Fusio is Apache-2.0, self-hosted API management from apioo (Christoph Kappestein, Germany). An operator installs it and builds APIs inside it: an operation binds an HTTP method and path to an action (SQL, HTTP, MongoDB, Elasticsearch, an LLM agent, or code running in a JavaScript, Python, Java or PHP worker) and a TypeSchema-defined request and response shape. Every instance then generates its own machine-readable contract live - OpenAPI 3.0.3, OpenRPC 1.3.0 and TypeAPI - and serves an RFC 9727 api-catalog, RFC 8414 and RFC 9728 OAuth metadata, OpenID Connect discovery and an RFC 9116 security.txt out of the box. It ships its own OAuth2 authorization server, an Angular developer portal, a rate-limiting and monetization layer, a webhook and trigger system, and an MCP server that turns every published operation into an agent tool. There is no vendor-hosted tier and no pricing: the software is the product.
Fusio publishes 4 APIs on the APIs.io network, including Backend API, Consumer API, System API, and 1 more. Tagged areas include API Management, Open-Source, REST API, API Gateway, and Developer Portal.
The Fusio catalog on APIs.io includes 1 event-driven AsyncAPI specification.
Fusio’s developer surface includes CLI, sandbox, changelog, API reference, authentication, documentation, getting-started guide, and 39 more developer resources.
Open Source Surface applies to this provider. This product is open source and we
read its repository directly, so Open Source Surface carries
10 points of the composite. It is scored from what the repository actually
publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the
provider rather than inferred from our own catalog pointers.
This facet adds; nothing was taken away to make room for it. An open-source project is not excused from
the commercial facets, because exemption would strip it of the points it does earn.
If we have the wrong repository, or this product is not open source, say so on your
provider repo and we
will drop the facet rather than have you publish against it.
Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it
carries 10 points of the composite. It is scored from the published contracts
themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already
holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in
front of it, and the first time that check is skipped a duplicate record is created.
Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet,
not penalised by it.
The six quality facets above are damped to 80 points between them,
because the conditional facet above carries the other
20. That is why each facet's contribution is shown against a damped
maximum: raising a quality facet moves the composite by 80% of its nominal
weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/fusio: open an issue to ask a question, or submit a pull request to add artifacts.
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The Fusio Backend API provides a REST interface to configure and manage all aspects of a Fusio API management instance. It covers operations, routes, schemas, actions, connectio...
The Fusio Consumer API is used by the developer portal application and enables third-party developers to request access tokens, manage their apps, and interact with protected AP...
The Fusio Worker API enables executing API action logic in multiple programming languages by forwarding requests to external worker processes. Workers are implemented in the tar...
The Fusio System API is the meta surface every Fusio instance exposes without configuration. It carries the discovery document at the root, the health check, the route table, an...
The Fusio Authorization API is the OAuth2 authorization server Fusio ships in the product. It issues and refreshes access tokens across the authorization_code, client_credential...
Fusio ships a first-party Model Context Protocol server inside the product itself. It is not a separate package or a hosted vendor endpoint: every Fusio instance can expose its ...
aid: fusio
name: Fusio
description: 'Fusio is Apache-2.0, self-hosted API management from apioo (Christoph Kappestein, Germany). An operator installs
it and builds APIs inside it: an operation binds an HTTP method and path to an action (SQL, HTTP, MongoDB, Elasticsearch,
an LLM agent, or code running in a JavaScript, Python, Java or PHP worker) and a TypeSchema-defined request and response
shape. Every instance then generates its own machine-readable contract live - OpenAPI 3.0.3, OpenRPC 1.3.0 and TypeAPI -
and serves an RFC 9727 api-catalog, RFC 8414 and RFC 9728 OAuth metadata, OpenID Connect discovery and an RFC 9116 security.txt
out of the box. It ships its own OAuth2 authorization server, an Angular developer portal, a rate-limiting and monetization
layer, a webhook and trigger system, and an MCP server that turns every published operation into an agent tool. There is
no vendor-hosted tier and no pricing: the software is the product.'
type: Index
deliveryModel:
model: self-hosted
license: Apache-2.0
open_source: true
commercial: false
callable_host: false
label: Self-hosted open source · you run it yourself
confidence: high
source:
- license
generated: '2026-08-28'
method: derived
accessModel:
pricing: freemium
onboarding: unknown
trial: false
try_now: false
public: false
label: Freemium
confidence: medium
source:
- plans
generated: '2026-07-22'
method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/fusio.png
access: 3rd-Party
created: '2026-03-16'
modified: '2026-08-29'
position: Consuming
tags:
- API Management
- Open-Source
- REST API
- API Gateway
- Developer Portal
- OpenAPI
- Self-Hosted
- MCP
tags_raw:
- API Management
- Open Source
- REST API
- API Gateway
- Developer Portal
- OpenAPI
- Self-Hosted
- MCP
url: https://raw.githubusercontent.com/api-evangelist/fusio/refs/heads/main/apis.yml
specificationVersion: '0.23'
apis:
- aid: fusio:fusio-backend-api
name: Fusio Backend API
description: The Fusio Backend API provides a REST interface to configure and manage all aspects of a Fusio API management
instance. It covers operations, routes, schemas, actions, connections, apps, users, and marketplace resources used by
the Fusio backend application.
