--- title: The complete guide to Convex | daily.dev description: Convex combines a database, backend functions, and live updates in one TypeScript API, letting a frontend stay current without polling or a separate WebSocket... canonical: https://daily.dev/posts/the-complete-guide-to-convex-2odvrxwej twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: The complete guide to Convex | daily.dev og:description: Convex combines a database, backend functions, and live updates in one TypeScript API, letting a frontend stay current without polling or a separate WebSocket... og:url: https://daily.dev/posts/the-complete-guide-to-convex-2odvrxwej og:image: https://api.daily.dev/og/posts/2odVRxWeJ.png og:image:alt: The complete guide to Convex 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. # The complete guide to Convex **[Flavio Copes](https://daily.dev/sources/flaviocopes)** · 62 min read · 1 upvotes · 0 comments ## Summary Convex combines a database, backend functions, and live updates in one TypeScript API, letting a frontend stay current without polling or a separate WebSocket layer. This guide builds a task app with Astro and TypeScript, covering queries, mutations, actions, indexes, full-text search, Clerk authentication, pagination, file storage, scheduled background jobs, and tests. Queries read a consistent snapshot and track dependencies for subscriptions, mutations write transactionally with rollback on failure, and actions handle external calls like fetch. It also covers optimistic concurrency control, owner-based authorization, and avoiding unbounded `.collect()` calls. ## 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 difference between a Convex query, mutation, and action? A query reads the database directly and computes a result from a consistent snapshot, tracking dependencies so subscribed clients get live updates. A mutation reads and writes the database inside a transaction that rolls back if it throws. An action can call external APIs via fetch and reach the database only indirectly, through queries and mutations it calls. _Developers designing a Convex backend can dig deeper into these patterns on daily.dev._ ### How do I prevent two Convex users from seeing each other's tasks? Derive ownership from a verified server-side identity rather than trusting client input, store an owner field on each document, and query through an index like by_owner that filters on that identity. Authorization checks, such as comparing task.owner to the caller's identity, must run inside the mutation or query itself, since hiding a UI button does not protect the backend function. _Anyone wiring up per-user data access can compare authorization approaches on daily.dev._ ### Why shouldn't I use .collect() to fetch all records in a Convex query? The .collect() method returns every matching document, which is fine only for a small, permanently bounded dataset, but a growing collection like a user's task history is not permanently bounded. Use .take() for a deliberately limited view or .paginate() for browsing an expanding result set, since returning thousands of rows also wastes network bandwidth and client work. _Developers tuning database read patterns can track performance tradeoffs like this on daily.dev._ ## Similar posts on daily.dev - [Convex is now a one-command backend for Expo apps — Expo blog](https://daily.dev/posts/convex-is-now-a-one-command-backend-for-expo-apps-expo-blog-hxqzz0f4u) · Expo Blog · 39 upvotes · 1 comments - [Convex Vercel Marketplace Integration](https://daily.dev/posts/convex-vercel-marketplace-integration-njmvhjxdg) · Convex · 16 upvotes · 0 comments - [Build and Publish a Full-Stack Mobile App with AI](https://daily.dev/posts/build-and-publish-a-full-stack-mobile-app-with-ai-xumtefxsq) · freeCodeCamp · 7 upvotes · 0 comments - [Product Updates - Volume 25](https://daily.dev/posts/product-updates---volume-25-b8axwqaec) · Convex · 0 upvotes · 0 comments --- Tags: [#backend](https://daily.dev/tags/backend), [#typescript](https://daily.dev/tags/typescript), [#authentication](https://daily.dev/tags/authentication), [#convex](https://daily.dev/tags/convex) [View this post on daily.dev](https://daily.dev/posts/the-complete-guide-to-convex-2odvrxwej) ```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":"The complete guide to Convex","url":"https://daily.dev/posts/the-complete-guide-to-convex-2odvrxwej","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/the-complete-guide-to-convex-2odvrxwej"},"datePublished":"2026-10-26T11:32:46.675Z","dateModified":"2026-10-26T11:40:42.537Z","description":"Convex combines a database, backend functions, and live updates in one TypeScript API, letting a frontend stay current without polling or a separate WebSocket...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/9780b81bf47ca293753abcb40ecd38b1?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/9780b81bf47ca293753abcb40ecd38b1?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Flavio Copes","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Flavio Copes","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/1f2dbd275797411bbd37bfdaaf0951a9","url":"https://daily.dev/sources/flaviocopes"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/the-complete-guide-to-convex-2odvrxwej","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"backend,typescript,authentication,convex","timeRequired":"PT62M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Flavio Copes","item":"https://daily.dev/sources/flaviocopes"},{"@type":"ListItem","position":3,"name":"The complete guide to Convex"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/the-complete-guide-to-convex-2odvrxwej#faq","mainEntity":[{"@type":"Question","name":"What is the difference between a Convex query, mutation, and action?","acceptedAnswer":{"@type":"Answer","text":"A query reads the database directly and computes a result from a consistent snapshot, tracking dependencies so subscribed clients get live updates. 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