With over 107,000 GitHub stars and adoption by teams at Mozilla, 1Password, Peerlist, and thousands of startups, Supabase has become the most widely deployed open-source Firebase alternative — built entirely on PostgreSQL rather than a proprietary NoSQL store. Every project provisions a dedicated Postgres database with 40+ preinstalled extensions, auto-generating REST APIs via PostgREST, GraphQL via pg_graphql, and real-time change streams via an Elixir-based WebSocket engine that supports database change listeners, user presence tracking, and arbitrary broadcast messaging. Authentication covers email and password, phone OTP, magic links, and 20+ social providers including Google, GitHub, Apple, Azure, and SAML SSO, all enforced through Postgres Row Level Security policies that run inside the database itself. S3-compatible object storage delivers files through a CDN spanning 285+ cities with on-the-fly image transformations powered by imgproxy. Edge Functions run globally distributed TypeScript on the Deno runtime with Node.js compatibility and access to over two million NPM packages. The pgvector extension stores, indexes, and queries vector embeddings for AI-powered semantic search and retrieval-augmented generation workflows. Supabase Studio provides a browser-based dashboard with a table editor, SQL editor, schema visualizer, and log explorer. Official client SDKs ship for JavaScript, Python, Flutter, Swift, Kotlin, C#, Go, and Ruby. The self-hosted Docker Compose stack runs fourteen coordinated services including Kong API gateway, Supavisor connection pooler, and Logflare analytics. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

Backed by 9,200 GitHub stars and venture funding led by Nauta Capital, Nhost is the open-source Firebase alternative that replaces Google's proprietary document store with a relational PostgreSQL foundation from day one. The Hasura integration auto-generates a real-time GraphQL API with subscriptions, role-based permissions, and remote schemas from your PostgreSQL tables, while event triggers and cron triggers automate backend workflows without custom infrastructure. Authentication supports email and password, magic links, phone OTP via SMS, social OAuth providers including Google and GitHub, WebAuthn for passwordless login with Face ID, fingerprints, and YubiKeys, plus two-factor authentication. Since the Q1 2026 release, Nhost Auth also functions as a full OAuth2 and OpenID Connect provider, allowing your Nhost project to issue tokens to third-party applications the same way GitHub or Google do. The S3-compatible storage service handles file uploads with automatic image optimization, virus scanning, and presigned URLs for secure direct downloads. Node.js serverless functions deploy JavaScript and TypeScript backend logic without managing servers, while the Nhost CLI spins up the complete local stack via Docker for development with automatic database migration tracking and Hasura metadata management. The MCP server integration exposes project documentation and data schemas to AI assistants for intelligent query building. SDKs cover JavaScript, TypeScript, React, Vue, Next.js, and Dart for Flutter. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

With 37,000 GitHub stars and over 45 million downloads powering 500,000+ deployed projects, Directus is the most widely adopted open-source backend platform that connects to your existing SQL database without requiring schema migrations or data duplication. Point it at PostgreSQL, MySQL, MariaDB, MS SQL, SQLite, OracleDB, or CockroachDB and it instantly generates production-ready REST and GraphQL APIs complete with filtering, sorting, pagination, field selection, and relational queries — all derived from your actual schema with zero configuration. The visual Studio provides a full no-code management interface where non-technical teammates create content, manage assets, build dashboards, and configure access policies without engineering involvement. Field-level granular permissions govern every API request and Studio action through composable policies applied to roles, users, and AI agents identically. A built-in AI Assistant writes copy, translates content across languages, creates records, and routes items for review directly within the Studio interface. The native Model Context Protocol server connects Claude Desktop, Cursor, ChatGPT, or any MCP-compatible tool to your live data governed by the same access policies. Real-time WebSocket subscriptions push collection changes instantly for collaborative editing and live dashboards. Extensibility covers custom endpoints, hooks, interfaces, displays, layouts, modules, and operations. Deploy via Docker with environment-variable configuration or use Directus Cloud for managed hosting. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSL-1.1 licensed with free self-hosting.

