Plugin Development Overview¶

erii plugins are based on the PF4J framework and built using the uesugi.erii-plugin Gradle convention plugin.

Extension Interfaces¶

Plugins support four extension interfaces:

Interface	Description
`AgentExtension`	General-purpose extension, always participates in the Agent decision loop
`RouteExtension`	Route extension, matched and invoked after LLM intent classification
`CmdExtension`	Command extension, matches `/xxx` format user commands
`PassiveExtension`	Passive extension, background tasks and event listeners

Plugins gain access to rich system capabilities through PluginContext:

Capability	Description
`mem`	In-memory cache (supports expiration policies)
`kv`	Key-value persistent storage
`blob`	File/binary storage
`vector`	Vector embedding and semantic retrieval
`config`	Plugin configuration reading
`database`	Database queries (chat history)
`scheduler`	Task scheduler (cron / interval / delay)
`llm`	LLM invocation
`http`	HTTP client
`server`	Register HTTP routes

erii supports two plugin development modes:

Class-based Development -- Suitable for complex plugins, providing fine-grained control over lifecycle and extension behavior
Annotation-based Development -- Suitable for simple plugins, declarative feature definition with KSP auto-generated code