Vidocq Documentation

Ravel is the MicroProfile Config 3.1 implementation of the Vidocq ecosystem. It implements the full configuration abstraction layer for Jakarta EE / MicroProfile applications: aggregation of multiple sources (system properties, environment variables, microprofile-config.properties), type conversion, property expressions, configuration profiles, and CDI integration via Vauban. Goal: 100 % MicroProfile Config 3.1 TCK conformance, zero external dependencies, JPMS-strict, jlink-ready.

Origin of the name

Maurice Ravel (1875-1937) was a master of orchestration - he knew how to weave disparate sources (strings, winds, percussion) into a coherent and hierarchical whole. This is exactly what a configuration system does: aggregate heterogeneous sources (files, environment variables, system properties) into a unified configuration.

Reference: Ravel on Wikipedia.

Ravel, the composer

Ravel, the configuration runtime

String section

System properties

Wind section

Environment variables

Percussion section

microprofile-config.properties and custom sources

Orchestration score

Config sources hierarchy (ordinal)

Harmonic resolution

Type converters and implicit converters

Thematic development

Property expressions (${key}, ${key:default})

Movement structure

Configuration profiles (%dev., %prod., %test.)

Ravel orchestrates all these voices into a single, unified configuration accessible via ConfigProvider.getConfig() and optionally injected via CDI with @ConfigProperty.

At a glance

Implemented spec

https://microprofile.io/specifications/microprofile-config/

Repo

https://codeberg.org/Vidocq/ravel

Java

25 (LTS)

JPMS modules

org.eclipse.microprofile.config (repackaged), io.vidocq.ravel.api, io.vidocq.ravel.core, io.vidocq.ravel.cdi.vauban

Runtime dependencies

MicroProfile Config spec only. CDI optional via Vauban.

jlink-ready

✅ - all dependencies have explicit module-info, no Automatic-Module-Name fallback.

TCK

✅ Target: 100 % PASS (M5 - May 2026).

Position in the ecosystem

flowchart LR
  App["Your application<br/>@ConfigProperty injection"]
  App -->|ConfigProvider.getConfig| Ravel["Ravel<br/>MicroProfile Config"]
  Ravel -->|cascading lookup| SysProp["System properties<br/>ordinal: 400"]
  Ravel -->|cascading lookup| EnvVar["Environment variables<br/>ordinal: 300"]
  Ravel -->|cascading lookup| Props["microprofile-config.properties<br/>ordinal: 100"]
  Ravel -->|cascading lookup| Custom["Custom ConfigSource<br/>via SPI"]

  Ravel -->|@Inject| Vauban["Vauban<br/>CDI Lite"]

  Ravel -->|type conversion| Converters["Built-in converters<br/>primitives, collections, temporal, etc."]
  Ravel -->|property resolution| Expressions["Property expressions<br/>${key}, ${key:default}"]
  Ravel -->|profile matching| Profiles["Config profiles<br/>%dev., %prod., %test."]

Key features

Zero external dependencies

Only org.eclipse.microprofile.config as a compile dependency. The implementation is fully self-contained, with no Smallrye, Guava, or other third-party libs. Perfect for embedded and microservices.

JPMS strict

All modules have explicit module-info.java, no automatic module fallbacks. Internal packages are not exported. Compatible with jlink for custom JDK images.

Built-in type converters

Supports primitives, boxes, String, URL, URI, InetAddress, Duration, Period, temporal types, enumerations, arrays, and collections - with implicit converters for custom types via public constructors or valueOf() / parse() methods.

Property expressions

Support for property references with ${key} and default values via ${key:default}. Cycle detection prevents infinite loops.

Configuration profiles

Environment-specific configuration via %dev., %prod., %test. prefixes. Profiles are resolved at lookup time, not build time.

CDI integration (optional)

Inject configuration values directly into beans via @ConfigProperty("key") and @ConfigProperty("key") on Optional<T> fields. Powered by Vauban Build-Compatible Extension.

Try it out

// Get the Config
Config config = ConfigProvider.getConfig();
String value = config.getValue("my.property", String.class);
Optional<String> optValue = config.getOptionalValue("my.property", String.class);

// With CDI
@ApplicationScoped
public class MyApplication {
    @Inject
    @ConfigProperty("app.name")
    String appName;

    @Inject
    @ConfigProperty("app.port")
    int port;

    @Inject
    @ConfigProperty("app.debug")
    Optional<Boolean> debug;
}

Next: Getting started.