With 32,800 GitHub stars, 180 contributors, and version 3.2 shipping in July 2026, SurrealDB eliminates the database zoo by unifying document, graph, relational, time-series, geospatial, and key-value data models into a single Rust binary queried through SurrealQL — an intuitive SQL-like language that handles graph traversals, record links, subqueries, and computed fields without switching between multiple database engines. Purpose-built for AI applications, it integrates vector indexing, full-text search, and hybrid retrieval that blends semantic similarity with graph and relational intelligence for context-aware RAG pipelines and recommendation engines. Real-time subscriptions and event-driven triggers push live data changes to connected clients without requiring external message brokers like Kafka. Multi-row, multi-table ACID transactions guarantee consistency while incrementally computed views deliver pre-calculated analytics without batch processing. Role-based access control with record-level permissions, JWT authentication, and multi-tenant isolation enables backend-as-a-service usage where client applications connect directly with fine-grained security. SDKs for JavaScript, Python, Go, Rust, .NET, and Java connect via WebSocket or HTTP APIs. Storage and compute separation allows deployment as an embedded library, a single-node server, or a highly-scalable distributed cluster with TiKV or FoundationDB backends. Deploy via Docker with persistent volumes on any Linux host. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Source-available licensed.

Web analytics tools ignore native mobile, desktop, and game apps; Aptabase was built for exactly those. If Firebase Analytics would force a privacy-policy footnote you don't want to write, this is the alternative - session-based metrics with no cookies, no IDFA or GAID, no device fingerprinting, and a daily-rotated salt that makes cross-day re-identification mathematically impossible. That design means GDPR, CCPA, and PECR compliance out of the box and "Data Not Collected" App Store privacy labels without ATT prompts. The SDK coverage is the widest in its category: eleven first-party libraries spanning Swift, Kotlin, Flutter, React Native, Tauri, Electron, .NET MAUI, NativeScript, Unity, Unreal Engine, and JavaScript for web - each MIT-licensed, following platform conventions, and accepting a custom host parameter that points at your instance. Integration is minutes: initialize with an app key, call trackEvent with optional properties, and the dashboard shows sessions, events, app versions, OS breakdowns, and country-level geography. The self-hosted stack is a .NET server over PostgreSQL for metadata and ClickHouse for high-volume event ingestion, giving cloud-parity features under an AGPL license. For indie iOS/Android apps, Electron and Tauri tools, and Unity or Unreal games, it replaces Firebase without the Google entanglement.

With 12,600 GitHub stars and 52 releases in under a year of development, InsForge is the fastest-growing open-source backend platform purpose-built for AI coding agents — giving Claude, Cursor, and any MCP-compatible tool direct access to database, authentication, storage, compute, and AI model infrastructure through a single self-hosted stack. The native MCP server exposes every InsForge operation as callable tools, letting coding agents autonomously create database tables, manage user authentication, upload files, deploy edge functions, and ship complete full-stack applications without human intervention. The Model Gateway provides an OpenAI-compatible API that routes requests across multiple LLM providers (OpenAI, Anthropic, Google, and open-source models) with unified billing, rate limiting, and fallback logic. PostgreSQL with pgvector handles both relational data and vector embeddings for RAG pipelines, while S3-compatible storage manages file uploads and static assets. Edge Functions run serverless TypeScript code on Deno with sub-millisecond cold starts for API endpoints, webhooks, and scheduled tasks. The authentication system provides user management, OAuth2 flows, sessions, and magic links with JWT token handling built in. Site Deployment builds and serves frontend applications with automatic SSL and custom domain configuration. The CLI paired with Agent Skills enables terminal-based workflows where agents invoke InsForge operations directly from the command line. Deploy via Docker with PostgreSQL as the only required external dependency. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.

Backed by over 56,000 GitHub stars and a growing ecosystem of client and server SDKs covering Flutter, React Native, Swift, Kotlin, Python, Node.js, Deno, and more, Appwrite provides a complete backend platform that replaces Firebase and Supabase with a fully self-hostable architecture. The authentication module supports email and password, phone OTP, magic links, OAuth providers including Google, GitHub, Apple, and Facebook, anonymous sessions, and JWT token management with configurable session policies. The database service provides a document-oriented store with collections, indexes, query filters, pagination, and real-time subscriptions that push changes to connected clients instantly via WebSocket. The storage service handles file uploads with built-in image manipulation including cropping, resizing, format conversion, and compression, served through a CDN-ready URL structure. Serverless functions execute custom backend logic triggered by HTTP requests, scheduled cron jobs, or database events, with runtime support for Node.js, Python, PHP, Ruby, Dart, Swift, Kotlin, and Java. The messaging service enables push notifications, SMS, and email delivery through configurable providers including APNS, FCM, Twilio, Vonage, Mailgun, and Sendgrid. Team management with role-based permissions, webhook integrations, and health monitoring APIs complete the platform. The admin console provides a web-based dashboard for managing all services, monitoring usage metrics, and configuring project settings. Deployment runs via Docker Compose with MariaDB for metadata and configurable storage adapters. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSD 3-Clause licensed.