humanURL: https://docs.fusio-project.org/docs/backend/
baseURL: https://demo.fusio-project.org
tags:
- Backend
- Configuration
- Management
- REST API
properties:
- type: Documentation
url: https://docs.fusio-project.org/docs/backend/
- type: APIReference
url: https://demo.fusio-project.org/apps/redoc
- type: OpenAPI
url: openapi/fusio-backend.json
- type: Overlay
url: overlays/fusio-backend-overlay.yaml
- type: OpenRPC
url: typeapi/fusio-backend-openrpc.json
- type: TypeAPI
url: typeapi/fusio-backend-typeapi.json
- type: GitHubRepository
url: https://github.com/apioo/fusio
- aid: fusio:fusio-consumer-api
name: Fusio Consumer API
description: The Fusio Consumer API is used by the developer portal application and enables third-party developers to request
access tokens, manage their apps, and interact with protected API endpoints. It provides the authentication and user management
layer for API consumers.
humanURL: https://docs.fusio-project.org/docs/backend/consumer/
baseURL: https://demo.fusio-project.org
tags:
- Authentication
- Consumer
- Developer Portal
- REST API
properties:
- type: Documentation
url: https://docs.fusio-project.org/docs/backend/consumer/user/
- type: APIReference
url: https://demo.fusio-project.org/apps/redoc
- type: OpenAPI
url: openapi/fusio-consumer.json
- type: Overlay
url: overlays/fusio-consumer-overlay.yaml
- type: GitHubRepository
url: https://github.com/apioo/fusio
- aid: fusio:fusio-worker-api
name: Fusio Worker API
description: The Fusio Worker API enables executing API action logic in multiple programming languages by forwarding requests
to external worker processes. Workers are implemented in the target language (JavaScript, Python, Java, PHP, etc.) and
communicate with the Fusio core via a simple REST interface, enabling serverless deployments.
humanURL: https://docs.fusio-project.org/docs/internal/worker_api
baseURL: http://{worker_host}:9092
tags:
- Multi-Language
- REST API
- Serverless
- Worker
properties:
- type: Documentation
url: https://docs.fusio-project.org/docs/internal/worker_api
- type: GitHubRepository
url: https://github.com/apioo/fusio-worker-php
x-base-url-note: Templated on purpose. A worker is a container the operator runs alongside Fusio, so its host is theirs;
the port is the one the provider's own docker-compose publishes per language (java 9090, javascript 9091, php 9092, python
9093). This entry tracks the PHP worker.
- aid: fusio:fusio-system-api
name: Fusio System API
description: 'The Fusio System API is the meta surface every Fusio instance exposes without configuration. It carries the
discovery document at the root, the health check, the route table, and the specification generator that emits the instance''s
own OpenAPI, OpenRPC, TypeAPI and client SDK archives on demand. It is what makes a Fusio deployment self-describing:
the contract is generated from the running instance rather than maintained beside it.'
humanURL: https://docs.fusio-project.org/docs/architecture
baseURL: https://demo.fusio-project.org
tags:
- Discovery
- Health
- Meta
- OpenAPI
- REST API
properties:
- type: Documentation
url: https://docs.fusio-project.org/docs/architecture
- type: OpenAPI
url: openapi/fusio-system.json
- type: Overlay
url: overlays/fusio-system-overlay.yaml
- type: APICatalog
url: well-known/fusio-api-catalog.json
- type: GitHubRepository
url: https://github.com/apioo/fusio
- aid: fusio:fusio-authorization-api
name: Fusio Authorization API
description: The Fusio Authorization API is the OAuth2 authorization server Fusio ships in the product. It issues and refreshes
access tokens across the authorization_code, client_credentials, password and refresh_token grants, resolves the identity
behind a token, and revokes tokens. It is advertised through RFC 8414 authorization-server metadata, RFC 9728 protected-resource
metadata and an OpenID Connect discovery document served from the same instance.
