrating how to integrate LLM function calling (tool use) into a Ruby on Rails application. It walks through building an inventory... og:url: https://daily.dev/posts/function-calling-fnaq4lqca og:image: https://api.daily.dev/og/posts/FnAQ4LQca.png og:image:alt: Function Calling 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. # Function Calling **[RUBYLAND](https://daily.dev/sources/rubyla)** · 2 min read · 0 upvotes · 0 comments ## Summary A screencast tutorial demonstrating how to integrate LLM function calling (tool use) into a Ruby on Rails application. It walks through building an inventory assistant that uses the ruby-openai gem to query GPT-4o-mini, defines a check_inventory tool that queries an ActiveRecord Product model via LIKE search, and wires everything together with a simple Rails controller and ERB view using Turbo/Hotwire for form submission. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Building an AI agent inside a 7-year old Rails application](https://daily.dev/posts/building-an-ai-agent-inside-a-7-year-old-rails-application-wcc3vvswg) · Ruby Flow · 1 upvotes · 0 comments - [How to implement AI agents in Rails with RubyLLM](https://daily.dev/posts/how-to-implement-ai-agents-in-rails-with-rubyllm-2fndidsec) · Ruby Flow · 0 upvotes · 0 comments - [How to Build An AI Agent with Function Calling and GPT-5](https://daily.dev/posts/how-to-build-an-ai-agent-with-function-calling-and-gpt-5-yvu3rt1pf) · Towards Data Science · 0 upvotes · 0 comments - [Building LLM-Powered Applications in Ruby: A Practical Introduction](https://daily.dev/posts/building-llm-powered-applications-in-ruby-a-practical-introduction-uawvtziok) · RUBYLAND · 1 upvotes · 0 comments --- Tags: [#devtools](https://daily.dev/tags/devtools), [#openai](https://daily.dev/tags/openai), [#ruby](https://daily.dev/tags/ruby), [#rails](https://daily.dev/tags/rails) [View this post on daily.dev](https://daily.dev/posts/function-calling-fnaq4lqca) ```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":"Function Calling","url":"https://daily.dev/posts/function-calling-fnaq4lqca","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/function-calling-fnaq4lqca"},"datePublished":"2026-08-03T02:21:27.371Z","dateModified":"2026-08-03T02:21:45.555Z","description":"A screencast tutorial demonstrating how to integrate LLM function calling (tool use) into a Ruby on Rails application. 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