Backed by 9,000+ GitHub stars and developed by a Germany-based team with deep FIDO2 expertise, Hanko delivers the open-source authentication platform that replaces Auth0, Clerk, and Firebase Auth with a passkey-first architecture built on phishing-resistant WebAuthn credentials. The Go backend exposes both public and administrative HTTP APIs handling passkey registration and login, password authentication, email passcodes, TOTP-based MFA, security key verification, server-side sessions with remote revocation, and JWT issuing with configurable expiry and refresh policies. OAuth SSO connects Apple, Google, GitHub, Microsoft, and custom OIDC providers, while SAML Enterprise SSO integrates corporate identity providers for single sign-on across the organization. Hanko Elements provides framework-agnostic web components that embed complete onboarding, login, and user profile flows into any application with two lines of code, fully customizable via CSS variables and supporting i18n with custom translations. The JavaScript frontend SDK handles API communication, credential management, and session state for teams building custom authentication UIs without the pre-built components. Webhooks notify external services of authentication events including user creation, login, email verification, and password changes. Privacy-first design principles enforce data minimalism with user-deletable passwords and configurable identifier strategies supporting email-only, username-only, or combined approaches. Docker deployment starts the backend with PostgreSQL or MySQL, serving both APIs on configurable ports. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 (backend) / MIT (frontend) licensed.

Securing a SaaS product, running B2B onboarding, or replacing Auth0 and Keycloak with a stack they own - teams needing more than basic auth reach for ZITADEL, an open-source identity and access management platform built in Go. Its multi-tenancy model is the differentiator: a strict Instance, Organization, Project hierarchy isolates data and scopes policy at each level, with identity brokering (pre-built templates for Google, GitHub, Microsoft, Apple, plus generic OIDC, OAuth, SAML, and LDAP), domain discovery that routes users to the right organization by email domain, and delegated management so customers administer their own users and roles. Authentication covers OpenID Connect (certified, including device authorization and token exchange), SAML 2.0 as both IdP and SP, SCIM, FIDO2 passkeys for phishing-resistant passwordless login, and MFA via OTP, email, SMS, and U2F; machine-to-machine flows support JWT profile, PATs, and client credentials. The architecture is event-sourced - every mutation is an immutable event, yielding a complete audit trail - with relational projections for queries and no external session store, so it scales horizontally. API-first with gRPC and REST, extensible via Actions webhooks, and the same codebase self-hosted (Docker Compose or Helm on PostgreSQL) as in the cloud.

A PostgreSQL database becomes a production-grade GraphQL API the moment Hasura GraphQL Engine points at it: track tables and relationships - existing schemas included - and full query, mutation, and subscription types appear with where, order_by, limit, offset, and on_conflict arguments, no resolvers or boilerplate written. Its Haskell core compiles GraphQL to efficient SQL, and any query becomes a real-time live query with a single keyword, powering dashboards and collaborative UIs over standard GraphQL subscriptions. Authorization is where Hasura earns its enterprise reputation: role-based access control with row- and column-level permission policies driven by session variables from JWTs, auth webhooks, or headers - each role effectively sees its own GraphQL schema containing only what it may touch, integrating cleanly with Auth0, Firebase, or homegrown auth. Event triggers fire webhooks on inserts, updates, and deletes for asynchronous business logic; Actions extend the schema with custom REST handlers; remote schema stitching merges external GraphQL services into one endpoint; and auto-generated REST endpoints serve clients that skip GraphQL. A browser console handles data modeling and API exploration, the CLI manages migrations and metadata as code, and deployment is a single stateless Docker container beside Postgres.

Powering authentication for over 15,000 GitHub stargazers and production deployments across startups and enterprises alike, SuperTokens delivers the complete login infrastructure that Auth0, Firebase Auth, and AWS Cognito charge premium prices for — entirely open source under Apache 2.0 with no per-user limits. The Java-based core service runs as a lightweight HTTP microservice that connects to PostgreSQL or MySQL and handles email-password login, passwordless magic links and OTP via email or SMS, social OAuth with Google, GitHub, Facebook, Apple, and any custom OIDC provider, phone-password authentication, and time-based one-time password multi-factor authentication. Session management uses rotating refresh tokens with anti-CSRF and anti-session-fixation protections, verifying tokens locally in your backend SDK without network round-trips to the core. Frontend SDKs for React, React Native, Angular, Vue, and vanilla JavaScript provide pre-built UI components for login, signup, email verification, and password reset flows, all customizable through an override system that lets you add pre- and post-API logic, custom hooks, and user event handlers. The built-in user management dashboard enables administrators to view users, reset passwords, revoke sessions, modify roles, and manage email verification status. Multi-tenancy and organization support powers B2B SaaS applications with tenant-level authentication configuration and Enterprise SSO via SAML and OIDC. Migration tools support bulk importing millions of existing password hashes, TOTP secrets, and role mappings. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

