Spring WebFlux

Spring WebFlux is a fully non-blocking, reactive-stack web framework built into Spring Framework 5.0+. It enables building highly scalable, asynchronous web applications using the Reactive Streams API with Project Reactor. WebFlux supports annotated controllers, functional routing endpoints, WebSocket communication, RSocket protocol, and a powerful reactive HTTP client (WebClient) for consuming APIs.

Spring WebFlux publishes 1 API on the APIs.io network: WebSocket. Tagged areas include Java, Microservices, Non-Blocking IO, Reactive Programming, and REST API.

The Spring WebFlux catalog on APIs.io includes 1 event-driven AsyncAPI specification, 1 JSON-LD context, and 2 Spectral governance rulesets.

Spring WebFlux’s developer surface includes engineering blog, support, Stack Overflow tag, YouTube channel, release notes, changelog, and 11 more developer resources.

📡 Source on GitHub

45.3/100 developing ▬ flat Agent 17/100 agent aware self hosted · Apache-2.0 Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemium

8 APIs

Java MicroservicesNon-Blocking IOReactive ProgrammingREST API Spring Boot Spring Framework WebFlux

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 45.3/100 · developing

Contract Quality 13.6 / 23

Developer Ergonomics 6.4 / 18

Access Clarity 2.8 / 18

Operational Transparency 4.3 / 12

Contract Governance 3.1 / 11

Discoverability 5.0 / 9

Open Source Surface 10.0 / 10

Agent readiness — 17/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 90 points between them, because the conditional facet above carries the other 10. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 90% 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/webflux: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 8

Individual APIs this provider publishes, each with its own machine-readable definition.

Spring WebFlux Core

Reactive web framework providing annotated controllers, functional endpoints, dispatcher handler, and the full reactive request/response processing pipeline. Supports non-blocki...

Spring WebFlux WebClient

Reactive, non-blocking HTTP client for consuming REST services and other APIs. Supports builder-based configuration, request/response filters, error handling, streaming, and bri...

Spring WebFlux Router Functions

Functional programming model for routing and request handling in WebFlux. RouterFunction and HandlerFunction provide a lightweight, lambda-based alternative to annotated control...

Spring WebFlux WebSocket

Reactive WebSocket support for full-duplex, bidirectional communication in WebFlux applications. Provides WebSocketHandler, WebSocketSession, and integration with STOMP messagin...

Spring WebFlux RSocket

Integration with RSocket binary protocol for reactive, message-driven communication between microservices. Supports request-response, request-stream, fire-and-forget, and channe...

Reactor Core

Project Reactor is the foundational reactive library powering Spring WebFlux. Provides Mono (0-1 element) and Flux (0-N element) publisher types implementing the Reactive Stream...

Spring WebFlux HTTP Service Client

Declarative HTTP service interface client allowing annotation-based HTTP client definitions with @HttpExchange. Simplifies HTTP client creation with generated proxies backed by ...

Spring WebFlux Testing

Testing support for WebFlux applications including WebTestClient for integration testing of server endpoints, controller tests, and end-to-end testing with a full Spring applica...

Scroll for all 8

Pricing Plans 1

Published pricing tiers and plan structures.

Webflux Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Webflux Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Webflux Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Spring WebFlux WebSocket API

AsyncAPI specification describing WebSocket communication patterns for Spring WebFlux applications. Spring WebFlux provides reactive WebSocket support via WebSocketHandler and W...

ASYNCAPI

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Webflux Context

0 classes · 24 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

Spring WebFlux API Rules

5 rules · 4 warnings 1 info

SPECTRAL

Spring WebFlux API Rules

5 rules · 3 warnings 2 info

SPECTRAL

JSON Schema 3

Standalone JSON Schema definitions for this provider's data models.

Spring WebFlux Router Function Configuration

3 properties

JSON SCHEMA

Spring WebFlux WebClient Request

10 properties

JSON SCHEMA

Spring WebFlux WebClient Response

6 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Webflux Webclient Request Structure

0 properties

JSON STRUCTURE

Examples 2

Example request and response payloads for these APIs.

