Base44 Coder
Build apps on the Base44 platform using the Base44 JavaScript SDK.
⚡ IMMEDIATE ACTION REQUIRED - Read This First
This skill activates on ANY mention of "base44" or when a base44/ folder exists. DO NOT read documentation files or search the web before acting.
Your first action MUST be:
Check if base44/config.jsonc exists in the current directory If YES (existing project scenario): This skill (base44-sdk) handles the request Implement features using Base44 SDK Do NOT use base44-cli unless user explicitly requests CLI commands If NO (new project scenario): Transfer to base44-cli skill for project initialization This skill cannot help until project is initialized When to Use This Skill vs base44-cli
Use base44-sdk when:
Building features in an EXISTING Base44 project base44/config.jsonc already exists in the project Base44 SDK imports are present (@base44/sdk) Writing JavaScript/TypeScript code using Base44 SDK modules Implementing functionality, components, or features User mentions: "implement", "build a feature", "add functionality", "write code for" User says "create a [type] app" and a Base44 project already exists
DO NOT USE base44-sdk for:
❌ Initializing new Base44 projects (use base44-cli instead) ❌ Empty directories without Base44 configuration ❌ When user says "create a new Base44 project/app/site" and no project exists ❌ CLI commands like npx base44 create, npx base44 deploy, npx base44 login (use base44-cli)
Skill Dependencies:
base44-sdk assumes a Base44 project is already initialized base44-cli is a prerequisite for base44-sdk in new projects If user wants to "create an app" and no Base44 project exists, use base44-cli first
State Check Logic: Before selecting this skill, verify:
IF (user mentions "create/build app" OR "make a project"): IF (directory is empty OR no base44/config.jsonc exists): → Use base44-cli (project initialization needed) ELSE: → Use base44-sdk (project exists, build features) Quick Start // In Base44-generated apps, base44 client is pre-configured and available
// CRUD operations const task = await base44.entities.Task.create({ title: "New task", status: "pending" }); const tasks = await base44.entities.Task.list(); await base44.entities.Task.update(task.id, { status: "done" });
// Get current user const user = await base44.auth.me();
// External apps import { createClient } from "@base44/sdk";
// IMPORTANT: Use 'appId' (NOT 'clientId' or 'id') const base44 = createClient({ appId: "your-app-id" }); await base44.auth.loginViaEmailPassword("user@example.com", "password");
SDK Modules Module Purpose Reference entities CRUD operations on data models entities.md auth Login, register, user management auth.md agents AI conversations and messages base44-agents.md functions Backend function invocation functions.md integrations AI, email, file uploads, custom APIs integrations.md connectors OAuth tokens (service role only) connectors.md analytics Track custom events and user activity analytics.md appLogs Log user activity in app app-logs.md users Invite users to the app users.md
For client setup and authentication modes, see client.md.
TypeScript Support: Each reference file includes a "Type Definitions" section with TypeScript interfaces and types for the module's methods, parameters, and return values.
Installation
Install the Base44 SDK:
npm install @base44/sdk
Important: Never assume or hardcode the @base44/sdk package version. Always install without a version specifier to get the latest version.
Creating a Client (External Apps)
When creating a client in external apps, ALWAYS use appId as the parameter name:
import { createClient } from "@base44/sdk";
// ✅ CORRECT const base44 = createClient({ appId: "your-app-id" });
// ❌ WRONG - Do NOT use these: // const base44 = createClient({ clientId: "your-app-id" }); // WRONG // const base44 = createClient({ id: "your-app-id" }); // WRONG
Required parameter: appId (string) - Your Base44 application ID
Optional parameters:
token (string) - Pre-authenticated user token options (object) - Configuration options options.onError (function) - Global error handler
Example with error handler:
const base44 = createClient({ appId: "your-app-id", options: { onError: (error) => { console.error("Base44 error:", error); } } });
Module Selection
Working with app data?
Create/read/update/delete records → entities Import data from file → entities.importEntities() Realtime updates → entities.EntityName.subscribe()
User management?
Login/register/logout → auth Get current user → auth.me() Update user profile → auth.updateMe() Invite users → users.inviteUser()
AI features?
Chat with AI agents → agents Create new conversation → agents.createConversation() Manage conversations → agents.getConversations() Generate text/JSON with AI → integrations.Core.InvokeLLM() Generate images → integrations.Core.GenerateImage()
Custom backend logic?
Run server-side code → functions.invoke() Need admin access → base44.asServiceRole.functions.invoke()
External services?
Send emails → integrations.Core.SendEmail() Upload files → integrations.Core.UploadFile() Custom APIs → integrations.custom.call() OAuth tokens (Google, Slack) → connectors (backend only)
Tracking and analytics?
Track custom events → analytics.track() Log page views/activity → appLogs.logUserInApp() Common Patterns Filter and Sort Data const pendingTasks = await base44.entities.Task.filter( { status: "pending", assignedTo: userId }, // query "-created_date", // sort (descending) 10, // limit 0 // skip );
Protected Routes (check auth) const user = await base44.auth.me(); if (!user) { base44.auth.redirectToLogin(window.location.href); return; }
Backend Function Call // Frontend const result = await base44.functions.invoke("processOrder", { orderId: "123", action: "ship" });
// Backend function (Deno) import { createClientFromRequest } from "@base44/sdk";
Deno.serve(async (req) => { const base44 = createClientFromRequest(req); const { orderId, action } = await req.json(); // Process with service role for admin access const order = await base44.asServiceRole.entities.Orders.get(orderId); return Response.json({ success: true }); });
Service Role Access
Use asServiceRole in backend functions for admin-level operations:
// User mode - respects permissions const myTasks = await base44.entities.Task.list();
// Service role - full access (backend only) const allTasks = await base44.asServiceRole.entities.Task.list(); const token = await base44.asServiceRole.connectors.getAccessToken("slack");
Frontend vs Backend Capability Frontend Backend entities (user's data) Yes Yes auth Yes Yes agents Yes Yes functions.invoke() Yes Yes integrations Yes Yes analytics Yes Yes appLogs Yes Yes users Yes Yes asServiceRole.* No Yes connectors No Yes
Backend functions use Deno.serve() and createClientFromRequest(req) to get a properly authenticated client.