humanURL: https://docs.fusio-project.org/docs/security/authorization
baseURL: https://demo.fusio-project.org
tags:
- Authorization
- Authentication
- OpenID Connect
- REST API
- Security
tags_raw:
- Authorization
- OAuth2
- OpenID Connect
- REST API
- Security
properties:
- type: Documentation
url: https://docs.fusio-project.org/docs/security/authorization
- type: OpenAPI
url: openapi/fusio-authorization.json
- type: Overlay
url: overlays/fusio-authorization-overlay.yaml
- type: Authentication
url: authentication/fusio-authentication.yml
- type: OAuthScopes
url: scopes/fusio-scopes.yml
- type: OpenIDConnect
url: well-known/fusio-openid-configuration.json
- type: GitHubRepository
url: https://github.com/apioo/fusio
common:
- type: Website
url: https://www.fusio-project.org/
- type: OpenAPI
url: openapi/fusio-backend.json
- type: MCPServer
url: mcp/fusio-mcp.yml
- type: ToolCrosswalk
url: mcp/fusio-tool-crosswalk.yml
- type: AgentSkill
url: skills/_index.yml
- type: WellKnown
url: well-known/fusio-well-known.yml
- type: APICatalog
url: well-known/fusio-api-catalog.json
- type: SecurityTxt
url: well-known/fusio-security.txt
- type: Security
url: security/fusio-vulnerability-disclosure.yml
- type: VulnerabilityDisclosure
url: security/fusio-vulnerability-disclosure.yml
- type: Conventions
url: conventions/fusio-conventions.yml
- type: ErrorCatalog
url: errors/fusio-problem-types.yml
- type: Lifecycle
url: lifecycle/fusio-lifecycle.yml
- type: Deprecation
url: lifecycle/fusio-lifecycle.yml
- type: Conformance
url: conformance/fusio-conformance.yml
- type: DataModel
url: data-model/fusio-data-model.yml
- type: Webhooks
url: asyncapi/fusio-webhooks.yml
- type: Packages
url: packages/fusio-packages.yml
- type: CLI
url: cli/fusio-cli.yml
- type: Components
url: components/fusio-components.yml
- type: Sandbox
url: sandbox/fusio-sandbox.yml
- type: LLMsTxt
url: llms/fusio-llms.txt
- type: Overlay
url: overlays/fusio-backend-overlay.yaml
- type: RateLimits
url: rate-limits/fusio-rate-limits.yml
- type: Plans
url: plans/fusio-plans-pricing.yml
- type: ChangeLog
url: changelog/fusio-changelog.yml
- type: DeveloperPortal
url: https://www.fusio-project.org/developers
- type: APIReference
url: https://demo.fusio-project.org/apps/redoc
- type: Roadmap
url: https://github.com/apioo/fusio/milestones
- type: Demo
url: https://www.fusio-project.org/demo
- type: Authentication
url: authentication/fusio-authentication.yml
- type: OAuthScopes
url: scopes/fusio-scopes.yml
- type: IssueTracker
url: https://github.com/apioo/fusio/issues
- type: Releases
url: https://github.com/apioo/fusio/releases
- type: ContributionGuide
url: https://github.com/apioo/fusio/blob/master/CONTRIBUTING.md
- type: License
name: Apache-2.0
url: https://github.com/apioo/fusio/blob/master/LICENSE
- type: DomainSecurity
url: security/fusio-domain-security.yml
- type: Documentation
url: https://docs.fusio-project.org/
- type: GettingStarted
url: https://docs.fusio-project.org/docs/bootstrap
- type: Blog
url: https://www.fusio-project.org/blog
- type: ChangeLog
url: https://github.com/apioo/fusio/blob/master/CHANGELOG.md
- type: GitHubOrganization
url: https://github.com/apioo
- type: GitHubRepository
url: https://github.com/apioo/fusio
- type: Support
url: https://discord.com/invite/eMrMgwsc6e
- type: Marketplace
url: https://www.fusio-project.org/marketplace
- type: SDKs
url: https://docs.fusio-project.org/docs/backend/development/sdk
- type: Features
data:
- name: API Gateway
description: Route and manage incoming API requests with built-in rate limiting and authentication.
- name: Developer Portal
description: Self-service developer portal for API consumers to register, browse APIs, and manage access tokens.
- name: Multi-Language Workers
description: Execute API action logic in JavaScript, Python, Java, PHP, and other languages through worker processes.
- name: Marketplace
description: Browse and install pre-built API actions and adapters from the Fusio marketplace.
- name: Schema Management
description: Define and manage API request and response schemas using TypeSchema format.
- name: OAuth2 Authentication
description: Built-in OAuth2 server for securing APIs with token-based authentication.
- name: Rate Limiting
description: Configure per-app and per-user rate limits to protect API resources.
- name: Webhook Support
description: Define webhook subscriptions to notify consumers of events.
- type: UseCases
data:
- name: API Product Building
description: Build and publish API products with documentation, authentication, and developer onboarding.
- name: Microservices Gateway
description: Use Fusio as an API gateway in front of microservices for unified access control.
- name: Data Integration
description: Connect to databases and external APIs to build data integration endpoints.
- name: Serverless API Backend
description: Build API backends that execute logic in multiple languages without managing servers.
- type: Integrations
data:
- name: MySQL and PostgreSQL
description: Connect to MySQL and PostgreSQL databases as data sources for API endpoints.
- name: MongoDB
description: Use MongoDB as a NoSQL data source for API endpoints.
- name: Elasticsearch
description: Integrate with Elasticsearch for search-powered API endpoints.
- name: RabbitMQ
description: Use RabbitMQ for asynchronous message processing in API workflows.
- name: Docker
description: Deploy Fusio and worker containers using Docker and Docker Compose.
maintainers:
- FN: Kin Lane
email: kin@apievangelist.com
x-enrichment:
date: '2026-08-29'
status: enriched
artifacts_added: 38
pass: local-v1
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