Todo App Backend Template
PHP — Schema, API & AI Guide

Key Takeaways

Overview

A Todo app is one of the most common starting points for learning backend development. Under the hood it needs user registration, task CRUD, ownership-based access control, and optionally real-time sync.

The schema below defines two classes — _User (built-in) and Todo — connected by a Pointer. With the Back4app PHP SDK, you can interact with this backend from your app — querying, creating, updating, and deleting objects — without writing a custom API layer.

Why Build Your PHP Todo Backend with Back4app?

Back4app gives PHP apps a ready backend so you can focus on Laravel or your existing stack.

• •REST integration: Use Guzzle or cURL to call Back4app REST endpoints; PSR-style code and type hints keep requests clear.
• •No database migrations: Schema lives on Back4app; add fields from the dashboard or API without touching your PHP schema layer.
• •Deployment flexibility: Run your PHP app on any host; Back4app handles auth, storage, and real-time so you deploy faster.

Ideal for Laravel or standalone PHP projects that need a managed backend.

Core Benefits

A production-ready Todo backend so you can ship faster and focus on your app.

Technical Stack

Everything powering this Todo app template at a glance.

ER Diagram

Entity-Relationship diagram for the PHP Todo app data model.

erDiagram
    _User {
        String objectId PK
        String username
        String email
        String password
        Date createdAt
        Date updatedAt
    }

    Todo {
        String objectId PK
        String title
        Boolean done
        Date dueDate
        Number priority
        Pointer owner FK
        Date createdAt
        Date updatedAt
    }

    _User ||--o{ Todo : "owns"

Integration Flow

Auth-to-CRUD sequence: how your PHP app talks to Back4app — login, then query and create todos.

sequenceDiagram
  participant User
  participant App as PHP App
  participant Back4app as Back4app REST API

  User->>App: Login
  App->>Back4app: POST /login (username, password)
  Back4app-->>App: sessionToken
  App-->>User: Logged in

  User->>App: Load todos
  App->>Back4app: GET /classes/Todo (X-Parse-Session-Token)
  Back4app-->>App: results[]
  App-->>User: Show list

  User->>App: Create todo
  App->>Back4app: POST /classes/Todo
  Back4app-->>App: objectId, createdAt
  App-->>User: Updated list

Data Dictionary

Complete field reference for every class in the schema.

Security & Permissions

How ownership, ACLs, and class-level permissions protect data in this schema.

Schema (JSON)

Raw JSON schema definition — copy and use in your Back4app app or import via the API.

{
  "classes": [
    {
      "className": "Todo",
      "fields": {
        "objectId": {
          "type": "String",
          "required": false
        },
        "title": {
          "type": "String",
          "required": true
        },
        "done": {
          "type": "Boolean",
          "required": false,
          "defaultValue": false
        },
        "dueDate": {
          "type": "Date",
          "required": false
        },
        "priority": {
          "type": "Number",
          "required": false,
          "defaultValue": 3
        },
        "owner": {
          "type": "Pointer",
          "targetClass": "_User",
          "required": false
        },
        "createdAt": {
          "type": "Date",
          "required": false
        },
        "updatedAt": {
          "type": "Date",
          "required": false
        }
      }
    },
    {
      "className": "_User",
      "fields": {
        "objectId": {
          "type": "String",
          "required": false
        },
        "username": {
          "type": "String",
          "required": true
        },
        "email": {
          "type": "String",
          "required": true
        },
        "password": {
          "type": "String",
          "required": true
        },
        "createdAt": {
          "type": "Date",
          "required": false
        },
        "updatedAt": {
          "type": "Date",
          "required": false
        }
      }
    }
  ]
}

API Playground

Try the REST and GraphQL endpoints for the Todo schema. Responses from the example data above — no Back4app account needed.

Uses the same Todo schema as this template.

Step-by-Step PHP Integration

Connect to your Back4app backend from a PHP app using the Back4app PHP SDK.

1. Step 1: Install Back4app PHP SDK

   Add the Back4app SDK for your stack (e.g. npm, pubspec, or package manager).

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   composer require guzzlehttp/guzzle

2. Step 2: Initialize Back4app in your app

   Initialize the Back4app SDK at app startup with your App ID and server URL.

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   // Initialize (e.g. bootstrap or config)
   $baseUrl = 'https://parseapi.back4app.com';
   $appId = getenv('PARSE_APP_ID');
   $restKey = getenv('PARSE_REST_KEY');
   $sessionToken = null; // set after login

3. Step 3: Query all todos

   Use the SDK to fetch all Todo objects, sorted by priority.

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   // GET /classes/Todo
   function getTodos(string $baseUrl, string $appId, string $restKey, ?string $sessionToken): array {
       $client = new \GuzzleHttp\Client();
       $headers = [
           'X-Parse-Application-Id' => $appId,
           'X-Parse-REST-API-Key'   => $restKey,
           'Content-Type' => 'application/json',
       ];
       if ($sessionToken) $headers['X-Parse-Session-Token'] = $sessionToken;
       $res = $client->get($baseUrl . '/classes/Todo?order=priority', ['headers' => $headers]);
       $body = json_decode($res->getBody()->getContents(), true);
       return $body['results'] ?? [];
   }

4. Step 4: Create a todo

   Create a new Todo with title, done, and priority, then save.

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   // POST /classes/Todo
   function createTodo(string $baseUrl, string $appId, string $restKey, string $sessionToken, string $title, int $priority = 3): array {
       $client = new \GuzzleHttp\Client();
       $res = $client->post($baseUrl . '/classes/Todo', [
           'headers' => [
               'X-Parse-Application-Id' => $appId,
               'X-Parse-REST-API-Key'   => $restKey,
               'X-Parse-Session-Token'  => $sessionToken,
               'Content-Type' => 'application/json',
           ],
           'json' => ['title' => $title, 'done' => false, 'priority' => $priority],
       ]);
       return json_decode($res->getBody()->getContents(), true);
   }

5. Step 5: Update and delete todos

   Update fields and save, or delete the object.

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   // PUT /classes/Todo/{objectId} — mark done
   // DELETE /classes/Todo/{objectId}
   function markDone(string $baseUrl, string $appId, string $restKey, string $sessionToken, string $objectId): void {
       $client = new \GuzzleHttp\Client();
       $client->put($baseUrl . '/classes/Todo/' . $objectId, [
           'headers' => [
               'X-Parse-Application-Id' => $appId,
               'X-Parse-REST-API-Key'   => $restKey,
               'X-Parse-Session-Token'  => $sessionToken,
               'Content-Type' => 'application/json',
           ],
           'json' => ['done' => true],
       ]);
   }

Frequently Asked Questions

Common questions about the Todo app backend template.