Plugin System

Firefly plugins carry optional capabilities such as metrics, alerts, audit extensions, and future protocols. The lifecycle lives in plugins/plugin-api.

Plugin API

public interface FireflyPlugin extends AutoCloseable {
    String id();

    default FireflyPluginCompatibility compatibility() {
        return FireflyPluginCompatibility.current();
    }

    void start(FireflyPluginContext context);
}

compatibility() declares the supported host Plugin API-level range. The current API level is 1. Older 1.x plugins inherit a default level-1 declaration and do not need recompilation merely because Firefly moves to 1.0.2.

@Override
public FireflyPluginCompatibility compatibility() {
    return new FireflyPluginCompatibility(1, 2);
}

The host validates every enabled plugin before starting any plugin. An unsupported current level, invalid range, or duplicate ID prevents node startup rather than leaving a partially active plugin set. Product versions and Plugin API levels are independent; the API level advances only for a breaking SPI contract change.

Plugins read optional runtime capabilities from FireflyPluginContext:

FireflyPluginContext context = FireflyPluginContext.builder()
        .jobRepository(jobRepository)
        .nodeRegistry(nodeRegistry)
        .executorRegistry(executorRegistry)
        .build();

Enable Plugins

firefly.plugins=metrics-prometheus,acme-alerts

External plugins implement FireflyPlugin and expose a JDK SPI descriptor:

META-INF/services/com.firefly.plugin.FireflyPlugin

Netty is the default Executor transport, not a regular feature plugin.