Real-time alerts from your own infrastructure to your phone, with no Firebase, Pushover, or third-party push service in the path: Gotify is a simple, self-hosted notification server written in Go. The model is deliberately minimal: senders push messages with a single HTTP POST to the REST API, receivers subscribe over a WebSocket stream, and a clean React web UI manages the pieces. Senders are namespaced as "applications," each with its own token, so your backup script, Uptime Kuma, CI pipeline, and cron jobs each get an identity, an icon, and independently revocable credentials - centralized alerting from many services with per-source management. Messages carry a title, body, and priority level that maps to notification importance on the client. The official Android app (on both F-Droid and Google Play, notable for working entirely without Google Play Services) shows push notifications for new messages; the web UI itself supports Web Push in the browser; and gotify/cli pushes messages from shell scripts with one command. A server-side plugin system adds custom behavior, and the whole thing runs as a single small binary with SQLite by default - near-zero resource footprint. Because dozens of tools (and Apprise) speak Gotify natively, it slots in as the notification hub for an entire homelab or ops stack.

With 21,400 GitHub stars, 500+ contributors, and battle-tested since its 2016 open-source release after powering Facebook's mobile backend infrastructure, Parse Server delivers production-grade Backend-as-a-Service that eliminates months of custom API development. The platform generates REST and GraphQL endpoints automatically from your data schema with class-level permissions and object-level ACLs providing granular access control. Cloud Code enables server-side JavaScript execution for triggers (beforeSave, afterSave, beforeDelete, afterDelete), custom functions, and scheduled jobs — all deployable without restarting the server. Live Queries push realtime data changes to subscribed clients via WebSockets, powering chat applications, collaborative editors, and live dashboards. Push notification support spans APNs for iOS, FCM for Android, and web push for browsers with audience segmentation, scheduling, and delivery analytics. The Parse Dashboard provides a comprehensive admin interface with a data browser featuring configurable info panels, graph visualization, custom canvas builder with draggable elements, AI agent integration via OpenAI, data import/export, and multi-factor authentication. Database flexibility supports MongoDB 6-8 and PostgreSQL 13-18 with PostGIS for geospatial queries. Native SDKs cover JavaScript, iOS (Swift/Objective-C), Android, Flutter/Dart, .NET/Xamarin, Unity, PHP, and Arduino for IoT devices. Deploy via npm, Docker, or the official Express template with automatic schema migration. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

With 13,800 GitHub stars, adoption by OpenAI for ChatGPT's authentication infrastructure serving 800 million weekly active users, and governance under the Ory open-source ecosystem, Ory Kratos provides enterprise-grade identity management as a headless API server that separates authentication logic from user interface — enabling any frontend framework to consume standardized self-service flows for registration, login, recovery, verification, and profile management. Multi-factor authentication supports passkeys, WebAuthn security keys, TOTP authenticator apps, SMS one-time codes, email magic links, and backup recovery codes with configurable Authenticator Assurance Levels enforcing step-up authentication for sensitive operations. Social sign-in connects to any OpenID Connect provider including Google, GitHub, Apple, and Microsoft, plus enterprise SAML 2.0 federation for B2B single sign-on. Customizable identity schemas using JSON Schema define user profiles with flexible trait structures, while pre- and post-flow webhooks enable integration with CRMs, analytics, and compliance systems. The courier system handles email and SMS delivery for verification codes and password recovery links. Session management provides device tracking, forced logout, and configurable lifespans with privileged session elevation. Deploy alongside Ory Hydra for OAuth2/OIDC token issuance and Ory Keto for fine-grained permissions to build a complete identity platform. Docker Compose deployment with PostgreSQL. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

An entire backend in a single Go executable: PocketBase embeds SQLite with realtime subscriptions, authentication and user management, file storage, and an admin dashboard, all behind a REST-ish API. SQLite runs in WAL mode, which outperforms client-server databases for the read-heavy workloads typical of small and mid-sized apps. Authentication supports email/password, one-time passwords, and 15+ OAuth2 providers including Google, Apple, and GitHub, with stateless tokens. Clients subscribe to record changes over server-sent events, and official JavaScript and Dart SDKs cover web, mobile, and Flutter frontends. Collections, rules, and API access permissions are managed visually in the admin UI. When you need custom logic, extend it with JavaScript hooks running in the embedded JS VM of the prebuilt binary, or import PocketBase as a Go library and compile custom business logic into your own single-file backend. File storage attaches uploads to records with thumbnail generation for images and optional S3-compatible external storage. All state lives in one pb_data directory, so backup is a directory copy and upgrade is replacing a binary - one of the lowest-maintenance backends you can run. The contrast with Firebase is the point: where usage-based pricing scales with reads, writes, and bandwidth, PocketBase runs the entire backend at flat hosting cost, and the data is a plain SQLite file you can copy anywhere. MIT-licensed.

