Authorizer
Your users belong in your own database - Authorizer, an open-source authentication and authorization server shipping as a single Go binary, keeps them there. It connects to 13+ backends - PostgreSQL, MySQL, SQLite, SQL Server, MariaDB, MongoDB, Cassandra, ScyllaDB, ArangoDB, DynamoDB, Couchbase, YugabyteDB, PlanetScale, and CockroachDB - so identity data lives beside the application it protects instead of in an auth vendor's cloud. The server is fully OAuth 2.0 and OpenID Connect compliant, including authorization code flow with PKCE, a JWKS endpoint, token revocation, and nine JWT signing algorithms. Login options cover email/password, magic links, TOTP multi-factor, SMS OTP via Twilio, and social providers including Google, GitHub, Apple, Microsoft, and Discord. Authorization goes beyond roles: an embedded OpenFGA engine provides Zanzibar-style relationship-based permission checks in process. APIs are exposed over GraphQL, REST, and gRPC, with SDKs for JavaScript, React, Go, and Python, plus themeable built-in login pages and an admin dashboard. Apache 2.0 licensed.
APITable
With over 15,000 GitHub stars and positioning itself as the most feature-complete open-source alternative to Airtable, APITable combines a buttery-smooth spreadsheet interface with a full database engine and automatic API generation that turns every datasheet into a queryable REST endpoint without writing a single line of backend code. Real-time collaborative editing powered by Operational Transformation algorithms supports 100,000+ rows with multiple simultaneous users, while seven built-in view types — Grid, Kanban, Gallery, Gantt chart, Calendar, Mindmap, and Form — let teams visualize the same data in whatever format suits their workflow. The one-click API panel exposes every table as a documented REST API with filtering, sorting, and pagination, effectively functioning as a backend-as-a-service for frontend developers and automation builders. Robot automation triggers workflows on record changes with integrations into n8n, Zapier, Appsmith, and Slack, while the extensible widget system provides 20+ open-source widgets for custom charts, dashboards, and data visualizations embedded directly into datasheets. Enterprise features include SAML single sign-on, field-level and row-level permissions via Mirrors, organizational team management, audit logging, database auto-backup, and data export. Bi-directional table linking with infinite cross-links creates relational data models across workspaces, and built-in templates cover CRM, project management, inventory, and content planning. 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 licensed.
Parse Server
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.
Cerbos
Cerbos decouples authorization logic from application code entirely, evaluating human-readable YAML policies in under one millisecond through a stateless Policy Decision Point that requires no application state synchronization or cross-network fan-out. Its custom decision engine benchmarks up to 17x faster than OPA-based alternatives. Access control policies use conditions expressed in Google's Common Expression Language, supporting role-based, attribute-based, and policy-based access control patterns including derived roles, scoped policies, and permissions-aware data filtering that pushes authorization predicates directly into database queries. The PDP exposes both gRPC and HTTP APIs with SDKs for JavaScript, Python, Go, Java, .NET, Rust, PHP, and Ruby, making integration a single function call regardless of tech stack. GitOps-native workflows treat policies as code with Git versioning, CI validation through GitHub Actions, coverage reports, breaking-change detection, and audit logs of every authorization decision for ISO27001, SOC2, and HIPAA compliance. Deployment flexibility spans Kubernetes sidecars, standalone services, systemd daemons, AWS Lambda functions, and WebAssembly-embedded PDPs that run authorization logic directly in browsers, serverless architectures, and edge devices. The Admin API manages policy lifecycle operations programmatically, while the built-in Playground and REPL provide interactive testing environments for policy authoring and debugging. 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.
Unkey
Unkey is the open-source platform that unifies API key management, rate limiting, deployment, and observability into a single control plane. The Go API service validates keys with sub-millisecond latency using regional Redis caches and MySQL 8.0 persistent storage, while ClickHouse captures every verification event for per-key and per-keyspace analytics with filterable time-series charts, request counters, and active key tracking. Keyspaces organize API keys by product, environment, or tier, each configurable with custom prefixes, byte lengths, IP whitelists, encrypted key recovery, and delete protection. Per-key settings include expiration dates, rate limit quotas with configurable windows, RBAC roles and permissions, owner identities linking multiple keys to a single user or organization, and key rotation with grace periods from immediate revocation through 24-hour overlap. The deployment pipeline connects GitHub repositories for automatic Docker container builds, generates preview environments per commit, promotes tested versions to production, and validates releases with OpenAPI diff detection flagging breaking changes before production. The edge gateway authenticates and rate-limits requests at the closest region before routing to the nearest API instance. Immutable audit logs track every key creation, verification, deletion, and configuration change with actor, timestamp, and event metadata. The CLI provides terminal access to key management, analytics queries, and deployment operations. On RepoCloud, deploy Unkey on a dedicated VPS with Docker, root SSH access, and complete control over your API infrastructure, all under the AGPL license.
