Fusio

Fusio is a self‑hosted API management platform that lets developers expose, orchestrate, and monetize any data source or service as a modern REST API. At its core it functions as an API gateway and backend‑as‑a‑service layer, while also providing a developer portal and analytics dashboard. The application is built around PHP 8+ and follows the Symfony ecosystem, delivering a modular architecture that can be extended via plugins or custom “apps” written in PHP. Its design focuses on speed, flexibility, and zero‑vendor lock‑in, making it suitable for both small prototypes and enterprise‑grade deployments.

Architecture & Technical Stack

• Language & Framework: PHP 8, Symfony components (Console, Config, HttpKernel), Doctrine ORM for persistence.
• Database: Supports MySQL/MariaDB, PostgreSQL, SQLite, and any PDO‑compatible driver.
• Routing & API Layer: Uses Symfony’s routing component to map API endpoints, with built‑in support for OAuth2, API key, and JWT authentication.
• Plugin System: “Apps” are Symfony bundles that can be installed via the marketplace or manually. They register routes, services, and admin UI panels, allowing developers to add new capabilities (e.g., a database gateway or an AI‑powered MCP integration) without touching core code.
• Event Bus & Hooks: Fusio exposes a rich event system; developers can attach listeners to lifecycle events (request received, response sent, quota exceeded) or create custom webhooks that trigger external workflows.
• SDK Generation: The OpenAPI 3 schema generated for each API can be consumed by the SDK generator service to produce ready‑to‑use clients in PHP, TypeScript, Python, and more.

Core Capabilities

• Database API Gateway – Translate SQL queries into REST endpoints with automatic pagination, filtering, and sorting.
• Custom Business Logic – Define PHP “actions” that run before or after database calls, enabling domain‑specific validation and transformation.
• Microservice Orchestration – Route requests to multiple internal services, apply rate limits, and aggregate responses.
• Developer Portal – Hosted documentation, interactive playground, and automated SDK downloads for any registered API.
• Monetization & Analytics – Per‑endpoint quotas, tiered plans, billing hooks (e.g., Stripe), and real‑time usage dashboards.
• Headless CMS Backend – Expose content models as APIs, with versioning and media handling.
• MCP Integration – Leverage the Model Context Protocol for AI‑driven API access and dynamic policy enforcement.

Deployment & Infrastructure

Fusio is deliberately lightweight: a single PHP binary, the Symfony console, and a web server (Nginx/Apache or PHP‑built‑in for testing). It is fully Docker‑ready, with an official image on Docker Hub and a minimal docker-compose.yaml example that bundles MySQL. For production, it scales horizontally behind any HTTP load balancer; the stateless request handling and database‑backed session store mean multiple instances can run in parallel without additional configuration. The platform also supports CI/CD pipelines; the marketplace can be scripted, and API definitions can be versioned in Git.

Integration & Extensibility

• Apps – The marketplace hosts a growing list of community and official apps. Each app is a Symfony bundle that can be installed via CLI (bin/fusio marketplace:install <app>).
• Webhooks & Events – Expose any internal event as a webhook; conversely, subscribe to external events via the eventbus API.
• Custom Auth Providers – Implement a new authentication mechanism by extending the AuthProviderInterface.
• SDK Customization – Modify generated SDK templates or write custom generators to fit project conventions.
• API Definition Import/Export – OpenAPI 3 JSON/YAML can be imported to create or update APIs programmatically.

Developer Experience

The platform ships with comprehensive documentation, an interactive API playground, and a built‑in SDK generator. Configuration is driven by environment variables (APP_CONNECTION, FUSIO_PROJECT_KEY), making it easy to adopt in containerized or cloud environments. Community support is active on GitHub, Discord, and Twitter; the plugin ecosystem encourages sharing of reusable business logic. Because Fusio is open source (MIT license), developers can audit the code, contribute fixes, or fork for internal customization without vendor lock‑in.

Use Cases

• Legacy Database Exposure – Convert an existing MySQL schema into a secure, versioned REST API for mobile or web clients.
• Microservice Gateways – Centralize authentication, rate limiting, and logging for a fleet of internal services.
• SaaS Provider – Offer a developer portal with auto‑generated SDKs, usage analytics, and billing hooks.
• Content APIs – Build a headless CMS that serves structured content to any frontend via API.
• AI‑Enabled Services – Use MCP integration to let AI agents query APIs with fine‑grained policy control.

Advantages Over Alternatives

• Performance – Built on Symfony’s optimized HTTP kernel; minimal overhead compared to heavy API platforms.
• Flexibility – PHP gives developers a familiar language; the plugin system removes the need for custom micro‑services.
• Licensing – MIT license allows unrestricted use, modification