With 13,800+ GitHub stars and active releases through 2026, Casdoor is the open-source identity platform that ships OAuth 2.0, OIDC, SAML 2.0, CAS, LDAP, SCIM 2.0, WebAuthn passkeys, TOTP multi-factor authentication, and Face ID biometric login in a single Go binary with a React web console — covering every authentication protocol your organization will ever need. Social login connects 50+ identity providers including Google, GitHub, Microsoft Azure AD, Facebook, WeChat, DingTalk, Apple, Twitter, and LinkedIn without custom code. The AI-first architecture includes a Model Context Protocol gateway for AI agent authentication and Agent-to-Agent protocol support for securing LLM-powered workflows. Built-in Casbin integration delivers authorization primitives beyond basic RBAC: attribute-based access control, relationship-based access control, and custom policy models through a unified engine. The organization-scoped multi-tenancy model isolates users, applications, and identity providers per tenant with customizable login pages, branding, and SMTP configuration. SCIM 2.0 endpoints automate user provisioning from HR systems and Active Directory. Official SDKs for Go, Java, Node.js, Python, and PHP accelerate application integration. The RESTful API exposes every resource for programmatic management. Comprehensive audit logs record authentication events and administrative actions. Deploy via Docker Compose with MySQL or PostgreSQL, the all-in-one SQLite Docker image for quick trials, or the official Kubernetes Helm chart for production clusters. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

ntfy sends push notifications to your phone or desktop with a single curl command: publish a message to any topic and every subscriber receives it instantly, no signup or API key required. Over 31,000 GitHub stars and 106 releases since 2021 back a server supporting five priority levels mapped to distinct notification sounds and vibration patterns, emoji tags for visual classification, click actions that open URLs when tapped, and up to three action buttons per notification for view, HTTP callback, broadcast, or clipboard copy operations. File attachments push images from surveillance cameras, documents, or any binary payload directly to mobile devices. Subscriptions work through JSON streams, Server-Sent Events, WebSockets, or raw text, with server-side filtering by priority, tags, and message ID. Authentication enforces topic-level access control through Basic Auth, Bearer tokens, or query parameters, with a built-in user and ACL management system. UnifiedPush compatibility lets ntfy serve as a push distributor for Mastodon, Matrix, and other federated services. Web Push via VAPID keys delivers browser notifications without the mobile app. The server ships as a single statically linked Go binary or Docker image supporting amd64, armv7, and arm64 architectures, consuming 30-50 MB RAM at idle with SQLite-backed message caching. Integrations include Grafana, Prometheus Alertmanager, Uptime Kuma, Home Assistant, and Ansible Semaphore. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 / GPLv2 dual-licensed.

With 5,400+ GitHub stars and sub-millisecond response times that eliminate the need for dedicated caches entirely, TrailBase consolidates your database, API server, auth service, realtime subscriptions, and admin interface into a single Rust binary weighing under 40MB. The platform generates type-safe CRUD APIs automatically from your SQLite schema with configurable access control rules using SQL expressions, while realtime subscriptions push data changes to connected clients via Server-Sent Events. The embedded Wasmtime runtime executes custom server-side logic as WebAssembly components compiled from Rust, JavaScript, Python, or any language targeting WASI, enabling complex business logic without external services. First-class geospatial support through the in-house LiteGIS GEOS extension provides GeoJSON integration, spatial indexing via R-Trees, and query operators including @within, @intersects, and @contains for location-based applications. Client SDKs span JavaScript/TypeScript, Dart/Flutter, Rust, C#/.NET, Swift, Kotlin, Go, and Python — covering mobile, web, desktop, and IoT platforms. The admin dashboard offers visual schema editing, a data browser, Record API configuration, OAuth provider setup, user management, SQL query editor, ERD visualization, and server logs. Experimental PostgreSQL support (v0.28+) allows connecting to existing Postgres instances via connection string. Deploy via a single binary, Docker container, or the one-line install script across Linux, macOS, and Windows. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. OSL-3.0 licensed.