Webflux Webclient Get Example

5 fields

EXAMPLE

Webflux Webclient Post Example

5 fields

EXAMPLE

Resources

Documentation 1

Reference material describing how the API behaves

ContributionGuide

ContributionGuide

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

JSONLD

JSONLD

Vocabulary

Vocabulary

Build 2

SDKs, sample code, and the tooling you integrate with

CodeOfConduct

CodeOfConduct

GitHubOrganization

GitHubOrganization

Access & Security 1

Authentication, authorization, and security posture

SecurityPolicy

SecurityPolicy

Learn 1

Tutorials, courses, talks, and written guidance

YouTube

YouTube

Operate 6

Status, limits, changes, and where to get help

IssueTracker

Support

Community

StackOverflow

ReleaseNotes

ChangeLog

Commercial 1

Pricing, plans, and the legal terms of use

License

License

Company 2

The organization behind the API

Blog

Blog

Twitter

Twitter

Other 1

Properties that don't map to a standard resource type

Maven Repository

Maven Repository

Source (apis.yml)

aid: webflux
name: Spring WebFlux
description: Spring WebFlux is a fully non-blocking, reactive-stack web framework built into Spring Framework 5.0+. It enables
  building highly scalable, asynchronous web applications using the Reactive Streams API with Project Reactor. WebFlux supports
  annotated controllers, functional routing endpoints, WebSocket communication, RSocket protocol, and a powerful reactive
  HTTP client (WebClient) for consuming APIs.
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://spring.io/img/projects/spring-framework.svg
created: '2024-01-01'
modified: '2026-05-03'
specificationVersion: '0.23'
url: https://raw.githubusercontent.com/api-evangelist/webflux/refs/heads/main/apis.yml
apis:
- name: Spring WebFlux Core
  description: Reactive web framework providing annotated controllers, functional endpoints, dispatcher handler, and the full
    reactive request/response processing pipeline. Supports non-blocking I/O with Reactor Mono and Flux types.
  image: https://spring.io/img/projects/spring-framework.svg
  humanUrl: https://docs.spring.io/spring-framework/reference/web/webflux.html
  baseUrl: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/reactive/
  tags:
  - Annotated Controllers
  - Dispatcher Handler
  - Functional Endpoints
  - Non-Blocking
  - Reactive
  - Spring Framework
  - WebFlux
  properties:
  - type: Documentation
    url: https://docs.spring.io/spring-framework/reference/web/webflux.html
  - type: APIReference
    url: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/reactive/package-summary.html
  - type: GitHubRepository
    url: https://github.com/spring-projects/spring-framework/tree/main/spring-webflux
  - type: GettingStarted
    url: https://spring.io/guides/gs/reactive-rest-service/
  - type: Maven Repository
    url: https://mvnrepository.com/artifact/org.springframework/spring-webflux
- name: Spring WebFlux WebClient
  description: Reactive, non-blocking HTTP client for consuming REST services and other APIs. Supports builder-based configuration,
    request/response filters, error handling, streaming, and bridging to blocking operations. Replaces the deprecated RestTemplate.
  image: https://spring.io/img/projects/spring-framework.svg
  humanUrl: https://docs.spring.io/spring-framework/reference/web/webflux-webclient.html
  tags:
  - HTTP Client
  - Non-Blocking
  - Reactive
  - REST
  - Web-Client
  tags_raw:
  - HTTP Client
  - Non-Blocking
  - Reactive
  - REST
  - WebClient
  properties:
  - type: Documentation
    url: https://docs.spring.io/spring-framework/reference/web/webflux-webclient.html
  - type: APIReference
    url: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/reactive/function/client/WebClient.html
  - type: Tutorial
    url: https://www.baeldung.com/spring-5-webclient
  - type: GitHubRepository
    url: https://github.com/spring-projects/spring-framework/tree/main/spring-webflux
  - type: JSONSchema
    url: json-schema/webflux-webclient-request-schema.json
  - type: JSONSchema
    url: json-schema/webflux-webclient-response-schema.json
  - type: JSONStructure
    url: json-structure/webflux-webclient-request-structure.json
- name: Spring WebFlux Router Functions
  description: Functional programming model for routing and request handling in WebFlux. RouterFunction and HandlerFunction
    provide a lightweight, lambda-based alternative to annotated controllers for defining HTTP endpoints.
  humanUrl: https://docs.spring.io/spring-framework/reference/web/webflux-functional.html
  tags:
  - Functional Programming
  - Handler Functions
  - Reactive
  - Router Functions
  - Routing
  properties:
  - type: Documentation
    url: https://docs.spring.io/spring-framework/reference/web/webflux-functional.html
  - type: Code Examples
    url: https://github.com/spring-projects/spring-framework/tree/main/spring-webflux/src/test/java/org/springframework/web/reactive/function
  - type: JSONSchema
    url: json-schema/webflux-router-function-schema.json
- name: Spring WebFlux WebSocket
