How to Build a Backend for ASP.NET Core?

introduction in this tutorial, you’ll learn how to build a backend for asp net core using back4app by integrating back4app’s essential features—such as database management, cloud code, rest and graphql apis, user authentication, and real time queries—you’ll gain a complete backend solution for your asp net core applications this approach supports building scalable web applications, handling server side logic with minimal setup with back4app, you can speed up backend development for your asp net core project you'll take advantage of an open source platform that supports a reliable web api infrastructure, database connectivity, and robust cloud functions by the end of this tutorial, you’ll have a working foundation for a secure and extensible backend that offers improved user experiences and handles real time data you can then extend your net core solution or integrate it with other services as needed prerequisites a back4app account and a new back4app project getting started with back4app https //www back4app com/docs/get started/new parse app if you do not have an account, you can create one for free asp net core development environment ensure you have the net sdk (version 6 0 or above) installed download net https //dotnet microsoft com/en us/download familiarity with c# and asp net core official asp net core docs https //learn microsoft com/en us/aspnet/core/?view=aspnetcore 6 0 optional if you plan to use parse net sdk, you’ll need parse sdk dotnet https //github com/parse community/parse sdk dotnet or references in your csproj file ensure you have all of these prerequisites in place before you begin having your back4app project and asp net core environment ready will make the steps much easier to follow step 1 – creating a new project on back4app and connecting why this step? your asp net core backend begins with a back4app project this project is your server side foundation, managing your database, security rules, and app settings creating the project log in to your back4app account click “new app” from your dashboard name your app (e g , “aspnetcore backend tutorial”) after creation, you’ll see it listed on your dashboard this new app is your main hub for backend development tasks installing the parse net sdk (optional) while you can use rest api or graphql directly, the parse net sdk can simplify data operations in your asp net core solutions if you want to integrate it add the parse sdk to your csproj or via nuget package manager initialize the sdk in your asp net core application (e g , program cs or startup cs ) replace the placeholders with credentials from your back4app app’s “app settings” > “security & keys ” this connects your asp net core project to back4app’s server side environment step 2 – setting up the database 1\ creating a data model use the back4app dashboard to define your class schema for example, a todo class with columns like title (string) and iscompleted (boolean) 2\ creating a data model using the ai agent open the ai agent in your back4app dashboard and describe your data model for example, “create a new todo class for my asp net core applications ” the ai agent then sets up the schema for you 3\ reading and writing data using the parse net sdk here’s how you might create and fetch todo items in c# using parse; // create a new todo public async task\<parseobject> createtodo(string title, bool iscompleted) { var todo = new parseobject("todo") { { "title", title }, { "iscompleted", iscompleted } }; return await todo saveasync(); } // fetch all todos public async task\<ienumerable\<parseobject>> fetchtodos() { var query = new parsequery\<parseobject>("todo"); return await query findasync(); } 4\ reading and writing data using rest api alternatively, you can use a rest api approach curl x post \\ h "x parse application id your application id" \\ h "x parse rest api key your rest api key" \\ h "content type application/json" \\ d '{"title" "buy groceries", "iscompleted" false}' \\ https //parseapi back4app com/classes/todo 5\ reading and writing data using graphql api to use graphql , send queries or mutations to the back4app graphql endpoint mutation { createtodo(input { fields { title "clean the house" iscompleted false } }) { todo { objectid title iscompleted } } } 6\ working with live queries enable real time updates by turning on live queries in your dashboard (under server settings ) then use the net or websocket approach to subscribe this keeps data fresh in your web application without extra calls step 3 – applying security with acls and clps acls and clps overview acls (access control lists) secure individual objects clps (class level permissions) secure entire classes this layered approach keeps data safe in your asp net core environment setting up class level permissions open the database tab in your back4app dashboard select the todo class click class level permissions customize read/write for public or authenticated roles configuring acls in code with the parse net sdk, you can set acls at object level var todo = new parseobject("todo") { { "title", "private task" } }; // restrict read/write to only a particular user var acl = new parseacl(); acl setpublicreadaccess(false); acl setpublicwriteaccess(false); acl setreadaccess(user objectid, true); acl setwriteaccess(user objectid, true); todo acl = acl; await todo saveasync(); step 4 – writing cloud