Posta
Built as a developer-first alternative to SendGrid, Mailgun, and Postmark, Posta delivers a complete self-hosted email infrastructure platform handling both outbound delivery and inbound reception through a single HTTP API with official SDKs for Go, PHP, and Java. The Go backend processes email through Redis and Asynq with automatic retries, priority queues, and async delivery while PostgreSQL stores templates, contacts, campaigns, and delivery analytics. Outbound features include versioned multi-language templates with variable substitution and stylesheet inlining, bulk campaigns with subscriber targeting and A/B testing per-variant metrics, scheduled timezone-aware delivery with draft/paused/cancelled lifecycle states, email address verification checking syntax, MX records, disposable domains, and role accounts, plus web view links with signed expiring URLs and one-click unsubscribe headers. The built-in SMTP receiver with TLS handles inbound email at your domains, parses messages and attachments, scores spam, and forwards structured payloads to your application via HMAC-verified webhooks with real-time SSE notification streams. The Vue-based dashboard manages templates, SMTP server pools, domains, contacts, API keys, campaigns, and email logs with dark and light mode support while admin-level platform metrics expose delivery rate trends, bounce rate graphs, and latency percentiles alongside Prometheus integration and daily health reports. Deploy via Docker with PostgreSQL and Redis. 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.
JobSpy API
JobSpy API turns seven major job boards into a single REST endpoint, aggregating listings from LinkedIn, Indeed, Glassdoor, Google Jobs, ZipRecruiter, Bayt, and Naukri through one GET request. Built on FastAPI with the Python JobSpy scraping library, the API returns structured JSON or downloadable CSV containing job titles, companies, locations, salaries, descriptions, posting dates, and direct application URLs. Filters cover search terms, location, distance radius, job type (full-time, part-time, contract, internship), remote status, hours since posting, country, and salary range. Interactive Swagger UI and ReDoc interfaces provide try-it-now functionality for testing queries directly in the browser. Security includes x-api-key header authentication with configurable rotation, per-endpoint rate limiting with adjustable thresholds, and response caching with configurable TTL to reduce redundant scraping. Global proxy support routes outbound requests through HTTP/HTTPS proxies to avoid IP-based rate limiting from job boards. Environment variables control everything from default search parameters and logging levels to CORS origins and documentation paths. Health check and ping endpoints integrate with uptime monitoring services. Docker Compose exposes the API on a configurable port. MIT licensed.
Ntfy
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.
Kuzzle
Kuzzle ships a production-ready backend from day one: data storage with Elasticsearch search, real-time pub/sub notifications, user authentication, role-based permissions, and a multi-protocol API serving HTTP, WebSocket, and MQTT simultaneously on port 7512. Rather than rebuilding these standard features from scratch for each project, you get a ready-made backend that accepts connections from web applications, mobile clients, and IoT devices through one unified API surface. Elasticsearch provides persistent document storage with full-text search, geospatial queries, and aggregation pipelines, while Redis handles internal caching and memory storage operations. The Koncorde real-time engine powers pub/sub messaging and database notifications, enabling clients to subscribe to document changes with filter conditions that trigger instant updates when matching data is created, modified, or deleted. User management includes JWT-based authentication, role-based access control with granular permissions at the controller and action level, and pluggable authentication strategies via Passport.js. The extensible plugin framework allows developing custom business logic, additional authentication providers, storage connectors, and protocol handlers. Client SDKs for JavaScript, Dart, Kotlin, and C++ accelerate frontend development, while the Kourou CLI provides command-line API access and project scaffolding. The Vue.js Admin Console offers a web interface for managing indexes, collections, documents, users, profiles, and roles. Horizontal scaling through masterless cluster mode targets 99.99% uptime without single points of failure. 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.