Fusio is an open source API management platform that covers the full API lifecycle, from creation and documentation through access control, rate limiting, and monetization, without requiring a commercial API gateway subscription.
The Problem
Building and operating APIs at scale requires more than writing endpoints. You need access control, rate limiting, versioning, documentation, a developer portal for external consumers, and ideally a way to charge for API access. Most teams stitch this together from multiple tools or pay for a managed API gateway that charges per request or per seat.
How Fusio Solves It
Fusio provides a single self-hosted platform covering the complete API management lifecycle. Create and document APIs, secure them with OAuth 2.0, apply rate limits per consumer, publish a developer portal for external users to discover and access your APIs, and add monetization to charge for API access. AGPL-3.0 license applies; a commercial license is available for proprietary deployments.
Key Features
- Full API lifecycle management: creation, versioning, access control, and retirement in one platform
- Built-in OAuth 2.0 authentication, rate limiting, and consumer management
- Developer portal for publishing API documentation and managing API key distribution
- API monetization layer to charge for access, built in without a third-party billing tool
- Auto-generated SDKs for popular programming languages
- Support for REST, RPC, and GraphQL API styles
Who It's For
Fusio is best for developers and product teams building APIs as an external product or service, particularly those who want a self-hosted alternative to managed API gateways with built-in monetization, without paying per-request pricing or managing separate billing infrastructure.
Compared to Kong
Unlike Kong, which focuses on proxying and transforming existing API traffic as a gateway layer, Fusio is designed for building APIs from the ground up with documentation, a developer portal, and monetization built in. Kong is a gateway; Fusio is a full API development and management platform.