  description: Reactive WebSocket support for full-duplex, bidirectional communication in WebFlux applications. Provides WebSocketHandler,
    WebSocketSession, and integration with STOMP messaging protocol.
  humanUrl: https://docs.spring.io/spring-framework/reference/web/webflux-websocket.html
  tags:
  - Bidirectional
  - Full Duplex
  - Messaging
  - Real-Time
  - WebSocket
  properties:
  - type: Documentation
    url: https://docs.spring.io/spring-framework/reference/web/webflux-websocket.html
  - type: Code Examples
    url: https://spring.io/guides/gs/messaging-stomp-websocket/
  - type: AsyncAPI
    url: asyncapi/webflux-websocket-asyncapi.yml
- name: Spring WebFlux RSocket
  description: Integration with RSocket binary protocol for reactive, message-driven communication between microservices.
    Supports request-response, request-stream, fire-and-forget, and channel interaction models.
  humanUrl: https://docs.spring.io/spring-framework/reference/rsocket.html
  tags:
  - Binary Protocol
  - Microservices
  - Reactive
  - RSocket
  - Streaming
  properties:
  - type: Documentation
    url: https://docs.spring.io/spring-framework/reference/rsocket.html
  - type: APIReference
    url: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/messaging/rsocket/package-summary.html
- name: Reactor Core
  description: Project Reactor is the foundational reactive library powering Spring WebFlux. Provides Mono (0-1 element) and
    Flux (0-N element) publisher types implementing the Reactive Streams specification with composable operators.
  humanUrl: https://projectreactor.io/
  baseUrl: https://repo1.maven.org/maven2/io/projectreactor/reactor-core/
  tags:
  - Flux
  - Mono
  - Project Reactor
  - Reactive Streams
  - Reactor
  properties:
  - type: Documentation
    url: https://projectreactor.io/docs/core/release/reference/
  - type: APIReference
    url: https://projectreactor.io/docs/core/release/api/
  - type: GitHubRepository
    url: https://github.com/reactor/reactor-core
  - type: Learning Materials
    url: https://projectreactor.io/learn
  - type: Maven Repository
    url: https://mvnrepository.com/artifact/io.projectreactor/reactor-core
- name: Spring WebFlux HTTP Service Client
  description: Declarative HTTP service interface client allowing annotation-based HTTP client definitions with @HttpExchange.
    Simplifies HTTP client creation with generated proxies backed by WebClient.
  humanUrl: https://docs.spring.io/spring-framework/reference/integration/rest-clients.html#rest-http-interface
  tags:
  - Declarative
  - HTTP Client
  - HTTP Interface
  - Reactive
  - REST
  properties:
  - type: Documentation
    url: https://docs.spring.io/spring-framework/reference/integration/rest-clients.html#rest-http-interface
- name: Spring WebFlux Testing
  description: Testing support for WebFlux applications including WebTestClient for integration testing of server endpoints,
    controller tests, and end-to-end testing with a full Spring application context.
  humanUrl: https://docs.spring.io/spring-framework/reference/testing/webtestclient.html
  tags:
  - Integration Testing
  - Reactive Testing
  - Spring Boot Test
  - Testing
  - WebTestClient
  properties:
  - type: Documentation
    url: https://docs.spring.io/spring-framework/reference/testing/webtestclient.html
  - type: APIReference
    url: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/test/web/reactive/server/WebTestClient.html
common:
- type: IssueTracker
  url: https://github.com/spring-projects/spring-framework/issues
- type: SecurityPolicy
  url: https://github.com/spring-projects/spring-framework/blob/main/SECURITY.md
- type: CodeOfConduct
  url: https://github.com/spring-projects/.github/blob/main/CODE_OF_CONDUCT.md
- type: ContributionGuide
  url: https://github.com/spring-projects/spring-framework/blob/main/CONTRIBUTING.md
- type: License
  name: Apache-2.0
  url: https://github.com/spring-projects/spring-framework/blob/main/LICENSE
- type: Blog
  url: https://spring.io/blog/category/engineering
- type: Support
  url: https://spring.io/support
- type: Community
  url: https://spring.io/community
- type: StackOverflow
  url: https://stackoverflow.com/questions/tagged/spring-webflux
- type: GitHubOrganization
  url: https://github.com/spring-projects
- type: Twitter
  url: https://twitter.com/springcentral
- type: YouTube
  url: https://www.youtube.com/user/SpringSourceDev
- type: Maven Repository
  url: https://mvnrepository.com/artifact/org.springframework/spring-webflux
- type: ReleaseNotes
  url: https://github.com/spring-projects/spring-framework/releases
- type: ChangeLog
  url: https://github.com/spring-projects/spring-framework/wiki/Spring-Framework-Versions
- type: JSONLD
  url: json-ld/webflux-context.jsonld
- type: Vocabulary
  url: vocabulary/webflux-vocabulary.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
tags:
- Java
- Microservices
- Non-Blocking IO
- Reactive Programming
- REST API
- Spring Boot
- Spring Framework
- WebFlux

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