code functions why cloud code? cloud code runs on back4app’s server side this is ideal for validations, triggers, or additional logic for your asp net core project you can keep sensitive processes secure and off the client example cloud function // main js example parse cloud define('calculatetextlength', async (request) => { const { text } = request params; if (!text) { throw new error('no text provided'); } return { length text length }; }); deployment deploy cloud code via back4app cli b4a deploy dashboard paste code into cloud code > functions and click deploy calling cloud functions in net public async task\<dictionary\<string, object>> gettextlength(string text) { var parameters = new dictionary\<string, object> { { "text", text } }; var result = await parsecloud callfunctionasync\<dictionary\<string, object>>("calculatetextlength", parameters); return result; } or via rest curl x post \\ h "x parse application id your app id" \\ h "x parse rest api key your rest api key" \\ h "content type application/json" \\ d '{"text" "hello back4app"}' \\ https //parseapi back4app com/functions/calculatetextlength step 5 – configuring authentication enable user authentication asp net core can manage its own identity but if you prefer, you can offload it to parse’s user class back4app handles password hashing, rest api sessions, and other security details // sign up public async task signupuser(string username, string password, string email) { var user = new parseuser { username = username, password = password, email = email }; await user signupasync(); } // log in public async task\<parseuser> loginuser(string username, string password) { return await parseuser loginasync(username, password); } social login integrate facebook , google , or other providers if desired by configuring oauth settings in the back4app dashboard refer to social login docs https //www back4app com/docs/platform/sign in with apple step 6 – handling file storage uploading files use parsefile to upload images or documents public async task\<parsefile> uploadimage(byte\[] filebytes, string filename) { var parsefile = new parsefile(filename, filebytes); await parsefile saveasync(); return parsefile; } file security configure file uploads at app settings > security & keys , adjusting who can upload or access files this protects user data in your web application step 7 – email verification and password reset why it matters email verification ensures users own the email provided password reset is crucial for a secure user experience in your asp net core solutions enable it on back4app go to email settings in your back4app dashboard turn on enable email verification adjust the password reset template to match your branding step 8 – scheduling tasks with cloud jobs automate background tasks use cloud jobs to run recurring tasks, like deleting old data or sending reminders for example, cleanupoldtodos // main js parse cloud job('cleanupoldtodos', async (request) => { const todo = parse object extend('todo'); const query = new parse query(todo); const now = new date(); const thirty days = 30 24 60 60 1000; const cutoff = new date(now thirty days); query lessthan('createdat', cutoff); const oldtodos = await query find({ usemasterkey true }); await parse object destroyall(oldtodos, { usemasterkey true }); return `deleted ${oldtodos length} old todos `; }); set the schedule under server settings > background jobs in the back4app dashboard step 9 – integrating webhooks using webhooks webhooks let your asp net core backend call external services whenever data changes for instance, notify a slack channel when a new todo is created navigate to webhooks under more > webhooks add a new endpoint choose the event (e g , create todo ) step 10 – exploring the back4app admin panel overview the back4app admin app helps non technical users manage data (crud) without accessing code it’s model centric and straightforward enable it under app dashboard > more > admin app > enable admin app create an admin user and pick a subdomain then log in with your new credentials with admin app, you and your team can handle essential data tasks quickly, boosting collaboration and freeing development time conclusion you’ve learned how to build a backend for asp net core using back4app to streamline data, security, and functionality by combining an open source platform with your net core skills, you now have a scalable database structure with acls and clps real time live queries for instant data updates cloud code for secure server side logic integrated web api endpoints for your web development flow automated cloud jobs and webhooks to extend your backend an easy to use admin panel for managing data with these foundations in place, you can develop full fledged asp net core applications that deliver top notch user experiences and handle large scale traffic effortlessly next steps go production harden security rules, optimize performance, and leverage back4app analytics add advanced features experiment with roles, role based access, or 3rd party apis (e g , stripe, slack) dive deeper into cloud code write custom triggers, integrate with external services, or handle complex workflows review official back4app docs back4app documentation https //www back4app com/docs/ offers guidance on advanced usage expand your asp net core project with richer mvc patterns, microservices, or specialized authentication flows