# Feign

**Canonical:** https://apis.io/providers/feign/  
**APIs profiled:** 12

Feign (OpenFeign) is a declarative Java HTTP client binder inspired by Retrofit, JAX-RS, and WebSocket. It turns annotated interfaces into templated HTTP requests with pluggable encoders, decoders, error handlers, and HTTP transports. The OpenFeign organization maintains a large set of modules covering serialization (Jackson, Gson, Moshi, FastJSON2, JAXB, SAX, SOAP), HTTP transports (OkHttp, Apache HttpClient, Java 11 client, Ribbon), JAX-RS contracts, resilience (Hystrix), logging (SLF4J), form encoding, GraphQL, and metrics.

## Kin Score — 15.0 / 100 (emerging)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 15.0).

| Facet | Score |
|---|---|
| Discoverability | 64.8 |
| Contract Quality | 0.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 26.3 |
| Developer Ergonomics | 9.5 |
| Commercial Clarity | 15.8 |
| Access Clarity | 15.8 |

## Agent readiness — 3.0 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Freemium — onboarding: unknown, pricing: freemium, trial: no (confidence: medium).

## APIs (12)

- **Feign Core** — Feign Core is the base library that processes annotated Java interfaces into templated HTTP requests. It defines the contract, encoder, decoder, and client abstractions used acr...
- **Feign Jackson** — Feign Jackson module provides Jackson-based JSON encoding and decoding for Feign-annotated client interfaces, the most common serialization choice in JVM applications.
- **Feign Gson** — Feign Gson module provides Google Gson-based JSON encoding and decoding for Feign clients, useful in projects already standardized on Gson.
- **Feign OkHttp** — Feign OkHttp module replaces the default JDK HTTP transport with Square's OkHttp client, adding HTTP/2, connection pooling, and modern transport features.
- **Feign Apache HttpClient** — Feign Apache HttpClient module integrates Apache HttpComponents (HC5) as the underlying HTTP transport for Feign clients.
- **Feign Java 11 HTTP** — Feign Java 11 HTTP module uses the JDK 11+ standard HttpClient as the transport, supporting HTTP/2 and asynchronous calls without external dependencies.
- **Feign Ribbon** — Feign Ribbon module integrates Netflix Ribbon for client-side load balancing across a list of HTTP servers.
- **Feign Hystrix** — Feign Hystrix module wraps Feign client calls in Netflix Hystrix commands, adding circuit breaking, fallbacks, and bulkhead isolation.
- **Feign JAX-RS** — Feign JAX-RS modules let developers reuse JAX-RS 1.x, 2.x, 3.x, and 4.x annotations on Feign client interfaces instead of Feign's native annotation set.
- **Feign SLF4J** — Feign SLF4J module routes Feign request and response logging through the SLF4J facade, integrating with the host application's logging backend.
- **Feign Form** — Feign Form module adds support for application/x-www-form-urlencoded and multipart/form-data request bodies, including file uploads.
- **Feign Micrometer** — Feign Micrometer module exposes Feign client metrics (timings, counts, errors) through Micrometer for shipment to Prometheus, Datadog, and other monitoring backends.

## Plans (1)

- **Feign Plans Pricing**

## Tags

HTTP Client, Java, JVM, Open-Source, REST, SDK

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/feign/). Scores are computed from the provider's own public artifacts under a published rubric.