--- title: Practical Kotlin Multiplatform: Implementing the... description: A step-by-step walkthrough of implementing a Firebase sign-up API call using Ktor in a Kotlin Multiplatform project. Covers defining a... canonical: https://daily.dev/posts/practical-kotlin-multiplatform-implementing-the-firebase-sign-up-operation-with-ktor-jddicwq8t twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Practical Kotlin Multiplatform: Implementing the Firebase Sign-up Operation with Ktor | daily.dev og:description: A step-by-step walkthrough of implementing a Firebase sign-up API call using Ktor in a Kotlin Multiplatform project. Covers defining a... og:url: https://daily.dev/posts/practical-kotlin-multiplatform-implementing-the-firebase-sign-up-operation-with-ktor-jddicwq8t og:image: https://api.daily.dev/og/posts/jDDiCWQ8T.png og:image:alt: Practical Kotlin Multiplatform: Implementing the Firebase Sign-up Operation with Ktor 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. # Practical Kotlin Multiplatform: Implementing the Firebase Sign-up Operation with Ktor **[Joe Birch](https://daily.dev/sources/joebirch)** · 6 min read · 0 upvotes · 0 comments ## Summary A step-by-step walkthrough of implementing a Firebase sign-up API call using Ktor in a Kotlin Multiplatform project. Covers defining a FirebaseAuthenticationRepository interface, implementing it in an AuthenticationRemote class, making a POST request to the Firebase Identity Toolkit endpoint, setting form-encoded content type, appending the API key as a query parameter, and passing email, password, and returnSecureToken as form body parameters. Error handling is done via try/catch returning an empty AuthenticationResult on failure. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Practical Kotlin Multiplatform: Creating the Firebase Auth Remote Store with Ktor](https://daily.dev/posts/practical-kotlin-multiplatform-creating-the-firebase-auth-remote-store-with-ktor-z18pllgtl) · Joe Birch · 0 upvotes · 0 comments - [Practical Kotlin Multiplatform: Setting up the Kotlin Multiplatform Networking Module with Ktor](https://daily.dev/posts/practical-kotlin-multiplatform-setting-up-the-kotlin-multiplatform-networking-module-with-ktor-z7mvnl8di) · Joe Birch · 0 upvotes · 0 comments --- Tags: [#authentication](https://daily.dev/tags/authentication), [#kotlin](https://daily.dev/tags/kotlin), [#firebase](https://daily.dev/tags/firebase), [#ktor](https://daily.dev/tags/ktor) [View this post on daily.dev](https://daily.dev/posts/practical-kotlin-multiplatform-implementing-the-firebase-sign-up-operation-with-ktor-jddicwq8t) ```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":"Practical Kotlin Multiplatform: Implementing the Firebase Sign-up Operation with Ktor","url":"https://daily.dev/posts/practical-kotlin-multiplatform-implementing-the-firebase-sign-up-operation-with-ktor-jddicwq8t","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/practical-kotlin-multiplatform-implementing-the-firebase-sign-up-operation-with-ktor-jddicwq8t"},"datePublished":"2026-07-26T07:46:12.168Z","dateModified":"2026-07-26T07:46:29.601Z","description":"A step-by-step walkthrough of implementing a Firebase sign-up API call using Ktor in a Kotlin Multiplatform project. Covers defining a...","image":"https://media.daily.dev/image/upload/s--P4t4XyoV--/f_auto/v1722860399/public/Placeholder%2001","thumbnailUrl":"https://media.daily.dev/image/upload/s--P4t4XyoV--/f_auto/v1722860399/public/Placeholder%2001","isAccessibleForFree":true,"articleSection":"Joe Birch","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":"Joe Birch","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/58a02bef21dd4a1cbc4c5abdb0151d2d","url":"https://daily.dev/sources/joebirch"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/practical-kotlin-multiplatform-implementing-the-firebase-sign-up-operation-with-ktor-jddicwq8t","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"authentication,kotlin,firebase,ktor","timeRequired":"PT6M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Joe Birch","item":"https://daily.dev/sources/joebirch"},{"@type":"ListItem","position":3,"name":"Practical Kotlin Multiplatform: Implementing the Firebase Sign-up Operation with Ktor"}]} ```